[Title 40 CFR ]
[Code of Federal Regulations (annual edition) - July 1, 2019 Edition]
[From the U.S. Government Publishing Office]
[[Page i]]
Title 40
Protection of Environment
________________________
Part 60 (Appendices)
Revised as of July 1, 2019
Containing a codification of documents of general
applicability and future effect
As of July 1, 2019
Published by the Office of the Federal Register
National Archives and Records Administration as a
Special Edition of the Federal Register
[[Page ii]]
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Table of Contents
Page
Explanation................................................. v
Title 40:
Chapter I--Environmental Protection Agency
(Continued) 3
Finding Aids:
Table of CFR Titles and Chapters........................ 831
Alphabetical List of Agencies Appearing in the CFR...... 851
List of CFR sections Affected........................... 861
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Cite this Code: CFR
To cite the regulations in
this volume use title,
part and appendix letter.
Thus, 40 CFR 60,
appendices refers to title
40, part 60, appendix A.
----------------------------
[[Page v]]
EXPLANATION
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Each volume of the Code is revised at least once each calendar year
and issued on a quarterly basis approximately as follows:
Title 1 through Title 16.................................as of January 1
Title 17 through Title 27..................................as of April 1
Title 28 through Title 41...................................as of July 1
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collection request.
[[Page vi]]
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[[Page vii]]
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Oliver A. Potts,
Director,
Office of the Federal Register.
July 1, 2019.
[[Page ix]]
THIS TITLE
Title 40--Protection of Environment is composed of thirty-seven
volumes. The parts in these volumes are arranged in the following order:
Parts 1-49, parts 50-51, part 52 (52.01-52.1018), part 52 (52.1019-
52.2019), part 52 (52.2020-end of part 52), parts 53-59, part 60 (60.1-
60.499), part 60 (60.500-end of part 60, sections), part 60
(Appendices), parts 61-62, part 63 (63.1-63.599), part 63 (63.600-
63.1199), part 63 (63.1200-63.1439), part 63 (63.1440-63.6175), part 63
(63.6580-63.8830), part 63 (63.8980-end of part 63), parts 64-71, parts
72-79, part 80, part 81, parts 82-86, parts 87-95, parts 96-99, parts
100-135, parts 136-149, parts 150-189, parts 190-259, parts 260-265,
parts 266-299, parts 300-399, parts 400-424, parts 425-699, parts 700-
722, parts 723-789, parts 790-999, parts 1000-1059, and part 1060 to
end. The contents of these volumes represent all current regulations
codified under this title of the CFR as of July 1, 2019.
Chapter I--Environmental Protection Agency appears in all thirty-
seven volumes. OMB control numbers for title 40 appear in Sec. 9.1 of
this chapter.
Chapters IV-VIII--Regulations issued by the Environmental Protection
Agency and Department of Justice, Council on Environmental Quality,
Chemical Safety and Hazard Investigation Board, Environmental Protection
Agency and Department of Defense; Uniform National Discharge Standards
for Vessels of the Armed Forces, and the Gulf Coast Ecosystem
Restoration Council appear in volume thirty seven.
For this volume, Ann Worley was Chief Editor. The Code of Federal
Regulations publication program is under the direction of John Hyrum
Martinez, assisted by Stephen J. Frattini.
[[Page 1]]
TITLE 40--PROTECTION OF ENVIRONMENT
(This book contains part 60, appendices)
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Part
chapter i--Environmental Protection Agency (Continued)...... 60
[[Page 3]]
CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
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Editorial Note: Nomenclature changes to chapter I appear at 65 FR
47324, 47325, Aug. 2, 2000.
SUBCHAPTER C--AIR PROGRAMS (CONTINUED)
Part Page
60 Part 60--Standards of performance for new
stationary sources (Continued).......... 5
[[Page 5]]
SUBCHAPTER C_AIR PROGRAMS (CONTINUED)
PART 60_STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES (CONTINUED)--
Table of Contents
App.
Appendix A-1 to Part 60--Test Methods 1 through 2F
Appendix A-2 to Part 60--Test Methods 2G through 3C
Appendix A-3 to Part 60--Test Methods 4 through 5I
Appendix A-4 to Part 60--Test Methods 6 through 10B
Appendix A-5 to Part 60--Test Methods 11 through 15A
Appendix A-6 to Part 60--Test Methods 16 through 18
Appendix A-7 to Part 60--Test Methods 19 through 25E
Appendix A-8 to Part 60--Test Methods 26 through 29
Appendix B to Part 60--Performance Specifications
Appendix C to Part 60--Determination of Emission Rate Change
Appendix D to Part 60--Required Emission Inventory Information
Appendix E to Part 60 [Reserved]
Appendix F to Part 60--Quality Assurance Procedures
Appendix G to Part 60--Provisions for an Alternative Method of
Demonstrating Compliance with 40 CFR 60.43 for the Newton
Power Station of Central Illinois Public Service Company
Appendix H to Part 60 [Reserved]
Appendix I to Part 60--Owner's Manuals and Temporary Labels for Wood
Heaters Subject to Subparts AAA and QQQQ of Part 60
Authority: 42 U.S.C. 7401-7601.
Source: 36 FR 24877, Dec. 23, 1971, unless otherwise noted.
Sec. Appendix A-1 to Part 60--Test Methods 1 through 2F
Method 1--Sample and velocity traverses for stationary sources
Method 1A--Sample and velocity traverses for stationary sources with
small stacks or ducts
Method 2--Determination of stack gas velocity and volumetric flow rate
(Type S pitot tube)
Method 2A--Direct measurement of gas volume through pipes and small
ducts
Method 2B--Determination of exhaust gas volume flow rate from gasoline
vapor incinerators
Method 2C--Determination of gas velocity and volumetric flow rate in
small stacks or ducts (standard pitot tube)
Method 2D--Measurement of gas volume flow rates in small pipes and ducts
Method 2E--Determination of landfill gas production flow rate
Method 2F--Determination of Stack Gas Velocity and Volumetric Flow Rate
With Three-Dimensional Probes
The test methods in this appendix are referred to in Sec. 60.8
(Performance Tests) and Sec. 60.11 (Compliance With Standards and
Maintenance Requirements) of 40 CFR part 60, subpart A (General
Provisions). Specific uses of these test methods are described in the
standards of performance contained in the subparts, beginning with
Subpart D.
Within each standard of performance, a section title ``Test Methods
and Procedures'' is provided to: (1) Identify the test methods to be
used as reference methods to the facility subject to the respective
standard and (2) identify any special instructions or conditions to be
followed when applying a method to the respective facility. Such
instructions (for example, establish sampling rates, volumes, or
temperatures) are to be used either in addition to, or as a substitute
for procedures in a test method. Similarly, for sources subject to
emission monitoring requirements, specific instructions pertaining to
any use of a test method as a reference method are provided in the
subpart or in appendix B.
Inclusion of methods in this appendix is not intended as an
endorsement or denial of their applicability to sources that are not
subject to standards of performance. The methods are potentially
applicable to other sources; however, applicability should be confirmed
by careful and appropriate evaluation of the conditions prevalent at
such sources.
The approach followed in the formulation of the test methods
involves specifications for equipment, procedures, and performance. In
concept, a performance specification approach would be preferable in all
methods because this allows the greatest flexibility to the user. In
practice, however, this approach is impractical in most cases because
performance specifications cannot be established. Most of the methods
described herein, therefore, involve specific equipment specifications
and procedures, and only a few methods in this appendix rely on
performance criteria.
Minor changes in the test methods should not necessarily affect the
validity of the results and it is recognized that alternative and
equivalent methods exist. section 60.8 provides authority for the
Administrator to
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specify or approve (1) equivalent methods, (2) alternative methods, and
(3) minor changes in the methodology of the test methods. It should be
clearly understood that unless otherwise identified all such methods and
changes must have prior approval of the Administrator. An owner
employing such methods or deviations from the test methods without
obtaining prior approval does so at the risk of subsequent disapproval
and retesting with approved methods.
Within the test methods, certain specific equipment or procedures
are recognized as being acceptable or potentially acceptable and are
specifically identified in the methods. The items identified as
acceptable options may be used without approval but must be identified
in the test report. The potentially approvable options are cited as
``subject to the approval of the Administrator'' or as ``or
equivalent.'' Such potentially approvable techniques or alternatives may
be used at the discretion of the owner without prior approval. However,
detailed descriptions for applying these potentially approvable
techniques or alternatives are not provided in the test methods. Also,
the potentially approvable options are not necessarily acceptable in all
applications. Therefore, an owner electing to use such potentially
approvable techniques or alternatives is responsible for: (1) assuring
that the techniques or alternatives are in fact applicable and are
properly executed; (2) including a written description of the
alternative method in the test report (the written method must be clear
and must be capable of being performed without additional instruction,
and the degree of detail should be similar to the detail contained in
the test methods); and (3) providing any rationale or supporting data
necessary to show the validity of the alternative in the particular
application. Failure to meet these requirements can result in the
Administrator's disapproval of the alternative.
Method 1--Sample and Velocity Traverses for Stationary Sources
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling) essential to its
performance. Some material is incorporated by reference from other
methods in this part. Therefore, to obtain reliable results, persons
using this method should have a thorough knowledge of at least the
following additional test method: Method 2.
1.0 Scope and Application
1.1 Measured Parameters. The purpose of the method is to provide
guidance for the selection of sampling ports and traverse points at
which sampling for air pollutants will be performed pursuant to
regulations set forth in this part. Two procedures are presented: a
simplified procedure, and an alternative procedure (see section 11.5).
The magnitude of cyclonic flow of effluent gas in a stack or duct is the
only parameter quantitatively measured in the simplified procedure.
1.2 Applicability. This method is applicable to gas streams flowing
in ducts, stacks, and flues. This method cannot be used when: (1) the
flow is cyclonic or swirling; or (2) a stack is smaller than 0.30 meter
(12 in.) in diameter, or 0.071 m\2\ (113 in.\2\) in cross-sectional
area. The simplified procedure cannot be used when the measurement site
is less than two stack or duct diameters downstream or less than a half
diameter upstream from a flow disturbance.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
Note: The requirements of this method must be considered before
construction of a new facility from which emissions are to be measured;
failure to do so may require subsequent alterations to the stack or
deviation from the standard procedure. Cases involving variants are
subject to approval by the Administrator.
2.0 Summary of Method
2.1 This method is designed to aid in the representative measurement
of pollutant emissions and/or total volumetric flow rate from a
stationary source. A measurement site where the effluent stream is
flowing in a known direction is selected, and the cross-section of the
stack is divided into a number of equal areas. Traverse points are then
located within each of these equal areas.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and determine the applicability of regulatory limitations
prior to performing this test method.
6.0 Equipment and Supplies.
6.1 Apparatus. The apparatus described below is required only when
utilizing the alternative site selection procedure described in section
11.5 of this method.
6.1.1 Directional Probe. Any directional probe, such as United
Sensor Type DA Three-Dimensional Directional Probe, capable of measuring
both the pitch and yaw angles of gas flows is acceptable. Before using
the probe, assign an identification number to the
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directional probe, and permanently mark or engrave the number on the
body of the probe. The pressure holes of directional probes are
susceptible to plugging when used in particulate-laden gas streams.
Therefore, a procedure for cleaning the pressure holes by ``back-
purging'' with pressurized air is required.
6.1.2 Differential Pressure Gauges. Inclined manometers, U-tube
manometers, or other differential pressure gauges (e.g., magnehelic
gauges) that meet the specifications described in Method 2, section 6.2.
Note: If the differential pressure gauge produces both negative and
positive readings, then both negative and positive pressure readings
shall be calibrated at a minimum of three points as specified in Method
2, section 6.2.
7.0 Reagents and Standards [Reserved]
8.0 Sample Collection, Preservation, Storage, and Transport [Reserved]
9.0 Quality Control [Reserved]
10.0 Calibration and Standardization [Reserved]
11.0 Procedure
11.1 Selection of Measurement Site.
11.1.1 Sampling and/or velocity measurements are performed at a site
located at least eight stack or duct diameters downstream and two
diameters upstream from any flow disturbance such as a bend, expansion,
or contraction in the stack, or from a visible flame. If necessary, an
alternative location may be selected, at a position at least two stack
or duct diameters downstream and a half diameter upstream from any flow
disturbance.
11.1.2 An alternative procedure is available for determining the
acceptability of a measurement location not meeting the criteria above.
This procedure described in section 11.5 allows for the determination of
gas flow angles at the sampling points and comparison of the measured
results with acceptability criteria.
11.2 Determining the Number of Traverse Points.
11.2.1 Particulate Traverses.
11.2.1.1 When the eight- and two-diameter criterion can be met, the
minimum number of traverse points shall be: (1) twelve, for circular or
rectangular stacks with diameters (or equivalent diameters) greater than
0.61 meter (24 in.); (2) eight, for circular stacks with diameters
between 0.30 and 0.61 meter (12 and 24 in.); and (3) nine, for
rectangular stacks with equivalent diameters between 0.30 and 0.61 meter
(12 and 24 in.).
11.2.1.2 When the eight- and two-diameter criterion cannot be met,
the minimum number of traverse points is determined from Figure 1-1.
Before referring to the figure, however, determine the distances from
the measurement site to the nearest upstream and downstream
disturbances, and divide each distance by the stack diameter or
equivalent diameter, to determine the distance in terms of the number of
duct diameters. Then, determine from Figure 1-1 the minimum number of
traverse points that corresponds:
(1) To the number of duct diameters upstream; and
(2) To the number of diameters downstream. Select the higher of the
two minimum numbers of traverse points, or a greater value, so that for
circular stacks, the number is a multiple of 4, and for rectangular
stacks, the number is one of those shown in Table 1-1.
11.2.2 Velocity (Non-Particulate) Traverses. When velocity or
volumetric flow rate is to be determined (but not particulate matter),
the same procedure as that used for particulate traverses (Section
11.2.1) is followed, except that Figure 1-2 may be used instead of
Figure 1-1.
11.3 Cross-Sectional Layout and Location of Traverse Points.
11.3.1 Circular Stacks.
11.3.1.1 Locate the traverse points on two perpendicular diameters
according to Table 1-2 and the example shown in Figure 1-3. Any equation
(see examples in References 2 and 3 in section 16.0) that gives the same
values as those in Table 1-2 may be used in lieu of Table 1-2.
11.3.1.2 For particulate traverses, one of the diameters must
coincide with the plane containing the greatest expected concentration
variation (e.g., after bends); one diameter shall be congruent to the
direction of the bend. This requirement becomes less critical as the
distance from the disturbance increases; therefore, other diameter
locations may be used, subject to the approval of the Administrator.
11.3.1.3 In addition, for elliptical stacks having unequal
perpendicular diameters, separate traverse points shall be calculated
and located along each diameter. To determine the cross-sectional area
of the elliptical stack, use the following equation:
Square Area = D1 x D2 x 0.7854
Where: D1 = Stack diameter 1
D2 = Stack diameter 2
11.3.1.4 In addition, for stacks having diameters greater than 0.61
m (24 in.), no traverse points shall be within 2.5 centimeters (1.00
in.) of the stack walls; and for stack diameters equal to or less than
0.61 m (24 in.), no traverse points shall be located within 1.3 cm (0.50
in.) of the stack walls. To meet these criteria, observe the procedures
given below.
11.3.2 Stacks With Diameters Greater Than 0.61 m (24 in.).
[[Page 8]]
11.3.2.1 When any of the traverse points as located in section
11.3.1 fall within 2.5 cm (1.0 in.) of the stack walls, relocate them
away from the stack walls to: (1) a distance of 2.5 cm (1.0 in.); or (2)
a distance equal to the nozzle inside diameter, whichever is larger.
These relocated traverse points (on each end of a diameter) shall be the
``adjusted'' traverse points.
11.3.2.2 Whenever two successive traverse points are combined to
form a single adjusted traverse point, treat the adjusted point as two
separate traverse points, both in the sampling and/or velocity
measurement procedure, and in recording of the data.
11.3.3 Stacks With Diameters Equal To or Less Than 0.61 m (24 in.).
Follow the procedure in section 11.3.1.1, noting only that any
``adjusted'' points should be relocated away from the stack walls to:
(1) a distance of 1.3 cm (0.50 in.); or (2) a distance equal to the
nozzle inside diameter, whichever is larger.
11.3.4 Rectangular Stacks.
11.3.4.1 Determine the number of traverse points as explained in
sections 11.1 and 11.2 of this method. From Table 1-1, determine the
grid configuration. Divide the stack cross-section into as many equal
rectangular elemental areas as traverse points, and then locate a
traverse point at the centroid of each equal area according to the
example in Figure 1-4.
11.3.4.2 To use more than the minimum number of traverse points,
expand the ``minimum number of traverse points'' matrix (see Table 1-1)
by adding the extra traverse points along one or the other or both legs
of the matrix; the final matrix need not be balanced. For example, if a
4 x 3 ``minimum number of points'' matrix were expanded to 36 points,
the final matrix could be 9 x 4 or 12 x 3, and would not necessarily
have to be 6 x 6. After constructing the final matrix, divide the stack
cross-section into as many equal rectangular, elemental areas as
traverse points, and locate a traverse point at the centroid of each
equal area.
11.3.4.3 The situation of traverse points being too close to the
stack walls is not expected to arise with rectangular stacks. If this
problem should ever arise, the Administrator must be contacted for
resolution of the matter.
11.4 Verification of Absence of Cyclonic Flow.
11.4.1 In most stationary sources, the direction of stack gas flow
is essentially parallel to the stack walls. However, cyclonic flow may
exist (1) after such devices as cyclones and inertial demisters
following venturi scrubbers, or (2) in stacks having tangential inlets
or other duct configurations which tend to induce swirling; in these
instances, the presence or absence of cyclonic flow at the sampling
location must be determined. The following techniques are acceptable for
this determination.
11.4.2 Level and zero the manometer. Connect a Type S pitot tube to
the manometer and leak-check system. Position the Type S pitot tube at
each traverse point, in succession, so that the planes of the face
openings of the pitot tube are perpendicular to the stack cross-
sectional plane; when the Type S pitot tube is in this position, it is
at ``0[deg] reference.'' Note the differential pressure ([Delta]p)
reading at each traverse point. If a null (zero) pitot reading is
obtained at 0[deg] reference at a given traverse point, an acceptable
flow condition exists at that point. If the pitot reading is not zero at
0[deg] reference, rotate the pitot tube (up to 90[deg] yaw angle), until a null reading is obtained.
Carefully determine and record the value of the rotation angle ([alpha])
to the nearest degree. After the null technique has been applied at each
traverse point, calculate the average of the absolute values of [alpha];
assign [alpha] values of 0[deg] to those points for which no rotation
was required, and include these in the overall average. If the average
value of [alpha] is greater than 20[deg], the overall flow condition in
the stack is unacceptable, and alternative methodology, subject to the
approval of the Administrator, must be used to perform accurate sample
and velocity traverses.
11.5 The alternative site selection procedure may be used to
determine the rotation angles in lieu of the procedure outlined in
section 11.4.
11.5.1 Alternative Measurement Site Selection Procedure. This
alternative applies to sources where measurement locations are less than
2 equivalent or duct diameters downstream or less than one-half duct
diameter upstream from a flow disturbance. The alternative should be
limited to ducts larger than 24 in. in diameter where blockage and wall
effects are minimal. A directional flow-sensing probe is used to measure
pitch and yaw angles of the gas flow at 40 or more traverse points; the
resultant angle is calculated and compared with acceptable criteria for
mean and standard deviation.
Note: Both the pitch and yaw angles are measured from a line passing
through the traverse point and parallel to the stack axis. The pitch
angle is the angle of the gas flow component in the plane that INCLUDES
the traverse line and is parallel to the stack axis. The yaw angle is
the angle of the gas flow component in the plane PERPENDICULAR to the
traverse line at the traverse point and is measured from the line
passing through the traverse point and parallel to the stack axis.
11.5.2 Traverse Points. Use a minimum of 40 traverse points for
circular ducts and 42 points for rectangular ducts for the gas flow
angle determinations. Follow the procedure outlined in section 11.3 and
Table 1-1 or 1-2 for the location and layout of the traverse
[[Page 9]]
points. If the measurement location is determined to be acceptable
according to the criteria in this alternative procedure, use the same
traverse point number and locations for sampling and velocity
measurements.
11.5.3 Measurement Procedure.
11.5.3.1 Prepare the directional probe and differential pressure
gauges as recommended by the manufacturer. Capillary tubing or surge
tanks may be used to dampen pressure fluctuations. It is recommended,
but not required, that a pretest leak check be conducted. To perform a
leak check, pressurize or use suction on the impact opening until a
reading of at least 7.6 cm (3 in.) H2O registers on the
differential pressure gauge, then plug the impact opening. The pressure
of a leak-free system will remain stable for at least 15 seconds.
11.5.3.2 Level and zero the manometers. Since the manometer level
and zero may drift because of vibrations and temperature changes,
periodically check the level and zero during the traverse.
11.5.3.3 Position the probe at the appropriate locations in the gas
stream, and rotate until zero deflection is indicated for the yaw angle
pressure gauge. Determine and record the yaw angle. Record the pressure
gauge readings for the pitch angle, and determine the pitch angle from
the calibration curve. Repeat this procedure for each traverse point.
Complete a ``back-purge'' of the pressure lines and the impact openings
prior to measurements of each traverse point.
11.5.3.4 A post-test check as described in section 11.5.3.1 is
required. If the criteria for a leak-free system are not met, repair the
equipment, and repeat the flow angle measurements.
11.5.4 Calibration. Use a flow system as described in sections
10.1.2.1 and 10.1.2.2 of Method 2. In addition, the flow system shall
have the capacity to generate two test-section velocities: one between
365 and 730 m/min (1,200 and 2,400 ft/min) and one between 730 and 1,100
m/min (2,400 and 3,600 ft/min).
11.5.4.1 Cut two entry ports in the test section. The axes through
the entry ports shall be perpendicular to each other and intersect in
the centroid of the test section. The ports should be elongated slots
parallel to the axis of the test section and of sufficient length to
allow measurement of pitch angles while maintaining the pitot head
position at the test-section centroid. To facilitate alignment of the
directional probe during calibration, the test section should be
constructed of plexiglass or some other transparent material. All
calibration measurements should be made at the same point in the test
section, preferably at the centroid of the test section.
11.5.4.2 To ensure that the gas flow is parallel to the central axis
of the test section, follow the procedure outlined in section 11.4 for
cyclonic flow determination to measure the gas flow angles at the
centroid of the test section from two test ports located 90[deg] apart.
The gas flow angle measured in each port must be 2[deg] of 0[deg]. Straightening vanes should be
installed, if necessary, to meet this criterion.
11.5.4.3 Pitch Angle Calibration. Perform a calibration traverse
according to the manufacturer's recommended protocol in 5[deg]
increments for angles from -60[deg] to + 60[deg] at one velocity in each
of the two ranges specified above. Average the pressure ratio values
obtained for each angle in the two flow ranges, and plot a calibration
curve with the average values of the pressure ratio (or other suitable
measurement factor as recommended by the manufacturer) versus the pitch
angle. Draw a smooth line through the data points. Plot also the data
values for each traverse point. Determine the differences between the
measured data values and the angle from the calibration curve at the
same pressure ratio. The difference at each comparison must be within
2[deg] for angles between 0[deg] and 40[deg] and within 3[deg] for
angles between 40[deg] and 60[deg].
11.5.4.4 Yaw Angle Calibration. Mark the three-dimensional probe to
allow the determination of the yaw position of the probe. This is
usually a line extending the length of the probe and aligned with the
impact opening. To determine the accuracy of measurements of the yaw
angle, only the zero or null position need be calibrated as follows:
Place the directional probe in the test section, and rotate the probe
until the zero position is found. With a protractor or other angle
measuring device, measure the angle indicated by the yaw angle indicator
on the three-dimensional probe. This should be within 2[deg] of 0[deg].
Repeat this measurement for any other points along the length of the
pitot where yaw angle measurements could be read in order to account for
variations in the pitot markings used to indicate pitot head positions.
12.0 Data Analysis and Calculations
12.1 Nomenclature.
L = length.
n = total number of traverse points.
Pi = pitch angle at traverse point i, degree.
Ravg = average resultant angle, degree.
Ri = resultant angle at traverse point i, degree.
Sd = standard deviation, degree.
W = width.
Yi = yaw angle at traverse point i, degree.
12.2 For a rectangular cross section, an equivalent diameter
(De) shall be calculated using the following equation, to
determine the upstream and downstream distances:
[GRAPHIC] [TIFF OMITTED] TR17OC00.037
[[Page 10]]
12.3 If use of the alternative site selection procedure (Section
11.5 of this method) is required, perform the following calculations
using the equations below: the resultant angle at each traverse point,
the average resultant angle, and the standard deviation. Complete the
calculations retaining at least one extra significant figure beyond that
of the acquired data. Round the values after the final calculations.
12.3.1 Calculate the resultant angle at each traverse point:
[GRAPHIC] [TIFF OMITTED] TR17OC00.038
12.3.2 Calculate the average resultant for the measurements:
[GRAPHIC] [TIFF OMITTED] TR17OC00.039
12.3.3 Calculate the standard deviations:
[GRAPHIC] [TIFF OMITTED] TR17OC00.040
12.3.4 Acceptability Criteria. The measurement location is
acceptable if Ravg <=20[deg] and Sd <=10[deg].
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
1. Determining Dust Concentration in a Gas Stream, ASME Performance
Test Code No. 27. New York. 1957.
2. DeVorkin, Howard, et al. Air Pollution Source Testing Manual. Air
Pollution Control District. Los Angeles, CA. November 1963.
3. Methods for Determining of Velocity, Volume, Dust and Mist
Content of Gases. Western Precipitation Division of Joy Manufacturing
Co. Los Angeles, CA. Bulletin WP-50. 1968.
4. Standard Method for Sampling Stacks for Particulate Matter. In:
1971 Book of ASTM Standards, Part 23. ASTM Designation D 2928-71.
Philadelphia, PA. 1971.
5. Hanson, H.A., et al. Particulate Sampling Strategies for Large
Power Plants Including Nonuniform Flow. USEPA, ORD, ESRL, Research
Triangle Park, NC. EPA-600/2-76-170. June 1976.
6. Entropy Environmentalists, Inc. Determination of the Optimum
Number of Sampling Points: An Analysis of Method 1 Criteria.
Environmental Protection Agency. Research Triangle Park, NC. EPA
Contract No. 68-01-3172, Task 7.
7. Hanson, H.A., R.J. Davini, J.K. Morgan, and A.A. Iversen.
Particulate Sampling Strategies for Large Power Plants Including
Nonuniform Flow. USEPA, Research Triangle Park, NC. Publication No. EPA-
600/2-76-170. June 1976. 350 pp.
8. Brooks, E.F., and R.L. Williams. Flow and Gas Sampling Manual.
U.S. Environmental Protection Agency. Research Triangle Park, NC.
Publication No. EPA-600/2-76-203. July 1976. 93 pp.
9. Entropy Environmentalists, Inc. Traverse Point Study. EPA
Contract No. 68-02-3172. June 1977. 19 pp.
10. Brown, J. and K. Yu. Test Report: Particulate Sampling Strategy
in Circular Ducts. Emission Measurement Branch. U.S. Environmental
Protection Agency, Research Triangle Park, NC 27711. July 31, 1980. 12
pp.
11. Hawksley, P.G.W., S. Badzioch, and J.H. Blackett. Measurement of
Solids in Flue Gases. Leatherhead, England, The British Coal Utilisation
Research Association. 1961. pp. 129-133.
12. Knapp, K.T. The Number of Sampling Points Needed for
Representative Source Sampling. In: Proceedings of the Fourth National
Conference on Energy and Environment. Theodore, L. et al. (ed). Dayton,
Dayton section of the American Institute of Chemical Engineers. October
3-7, 1976. pp. 563-568.
13. Smith, W.S. and D.J. Grove. A Proposed Extension of EPA Method 1
Criteria. Pollution Engineering. XV (8):36-37. August 1983.
14. Gerhart, P.M. and M.J. Dorsey. Investigation of Field Test
Procedures for Large Fans. University of Akron. Akron, OH. (EPRI
Contract CS-1651). Final Report (RP-1649-5). December 1980.
15. Smith, W.S. and D.J. Grove. A New Look at Isokinetic Sampling--
Theory and Applications. Source Evaluation Society Newsletter. VIII
(3):19-24. August 1983.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
[[Page 11]]
[GRAPHIC] [TIFF OMITTED] TR27FE14.007
Table 1-1 Cross-Section Layout for Rectangular Stacks
------------------------------------------------------------------------
Number of tranverse points layout Matrix
------------------------------------------------------------------------
9...................................... 3 x 3
12..................................... 4 x 3
16..................................... 4 x 4
20..................................... 5 x 4
25..................................... 5 x 5
30..................................... 6 x 5
36..................................... 6 x 6
42..................................... 7 x 6
49..................................... 7 x 7
------------------------------------------------------------------------
Table 1-2--Location of Traverse Points in Circular Stacks
[Percent of stack diameter from inside wall to tranverse point]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Number of traverse points on a diameter
Traverse point number on a diameter -----------------------------------------------------------------------------------------------
2 4 6 8 10 12 14 16 18 20 22 24
--------------------------------------------------------------------------------------------------------------------------------------------------------
1....................................................... 14.6 6.7 4.4 3.2 2.6 2.1 1.8 1.6 1.4 1.3 1.1 1.1
2....................................................... 85.4 25.0 14.6 10.5 8.2 6.7 5.7 4.9 4.4 3.9 3.5 3.2
3....................................................... ...... 75.0 29.6 19.4 14.6 11.8 9.9 8.5 7.5 6.7 6.0 5.5
4....................................................... ...... 93.3 70.4 32.3 22.6 17.7 14.6 12.5 10.9 9.7 8.7 7.9
5....................................................... ...... ...... 85.4 67.7 34.2 25.0 20.1 16.9 14.6 12.9 11.6 10.5
6....................................................... ...... ...... 95.6 80.6 65.8 35.6 26.9 22.0 18.8 16.5 14.6 13.2
7....................................................... ...... ...... ...... 89.5 77.4 64.4 36.6 28.3 23.6 20.4 18.0 16.1
8....................................................... ...... ...... ...... 96.8 85.4 75.0 63.4 37.5 29.6 25.0 21.8 19.4
9....................................................... ...... ...... ...... ...... 91.8 82.3 73.1 62.5 38.2 30.6 26.2 23.0
10...................................................... ...... ...... ...... ...... 97.4 88.2 79.9 71.7 61.8 38.8 31.5 27.2
11...................................................... ...... ...... ...... ...... ...... 93.3 85.4 78.0 70.4 61.2 39.3 32.3
12...................................................... ...... ...... ...... ...... ...... 97.9 90.1 83.1 76.4 69.4 60.7 39.8
13...................................................... ...... ...... ...... ...... ...... ...... 94.3 87.5 81.2 75.0 68.5 60.2
14...................................................... ...... ...... ...... ...... ...... ...... 98.2 91.5 85.4 79.6 73.8 67.7
15...................................................... ...... ...... ...... ...... ...... ...... ...... 95.1 89.1 83.5 78.2 72.8
16...................................................... ...... ...... ...... ...... ...... ...... ...... 98.4 92.5 87.1 82.0 77.0
17...................................................... ...... ...... ...... ...... ...... ...... ...... ...... 95.6 90.3 85.4 80.6
[[Page 12]]
18...................................................... ...... ...... ...... ...... ...... ...... ...... ...... 98.6 93.3 88.4 83.9
19...................................................... ...... ...... ...... ...... ...... ...... ...... ...... ...... 96.1 91.3 86.8
20...................................................... ...... ...... ...... ...... ...... ...... ...... ...... ...... 98.7 94.0 89.5
21...................................................... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... 96.5 92.1
22...................................................... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... 98.9 94.5
23...................................................... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... 96.8
24...................................................... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... 99.9
--------------------------------------------------------------------------------------------------------------------------------------------------------
[GRAPHIC] [TIFF OMITTED] TR17OC00.043
Method 1A--Sample and Velocity Traverses for Stationary Sources With
Small Stacks or Ducts
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling) essential to its
performance. Some material is incorporated by reference from other
methods in this part. Therefore, to obtain reliable results, persons
using this method should have a thorough knowledge of at least the
following additional test method: Method 1.
1.0 Scope and Application
1.1 Measured Parameters. The purpose of the method is to provide
guidance for the selection of sampling ports and traverse points at
which sampling for air pollutants will be performed pursuant to
regulations set forth in this part.
1.2 Applicability. The applicability and principle of this method
are identical to Method 1, except its applicability is limited to stacks
or ducts. This method is applicable to flowing gas streams in ducts,
stacks, and flues of less than about 0.30 meter (12 in.) in diameter, or
0.071 m\2\ (113 in.\2\) in cross-sectional area, but equal to or greater
than about 0.10 meter (4 in.) in diameter, or 0.0081 m\2\ (12.57 in.\2\)
in cross-sectional area. This method cannot be used when the flow is
cyclonic or swirling.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 The method is designed to aid in the representative measurement
of pollutant emissions and/or total volumetric flow rate from a
stationary source. A measurement site or a pair of measurement sites
where the effluent stream is flowing in a known direction is (are)
selected. The cross-section of the stack is divided into a number of
equal areas. Traverse points are then located within each of these equal
areas.
2.2 In these small diameter stacks or ducts, the conventional Method
5 stack assembly (consisting of a Type S pitot tube attached to a
sampling probe, equipped with a nozzle and thermocouple) blocks a
significant portion of the cross-section of the duct and causes
inaccurate measurements. Therefore, for particulate matter (PM) sampling
in small stacks or ducts, the gas velocity is measured using a standard
pitot tube downstream of the actual emission sampling site.
[[Page 13]]
The straight run of duct between the PM sampling and velocity
measurement sites allows the flow profile, temporarily disturbed by the
presence of the sampling probe, to redevelop and stabilize.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and determine the applicability of regulatory limitations
prior to performing this test method.
6.0 Equipment and Supplies [Reserved]
7.0 Reagents and Standards [Reserved]
8.0 Sample Collection, Preservation, Storage, and Transport [Reserved]
9.0 Quality Control [Reserved]
10.0 Calibration and Standardization [Reserved]
11.0 Procedure
11.1 Selection of Measurement Site.
11.1.1 Particulate Measurements--Steady or Unsteady Flow. Select a
particulate measurement site located preferably at least eight
equivalent stack or duct diameters downstream and 10 equivalent
diameters upstream from any flow disturbances such as bends, expansions,
or contractions in the stack, or from a visible flame. Next, locate the
velocity measurement site eight equivalent diameters downstream of the
particulate measurement site (see Figure 1A-1). If such locations are
not available, select an alternative particulate measurement location at
least two equivalent stack or duct diameters downstream and two and one-
half diameters upstream from any flow disturbance. Then, locate the
velocity measurement site two equivalent diameters downstream from the
particulate measurement site. (See section 12.2 of Method 1 for
calculating equivalent diameters for a rectangular cross-section.)
11.1.2 PM Sampling (Steady Flow) or Velocity (Steady or Unsteady
Flow) Measurements. For PM sampling when the volumetric flow rate in a
duct is constant with respect to time, section 11.1.1 of Method 1 may be
followed, with the PM sampling and velocity measurement performed at one
location. To demonstrate that the flow rate is constant (within 10
percent) when PM measurements are made, perform complete velocity
traverses before and after the PM sampling run, and calculate the
deviation of the flow rate derived after the PM sampling run from the
one derived before the PM sampling run. The PM sampling run is
acceptable if the deviation does not exceed 10 percent.
11.2 Determining the Number of Traverse Points.
11.2.1 Particulate Measurements (Steady or Unsteady Flow). Use
Figure 1-1 of Method 1 to determine the number of traverse points to use
at both the velocity measurement and PM sampling locations. Before
referring to the figure, however, determine the distances between both
the velocity measurement and PM sampling sites to the nearest upstream
and downstream disturbances. Then divide each distance by the stack
diameter or equivalent diameter to express the distances in terms of the
number of duct diameters. Then, determine the number of traverse points
from Figure 1-1 of Method 1 corresponding to each of these four
distances. Choose the highest of the four numbers of traverse points (or
a greater number) so that, for circular ducts the number is a multiple
of four; and for rectangular ducts, the number is one of those shown in
Table 1-1 of Method 1. When the optimum duct diameter location criteria
can be satisfied, the minimum number of traverse points required is
eight for circular ducts and nine for rectangular ducts.
11.2.2 PM Sampling (Steady Flow) or only Velocity (Non-Particulate)
Measurements. Use Figure 1-2 of Method 1 to determine number of traverse
points, following the same procedure used for PM sampling as described
in section 11.2.1 of Method 1. When the optimum duct diameter location
criteria can be satisfied, the minimum number of traverse points
required is eight for circular ducts and nine for rectangular ducts.
11.3 Cross-sectional Layout, Location of Traverse Points, and
Verification of the Absence of Cyclonic Flow. Same as Method 1, sections
11.3 and 11.4, respectively.
12.0 Data Analysis and Calculations [Reserved]
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
Same as Method 1, section 16.0, References 1 through 6, with the
addition of the following:
1. Vollaro, Robert F. Recommended Procedure for Sample Traverses in
Ducts Smaller Than 12 Inches in Diameter. U.S. Environmental Protection
Agency, Emission Measurement Branch, Research Triangle Park, North
Carolina. January 1977.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
[[Page 14]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.044
Method 2--Determination of Stack Gas Velocity and Volumetric Flow Rate
(Type S Pitot Tube)
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling) essential to its
performance. Some material is incorporated by reference from other
methods in this part. Therefore, to obtain reliable results, persons
using this method should have a thorough knowledge of at least the
following additional test method: Method 1.
1.0 Scope and Application.
1.1 This method is applicable for the determination of the average
velocity and the volumetric flow rate of a gas stream.
1.2 This method is not applicable at measurement sites that fail to
meet the criteria of Method 1, section 11.1. Also, the method cannot be
used for direct measurement in cyclonic or swirling gas streams; section
11.4 of Method 1 shows how to determine cyclonic or swirling flow
conditions. When unacceptable conditions exist, alternative procedures,
subject to the approval of the Administrator, must be employed to
produce accurate flow rate determinations. Examples of such alternative
procedures are: (1) to install straightening vanes; (2) to calculate the
total volumetric flow rate stoichiometrically, or (3) to move to another
measurement site at which the flow is acceptable.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method.
2.1 The average gas velocity in a stack is determined from the gas
density and from measurement of the average velocity head with a Type S
(Stausscheibe or reverse type) pitot tube.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and determine the applicability of regulatory limitations
prior to performing this test method.
6.0 Equipment and Supplies
Specifications for the apparatus are given below. Any other
apparatus that has been demonstrated (subject to approval of the
Administrator) to be capable of meeting the specifications will be
considered acceptable.
6.1 Type S Pitot Tube.
6.1.1 Pitot tube made of metal tubing (e.g., stainless steel) as
shown in Figure 2-1. It is recommended that the external tubing diameter
(dimension Dt, Figure 2-2b) be between 0.48 and 0.95 cm (\3/
16\ and \3/8\ inch). There shall be an equal distance from the base of
each leg of the pitot tube to its face-opening plane (dimensions
PA and PB, Figure 2-2b); it is recommended that
this distance be between 1.05 and 1.50 times the external tubing
diameter. The face openings of the pitot tube shall, preferably, be
aligned as shown in Figure 2-2; however, slight misalignments of the
openings are permissible (see Figure 2-3).
6.1.2 The Type S pitot tube shall have a known coefficient,
determined as outlined in section 10.0. An identification number shall
be assigned to the pitot tube; this number shall be permanently marked
or engraved on
[[Page 15]]
the body of the tube. A standard pitot tube may be used instead of a
Type S, provided that it meets the specifications of sections 6.7 and
10.2. Note, however, that the static and impact pressure holes of
standard pitot tubes are susceptible to plugging in particulate-laden
gas streams. Therefore, whenever a standard pitot tube is used to
perform a traverse, adequate proof must be furnished that the openings
of the pitot tube have not plugged up during the traverse period. This
can be accomplished by comparing the velocity head ([Delta]p)
measurement recorded at a selected traverse point (readable [Delta]p
value) with a second [Delta]p measurement recorded after ``back
purging'' with pressurized air to clean the impact and static holes of
the standard pitot tube. If the before and after [Delta]p measurements
are within 5 percent, then the traverse data are acceptable. Otherwise,
the data should be rejected and the traverse measurements redone. Note
that the selected traverse point should be one that demonstrates a
readable [Delta]p value. If ``back purging'' at regular intervals is
part of a routine procedure, then comparative [Delta]p measurements
shall be conducted as above for the last two traverse points that
exhibit suitable [Delta]p measurements.
6.2 Differential Pressure Gauge. An inclined manometer or equivalent
device. Most sampling trains are equipped with a 10 in. (water column)
inclined-vertical manometer, having 0.01 in. H20 divisions on
the 0 to 1 in. inclined scale, and 0.1 in. H20 divisions on
the 1 to 10 in. vertical scale. This type of manometer (or other gauge
of equivalent sensitivity) is satisfactory for the measurement of
[Delta]p values as low as 1.27 mm (0.05 in.) H20. However, a
differential pressure gauge of greater sensitivity shall be used
(subject to the approval of the Administrator), if any of the following
is found to be true: (1) the arithmetic average of all [Delta]p readings
at the traverse points in the stack is less than 1.27 mm (0.05 in.)
H20; (2) for traverses of 12 or more points, more than 10
percent of the individual [Delta]p readings are below 1.27 mm (0.05 in.)
H20; or (3) for traverses of fewer than 12 points, more than
one [Delta]p reading is below 1.27 mm (0.05 in.) H20.
Reference 18 (see section 17.0) describes commercially available
instrumentation for the measurement of low-range gas velocities.
6.2.1 As an alternative to criteria (1) through (3) above, Equation
2-1 (Section 12.2) may be used to determine the necessity of using a
more sensitive differential pressure gauge. If T is greater than 1.05,
the velocity head data are unacceptable and a more sensitive
differential pressure gauge must be used.
Note: If differential pressure gauges other than inclined manometers
are used (e.g., magnehelic gauges), their calibration must be checked
after each test series. To check the calibration of a differential
pressure gauge, compare [Delta]p readings of the gauge with those of a
gauge-oil manometer at a minimum of three points, approximately
representing the range of [Delta]p values in the stack. If, at each
point, the values of [Delta]p as read by the differential pressure gauge
and gauge-oil manometer agree to within 5 percent, the differential
pressure gauge shall be considered to be in proper calibration.
Otherwise, the test series shall either be voided, or procedures to
adjust the measured [Delta]p values and final results shall be used,
subject to the approval of the Administrator.
6.3 Temperature Sensor. A thermocouple, liquid-filled bulb
thermometer, bimetallic thermometer, mercury-in-glass thermometer, or
other gauge capable of measuring temperatures to within 1.5 percent of
the minimum absolute stack temperature. The temperature sensor shall be
attached to the pitot tube such that the sensor tip does not touch any
metal; the gauge shall be in an interference-free arrangement with
respect to the pitot tube face openings (see Figure 2-1 and Figure 2-4).
Alternative positions may be used if the pitot tube-temperature gauge
system is calibrated according to the procedure of section 10.0.
Provided that a difference of not more than 1 percent in the average
velocity measurement is introduced, the temperature gauge need not be
attached to the pitot tube. This alternative is subject to the approval
of the Administrator.
6.4 Pressure Probe and Gauge. A piezometer tube and mercury- or
water-filled U-tube manometer capable of measuring stack pressure to
within 2.5 mm (0.1 in.) Hg. The static tap of a standard type pitot tube
or one leg of a Type S pitot tube with the face opening planes
positioned parallel to the gas flow may also be used as the pressure
probe.
6.5 Barometer. A mercury, aneroid, or other barometer capable of
measuring atmospheric pressure to within 2.54 mm (0.1 in.) Hg.
Note: The barometric pressure reading may be obtained from a nearby
National Weather Service station. In this case, the station value (which
is the absolute barometric pressure) shall be requested and an
adjustment for elevation differences between the weather station and
sampling point shall be made at a rate of minus 2.5 mm (0.1 in.) Hg per
30 m (100 ft) elevation increase or plus 2.5 mm (0.1 in.) Hg per 30 m
(100 ft.) for elevation decrease.
6.6 Gas Density Determination Equipment. Method 3 equipment, if
needed (see section 8.6), to determine the stack gas dry molecular
weight, and Method 4 (reference method) or Method 5 equipment for
moisture content determination. Other methods may be used subject to
approval of the Administrator.
[[Page 16]]
6.7 Calibration Pitot Tube. Calibration of the Type S pitot tube
requires a standard pitot tube for a reference. When calibration of the
Type S pitot tube is necessary (see Section 10.1), a standard pitot tube
shall be used for a reference. The standard pitot tube shall,
preferably, have a known coefficient, obtained directly from the
National Institute of Standards and Technology (NIST), Gaithersburg, MD
20899, (301) 975-2002; or by calibration against another standard pitot
tube with a NIST-traceable coefficient. Alternatively, a standard pitot
tube designed according to the criteria given in sections 6.7.1 through
6.7.5 below and illustrated in Figure 2-5 (see also References 7, 8, and
17 in section 17.0) may be used. Pitot tubes designed according to these
specifications will have baseline coefficients of 0.99 0.01.
6.7.1 Standard Pitot Design.
6.7.1.1 Hemispherical (shown in Figure 2-5), ellipsoidal, or conical
tip.
6.7.1.2 A minimum of six diameters straight run (based upon D, the
external diameter of the tube) between the tip and the static pressure
holes.
6.7.1.3 A minimum of eight diameters straight run between the static
pressure holes and the centerline of the external tube, following the
90[deg] bend.
6.7.1.4 Static pressure holes of equal size (approximately 0.1 D),
equally spaced in a piezometer ring configuration.
6.7.1.5 90[deg] bend, with curved or mitered junction.
6.8 Differential Pressure Gauge for Type S Pitot Tube Calibration.
An inclined manometer or equivalent. If the single-velocity calibration
technique is employed (see section 10.1.2.3), the calibration
differential pressure gauge shall be readable to the nearest 0.127 mm
(0.005 in.) H20. For multivelocity calibrations, the gauge
shall be readable to the nearest 0.127 mm (0.005 in.) H20 for
[Delta]p values between 1.27 and 25.4 mm (0.05 and 1.00 in.)
H20, and to the nearest 1.27 mm (0.05 in.) H20 for
[Delta]p values above 25.4 mm (1.00 in.) H20. A special, more
sensitive gauge will be required to read [Delta]p values below 1.27 mm
(0.05 in.) H20 (see Reference 18 in section 16.0).
7.0 Reagents and Standards [Reserved]
8.0 Sample Collection and Analysis
8.1 Set up the apparatus as shown in Figure 2-1. Capillary tubing or
surge tanks installed between the manometer and pitot tube may be used
to dampen [Delta]P fluctuations. It is recommended, but not required,
that a pretest leak-check be conducted as follows: (1) blow through the
pitot impact opening until at least 7.6 cm (3.0 in.) H2O
velocity head registers on the manometer; then, close off the impact
opening. The pressure shall remain stable (2.5 mm
H2O, 0.10 in. H2O) for at
least 15 seconds; (2) do the same for the static pressure side, except
using suction to obtain the minimum of 7.6 cm (3.0 in.) H2O.
Other leak-check procedures, subject to the approval of the
Administrator, may be used.
8.2 Level and zero the manometer. Because the manometer level and
zero may drift due to vibrations and temperature changes, make periodic
checks during the traverse (at least once per hour). Record all
necessary data on a form similar to that shown in Figure 2-6.
8.3 Measure the velocity head and temperature at the traverse points
specified by Method 1. Ensure that the proper differential pressure
gauge is being used for the range of [Delta]p values encountered (see
section 6.2). If it is necessary to change to a more sensitive gauge, do
so, and remeasure the [Delta]p and temperature readings at each traverse
point. Conduct a post-test leak-check (mandatory), as described in
section 8.1 above, to validate the traverse run.
8.4 Measure the static pressure in the stack. One reading is usually
adequate.
8.5 Determine the atmospheric pressure.
8.6 Determine the stack gas dry molecular weight. For combustion
processes or processes that emit essentially CO2,
O2, CO, and N2, use Method 3. For processes
emitting essentially air, an analysis need not be conducted; use a dry
molecular weight of 29.0. For other processes, other methods, subject to
the approval of the Administrator, must be used.
8.7 Obtain the moisture content from Method 4 (reference method, or
equivalent) or from Method 5.
8.8 Determine the cross-sectional area of the stack or duct at the
sampling location. Whenever possible, physically measure the stack
dimensions rather than using blueprints. Do not assume that stack
diameters are equal. Measure each diameter distance to verify its
dimensions.
9.0 Quality Control
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
10.1-10.4..................... Sampling Ensure accurate
equipment measurement of stack
calibration. gas flow rate,
sample volume.
------------------------------------------------------------------------
10.0 Calibration and Standardization
10.1 Type S Pitot Tube. Before its initial use, carefully examine
the Type S pitot tube top, side, and end views to verify that the face
openings of the tube are aligned within the specifications illustrated
in Figures 2-2
[[Page 17]]
and 2-3. The pitot tube shall not be used if it fails to meet these
alignment specifications. After verifying the face opening alignment,
measure and record the following dimensions of the pitot tube: (a) the
external tubing diameter (dimension Dt, Figure 2-2b); and (b)
the base-to-opening plane distances (dimensions PA and
PB, Figure 2-2b). If Dt is between 0.48 and 0.95
cm \3/16\ and \3/8\ in.), and if PA and PB are
equal and between 1.05 and 1.50 Dt, there are two possible
options: (1) the pitot tube may be calibrated according to the procedure
outlined in sections 10.1.2 through 10.1.5, or (2) a baseline (isolated
tube) coefficient value of 0.84 may be assigned to the pitot tube. Note,
however, that if the pitot tube is part of an assembly, calibration may
still be required, despite knowledge of the baseline coefficient value
(see section 10.1.1). If Dt, PA, and PB
are outside the specified limits, the pitot tube must be calibrated as
outlined in sections 10.1.2 through 10.1.5.
10.1.1 Type S Pitot Tube Assemblies. During sample and velocity
traverses, the isolated Type S pitot tube is not always used; in many
instances, the pitot tube is used in combination with other source-
sampling components (e.g., thermocouple, sampling probe, nozzle) as part
of an ``assembly.'' The presence of other sampling components can
sometimes affect the baseline value of the Type S pitot tube coefficient
(Reference 9 in section 17.0); therefore, an assigned (or otherwise
known) baseline coefficient value may or may not be valid for a given
assembly. The baseline and assembly coefficient values will be identical
only when the relative placement of the components in the assembly is
such that aerodynamic interference effects are eliminated. Figures 2-4,
2-7, and 2-8 illustrate interference-free component arrangements for
Type S pitot tubes having external tubing diameters between 0.48 and
0.95 cm (\3/16\ and \3/8\ in.). Type S pitot tube assemblies that fail
to meet any or all of the specifications of Figures 2-4, 2-7, and 2-8
shall be calibrated according to the procedure outlined in sections
10.1.2 through 10.1.5, and prior to calibration, the values of the
intercomponent spacings (pitot-nozzle, pitot-thermocouple, pitot-probe
sheath) shall be measured and recorded.
Note: Do not use a Type S pitot tube assembly that is constructed
such that the impact pressure opening plane of the pitot tube is below
the entry plane of the nozzle (see Figure 2-7B).
10.1.2 Calibration Setup. If the Type S pitot tube is to be
calibrated, one leg of the tube shall be permanently marked A, and the
other, B. Calibration shall be performed in a flow system having the
following essential design features:
10.1.2.1 The flowing gas stream must be confined to a duct of
definite cross-sectional area, either circular or rectangular. For
circular cross sections, the minimum duct diameter shall be 30.48 cm (12
in.); for rectangular cross sections, the width (shorter side) shall be
at least 25.4 cm (10 in.).
10.1.2.2 The cross-sectional area of the calibration duct must be
constant over a distance of 10 or more duct diameters. For a rectangular
cross section, use an equivalent diameter, calculated according to
Equation 2-2 (see section 12.3), to determine the number of duct
diameters. To ensure the presence of stable, fully developed flow
patterns at the calibration site, or ``test section,'' the site must be
located at least eight diameters downstream and two diameters upstream
from the nearest disturbances.
Note: The eight- and two-diameter criteria are not absolute; other
test section locations may be used (subject to approval of the
Administrator), provided that the flow at the test site has been
demonstrated to be or found stable and parallel to the duct axis.
10.1.2.3 The flow system shall have the capacity to generate a test-
section velocity around 910 m/min (3,000 ft/min). This velocity must be
constant with time to guarantee constant and steady flow during the
entire period of calibration. A centrifugal fan is recommended for this
purpose, as no flow rate adjustment for back pressure of the fan is
allowed during the calibration process. Note that Type S pitot tube
coefficients obtained by single-velocity calibration at 910 m/min (3,000
ft/min) will generally be valid to 3 percent for
the measurement of velocities above 300 m/min (1,000 ft/min) and to
6 percent for the measurement of velocities
between 180 and 300 m/min (600 and 1,000 ft/min). If a more precise
correlation between the pitot tube coefficient (Cp) and velocity is
desired, the flow system should have the capacity to generate at least
four distinct, time-invariant test-section velocities covering the
velocity range from 180 to 1,500 m/min (600 to 5,000 ft/min), and
calibration data shall be taken at regular velocity intervals over this
range (see References 9 and 14 in section 17.0 for details).
10.1.2.4 Two entry ports, one for each of the standard and Type S
pitot tubes, shall be cut in the test section. The standard pitot entry
port shall be located slightly downstream of the Type S port, so that
the standard and Type S impact openings will lie in the same cross-
sectional plane during calibration. To facilitate alignment of the pitot
tubes during calibration, it is advisable that the test section be
constructed of Plexiglas \TM\ or some other transparent material.
10.1.3 Calibration Procedure. Note that this procedure is a general
one and must not be used without first referring to the special
considerations presented in section 10.1.5. Note also that this
procedure applies only to
[[Page 18]]
single-velocity calibration. To obtain calibration data for the A and B
sides of the Type S pitot tube, proceed as follows:
10.1.3.1 Make sure that the manometer is properly filled and that
the oil is free from contamination and is of the proper density. Inspect
and leak-check all pitot lines; repair or replace if necessary.
10.1.3.2 Level and zero the manometer. Switch on the fan, and allow
the flow to stabilize. Seal the Type S pitot tube entry port.
10.1.3.3 Ensure that the manometer is level and zeroed. Position the
standard pitot tube at the calibration point (determined as outlined in
section 10.1.5.1), and align the tube so that its tip is pointed
directly into the flow. Particular care should be taken in aligning the
tube to avoid yaw and pitch angles. Make sure that the entry port
surrounding the tube is properly sealed.
10.1.3.4 Read [Delta]pstd, and record its value in a data
table similar to the one shown in Figure 2-9. Remove the standard pitot
tube from the duct, and disconnect it from the manometer. Seal the
standard entry port. Make no adjustment to the fan speed or other wind
tunnel volumetric flow control device between this reading and the
corresponding Type S pitot reading.
10.1.3.5 Connect the Type S pitot tube to the manometer and leak-
check. Open the Type S tube entry port. Check the manometer level and
zero. Insert and align the Type S pitot tube so that its A side impact
opening is at the same point as was the standard pitot tube and is
pointed directly into the flow. Make sure that the entry port
surrounding the tube is properly sealed.
10.1.3.6 Read [Delta]ps, and enter its value in the data
table. Remove the Type S pitot tube from the duct, and disconnect it
from the manometer.
10.1.3.7 Repeat Steps 10.1.3.3 through 10.1.3.6 until three pairs of
[Delta]p readings have been obtained for the A side of the Type S pitot
tube, with all the paired observations conducted at a constant fan speed
(no changes to fan velocity between observed readings).
10.1.3.8 Repeat Steps 10.1.3.3 through 10.1.3.7 for the B side of
the Type S pitot tube.
10.1.3.9 Perform calculations as described in section 12.4. Use the
Type S pitot tube only if the values of [sigma]A and
[sigma]B are less than or equal to 0.01 and if the absolute
value of the difference between Cp(A) and Cp(B) is
0.01 or less.
10.1.4 Special Considerations.
10.1.4.1 Selection of Calibration Point.
10.1.4.1.1 When an isolated Type S pitot tube is calibrated, select
a calibration point at or near the center of the duct, and follow the
procedures outlined in section 10.1.3. The Type S pitot coefficients
measured or calculated, (i.e., Cp(A) and Cp(B))
will be valid, so long as either: (1) the isolated pitot tube is used;
or (2) the pitot tube is used with other components (nozzle,
thermocouple, sample probe) in an arrangement that is free from
aerodynamic interference effects (see Figures 2-4, 2-7, and 2-8).
10.1.4.1.2 For Type S pitot tube-thermocouple combinations (without
probe assembly), select a calibration point at or near the center of the
duct, and follow the procedures outlined in section 10.1.3. The
coefficients so obtained will be valid so long as the pitot tube-
thermocouple combination is used by itself or with other components in
an interference-free arrangement (Figures 2-4, 2-7, and 2-8).
10.1.4.1.3 For Type S pitot tube combinations with complete probe
assemblies, the calibration point should be located at or near the
center of the duct; however, insertion of a probe sheath into a small
duct may cause significant cross-sectional area interference and
blockage and yield incorrect coefficient values (Reference 9 in section
17.0). Therefore, to minimize the blockage effect, the calibration point
may be a few inches off-center if necessary, but no closer to the outer
wall of the wind tunnel than 4 inches. The maximum allowable blockage,
as determined by a projected-area model of the probe sheath, is 2
percent or less of the duct cross-sectional area (Figure 2-10a). If the
pitot and/or probe assembly blocks more than 2 percent of the cross-
sectional area at an insertion point only 4 inches inside the wind
tunnel, the diameter of the wind tunnel must be increased.
10.1.4.2 For those probe assemblies in which pitot tube-nozzle
interference is a factor (i.e., those in which the pitot-nozzle
separation distance fails to meet the specifications illustrated in
Figure 2-7A), the value of Cp(s) depends upon the amount of
free space between the tube and nozzle and, therefore, is a function of
nozzle size. In these instances, separate calibrations shall be
performed with each of the commonly used nozzle sizes in place. Note
that the single-velocity calibration technique is acceptable for this
purpose, even though the larger nozzle sizes (0.635 cm or \1/
4\ in.) are not ordinarily used for isokinetic sampling at velocities
around 910 m/min (3,000 ft/min), which is the calibration velocity. Note
also that it is not necessary to draw an isokinetic sample during
calibration (see Reference 19 in section 17.0).
10.1.4.3 For a probe assembly constructed such that its pitot tube
is always used in the same orientation, only one side of the pitot tube
needs to be calibrated (the side which will face the flow). The pitot
tube must still meet the alignment specifications of Figure 2-2 or 2-3,
however, and must have an average deviation ([sigma]) value of 0.01 or
less (see section 12.4.4).
10.1.5 Field Use and Recalibration.
10.1.5.1 Field Use.
10.1.5.1.1 When a Type S pitot tube (isolated or in an assembly) is
used in the field, the appropriate coefficient value (whether
[[Page 19]]
assigned or obtained by calibration) shall be used to perform velocity
calculations. For calibrated Type S pitot tubes, the A side coefficient
shall be used when the A side of the tube faces the flow, and the B side
coefficient shall be used when the B side faces the flow. Alternatively,
the arithmetic average of the A and B side coefficient values may be
used, irrespective of which side faces the flow.
10.1.5.1.2 When a probe assembly is used to sample a small duct,
30.5 to 91.4 cm (12 to 36 in.) in diameter, the probe sheath sometimes
blocks a significant part of the duct cross-section, causing a reduction
in the effective value of Cp(s). Consult Reference 9 (see
section 17.0) for details. Conventional pitot-sampling probe assemblies
are not recommended for use in ducts having inside diameters smaller
than 30.5 cm (12 in.) (see Reference 16 in section 17.0).
10.1.5.2 Recalibration.
10.1.5.2.1 Isolated Pitot Tubes. After each field use, the pitot
tube shall be carefully reexamined in top, side, and end views. If the
pitot face openings are still aligned within the specifications
illustrated in Figure 2-2 and Figure 2-3, it can be assumed that the
baseline coefficient of the pitot tube has not changed. If, however, the
tube has been damaged to the extent that it no longer meets the
specifications of Figure 2-2 and Figure 2-3, the damage shall either be
repaired to restore proper alignment of the face openings, or the tube
shall be discarded.
10.1.5.2.2 Pitot Tube Assemblies. After each field use, check the
face opening alignment of the pitot tube, as in section 10.1.5.2.1.
Also, remeasure the intercomponent spacings of the assembly. If the
intercomponent spacings have not changed and the face opening alignment
is acceptable, it can be assumed that the coefficient of the assembly
has not changed. If the face opening alignment is no longer within the
specifications of Figure 2-2 and Figure 2-3, either repair the damage or
replace the pitot tube (calibrating the new assembly, if necessary). If
the intercomponent spacings have changed, restore the original spacings,
or recalibrate the assembly.
10.2 Standard Pitot Tube (if applicable). If a standard pitot tube
is used for the velocity traverse, the tube shall be constructed
according to the criteria of section 6.7 and shall be assigned a
baseline coefficient value of 0.99. If the standard pitot tube is used
as part of an assembly, the tube shall be in an interference-free
arrangement (subject to the approval of the Administrator).
10.3 Temperature Sensors.
10.3.1 After each field use, calibrate dial thermometers, liquid-
filled bulb thermometers, thermocouple-potentiometer systems, and other
sensors at a temperature within 10 percent of the average absolute stack
temperature. For temperatures up to 405 [deg]C (761 [deg]F), use an ASTM
mercury-in-glass reference thermometer, or equivalent, as a reference.
Alternatively, either a reference thermocouple and potentiometer
(calibrated against NIST standards) or thermometric fixed points (e.g.,
ice bath and boiling water, corrected for barometric pressure) may be
used. For temperatures above 405 [deg]C (761 [deg]F), use a reference
thermocouple-potentiometer system calibrated against NIST standards or
an alternative reference, subject to the approval of the Administrator.
10.3.2 The temperature data recorded in the field shall be
considered valid. If, during calibration, the absolute temperature
measured with the sensor being calibrated and the reference sensor agree
within 1.5 percent, the temperature data taken in the field shall be
considered valid. Otherwise, the pollutant emission test shall either be
considered invalid or adjustments (if appropriate) of the test results
shall be made, subject to the approval of the Administrator.
10.4 Barometer. Calibrate the barometer used against a mercury
barometer or NIST-traceable barometer prior to each field test.
11.0 Analytical Procedure
Sample collection and analysis are concurrent for this method (see
section 8.0).
12.0 Data Analysis and Calculations
Carry out calculations, retaining at least one extra significant
figure beyond that of the acquired data. Round off figures after final
calculation.
12.1 Nomenclature.
A = Cross-sectional area of stack, m\2\ (ft\2\).
Bws = Water vapor in the gas stream (from Method 4 (reference
method) or Method 5), proportion by volume.
Cp = Pitot tube coefficient, dimensionless.
Cp(s) = Type S pitot tube coefficient, dimensionless.
Cp(std) = Standard pitot tube coefficient; use 0.99 if the
coefficient is unknown and the tube is designed according to
the criteria of sections 6.7.1 to 6.7.5 of this method.
De = Equivalent diameter.
K = 0.127 mm H2O (metric units). 0.005 in. H2O
(English units).
Kp = Velocity equation constant.
L = Length.
Md = Molecular weight of stack gas, dry basis (see section
8.6), g/g-mole (lb/lb-mole).
Ms = Molecular weight of stack gas, wet basis, g/g-mole (lb/
lb-mole).
n = Total number of traverse points.
Pbar = Barometric pressure at measurement site, mm Hg (in.
Hg).
Pg = Stack static pressure, mm Hg (in. Hg).
Ps = Absolute stack pressure (Pbar +
Pg), mm Hg (in. Hg),
Pstd = Standard absolute pressure, 760 mm Hg (29.92 in. Hg).
[[Page 20]]
Qsd = Dry volumetric stack gas flow rate corrected to
standard conditions, dscm/hr (dscf/hr).
T = Sensitivity factor for differential pressure gauges.
Ts(abavg) = Average absolute stack temperature, [deg]K
([deg]R).
= 273 + Ts for metric units,
= 460 + Ts for English units.
Ts = Stack temperature, [deg]C ([deg]F).
= 273 + Ts for metric units,
= 460 + Ts for English units.
Tstd = Standard absolute temperature, 293 [deg]K (528
[deg]R).
Vs = Average stack gas velocity, m/sec (ft/sec).
W = Width.
[Delta]p = Velocity head of stack gas, mm H2O (in.
H20).
[Delta]pi = Individual velocity head reading at traverse
point ``i'', mm (in.) H2O.
[Delta]pstd = Velocity head measured by the standard pitot
tube, cm (in.) H2O.
[Delta]ps = Velocity head measured by the Type S pitot tube,
cm (in.) H2O.
3600 = Conversion Factor, sec/hr.
18.0 = Molecular weight of water, g/g-mole (lb/lb-mole).
12.2 Calculate T as follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.045
12.3 Calculate De as follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.046
12.4 Calibration of Type S Pitot Tube.
12.4.1 For each of the six pairs of [Delta]p readings (i.e., three
from side A and three from side B) obtained in section 10.1.3, calculate
the value of the Type S pitot tube coefficient according to Equation 2-
3:
[GRAPHIC] [TIFF OMITTED] TR17OC00.047
12.4.2 Calculate Cp(A), the mean A-side coefficient, and
Cp(B), the mean B-side coefficient. Calculate the difference
between these two average values.
12.4.3 Calculate the deviation of each of the three A-side values of
Cp(s) from Cp(A), and the deviation of each of the
three B-side values of Cp(s) from Cp(B), using
Equation 2-4:
[GRAPHIC] [TIFF OMITTED] TR17OC00.048
12.4.4 Calculate [sigma] the average deviation from the mean, for
both the A and B sides of the pitot tube. Use Equation 2-5:
[GRAPHIC] [TIFF OMITTED] TR17OC00.049
12.5 Molecular Weight of Stack Gas.
[GRAPHIC] [TIFF OMITTED] TR17OC00.050
12.6 Average Stack Gas Velocity.
[[Page 21]]
[GRAPHIC] [TIFF OMITTED] TR27FE14.008
12.7 Average Stack Gas Dry Volumetric Flow Rate.
[GRAPHIC] [TIFF OMITTED] TR27FE14.027
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
1. Mark, L.S. Mechanical Engineers' Handbook. New York. McGraw-Hill
Book Co., Inc. 1951.
2. Perry, J.H., ed. Chemical Engineers' Handbook. New York. McGraw-
Hill Book Co., Inc. 1960.
3. Shigehara, R.T., W.F. Todd, and W.S. Smith. Significance of
Errors in Stack Sampling Measurements. U.S. Environmental Protection
Agency, Research Triangle Park, N.C. (Presented at the Annual Meeting of
the Air Pollution Control Association, St. Louis, MO., June 14-19,
1970).
4. Standard Method for Sampling Stacks for Particulate Matter. In:
1971 Book of ASTM Standards, Part 23. Philadelphia, PA. 1971. ASTM
Designation D 2928-71.
5. Vennard, J.K. Elementary Fluid Mechanics. New York. John Wiley
and Sons, Inc. 1947.
6. Fluid Meters--Their Theory and Application. American Society of
Mechanical Engineers, New York, N.Y. 1959.
7. ASHRAE Handbook of Fundamentals. 1972. p. 208.
8. Annual Book of ASTM Standards, Part 26. 1974. p. 648.
9. Vollaro, R.F. Guidelines for Type S Pitot Tube Calibration. U.S.
Environmental Protection Agency, Research Triangle Park, N.C. (Presented
at 1st Annual Meeting, Source Evaluation Society, Dayton, OH, September
18, 1975.)
10. Vollaro, R.F. A Type S Pitot Tube Calibration Study. U.S.
Environmental Protection Agency, Emission Measurement Branch, Research
Triangle Park, N.C. July 1974.
11. Vollaro, R.F. The Effects of Impact Opening Misalignment on the
Value of the Type S Pitot Tube Coefficient. U.S. Environmental
Protection Agency, Emission Measurement Branch, Research Triangle Park,
NC. October 1976.
12. Vollaro, R.F. Establishment of a Baseline Coefficient Value for
Properly Constructed Type S Pitot Tubes. U.S. Environmental Protection
Agency, Emission Measurement Branch, Research Triangle Park, NC.
November 1976.
13. Vollaro, R.F. An Evaluation of Single-Velocity Calibration
Technique as a Means
[[Page 22]]
of Determining Type S Pitot Tube Coefficients. U.S. Environmental
Protection Agency, Emission Measurement Branch, Research Triangle Park,
NC. August 1975.
14. Vollaro, R.F. The Use of Type S Pitot Tubes for the Measurement
of Low Velocities. U.S. Environmental Protection Agency, Emission
Measurement Branch, Research Triangle Park, NC. November 1976.
15. Smith, Marvin L. Velocity Calibration of EPA Type Source
Sampling Probe. United Technologies Corporation, Pratt and Whitney
Aircraft Division, East Hartford, CT. 1975.
16. Vollaro, R.F. Recommended Procedure for Sample Traverses in
Ducts Smaller than 12 Inches in Diameter. U.S. Environmental Protection
Agency, Emission Measurement Branch, Research Triangle Park, NC.
November 1976.
17. Ower, E. and R.C. Pankhurst. The Measurement of Air Flow, 4th
Ed. London, Pergamon Press. 1966.
18. Vollaro, R.F. A Survey of Commercially Available Instrumentation
for the Measurement of Low-Range Gas Velocities. U.S. Environmental
Protection Agency, Emission Measurement Branch, Research Triangle Park,
NC. November 1976. (Unpublished Paper).
19. Gnyp, A.W., et al. An Experimental Investigation of the Effect
of Pitot Tube-Sampling Probe Configurations on the Magnitude of the S
Type Pitot Tube Coefficient for Commercially Available Source Sampling
Probes. Prepared by the University of Windsor for the Ministry of the
Environment, Toronto, Canada. February 1975.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
[GRAPHIC] [TIFF OMITTED] TR17OC00.055
[[Page 23]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.056
[[Page 24]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.057
[[Page 25]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.058
[GRAPHIC] [TIFF OMITTED] TR17OC00.059
PLANT___________________________________________________________________
DATE____________________________________________________________________
[[Page 26]]
RUN NO._________________________________________________________________
STACK DIA. OR DIMENSIONS, m (in.)_______________________________________
BAROMETRIC PRESS., mm Hg (in. Hg)_______________________________________
CROSS SECTIONAL AREA, m\2\ (ft\2\)______________________________________
OPERATORS_______________________________________________________________
PITOT TUBE I.D. NO._____________________________________________________
AVG. COEFFICIENT, Cp =__________________________________________________
LAST DATE CALIBRATED____________________________________________________
------------------------------------------------------------------------
-------------------------------------------------------------------------
------------------------------------------------------------------------
SCHEMATIC OF STACK CROSS SECTION
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stack temperature
Traverse Pt. No. Vel. Hd., [Delta]p mm ----------------------------------------------- Pg mm Hg (in. Hg) ([Delta]p)\1/2\
(in.) H2O Ts, [deg]C ( [deg]F) Ts, [deg]K ([deg]R)
--------------------------------------------------------------------------------------------------------------------------------------------------------
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Average(1)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Figure 2-6. Velocity Traverse Data
[[Page 27]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.060
[GRAPHIC] [TIFF OMITTED] TR17OC00.061
PITOT TUBE IDENTIFICATION NUMBER:_______________________________________
DATE:___________________________________________________________________
CALIBRATED BY:__________________________________________________________
``A'' Side Calibration
----------------------------------------------------------------------------------------------------------------
[Delta]Pstd cm H2O [Delta]P(s) cm H2O Deviation Cp(s)--
Run No. (in H2O) (in H2O) Cp(s) Cp(A)
----------------------------------------------------------------------------------------------------------------
1
----------------------------------------------------------------------------------------------------------------
2
----------------------------------------------------------------------------------------------------------------
3
----------------------------------------------------------------------------------------------------------------
[[Page 28]]
Cp, avg
(SIDE A)
----------------------------------------------------------------------------------------------------------------
``B'' Side Calibration
----------------------------------------------------------------------------------------------------------------
[Delta]Pstd cm H2O [Delta]P(s) cm H2O Deviation Cp(s)--
Run No. (in H2O) (in H2O) Cp(s) Cp(B)
----------------------------------------------------------------------------------------------------------------
1
----------------------------------------------------------------------------------------------------------------
2
----------------------------------------------------------------------------------------------------------------
3
----------------------------------------------------------------------------------------------------------------
Cp, avg
(SIDE B)
----------------------------------------------------------------------------------------------------------------
[GRAPHIC] [TIFF OMITTED] TR17OC00.062
[Cp, avg (side A)--Cp, avg (side B)]*
*Must be less than or equal to 0.01
Figure 2-9. Pitot Tube Calibration Data
[GRAPHIC] [TIFF OMITTED] TR30AU16.003
Method 2A--Direct Measurement of Gas Volume Through Pipes and Small
Ducts
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling) essential to its
performance. Some material is incorporated by reference from other
methods in this part. Therefore, to obtain reliable results, persons
using this method should have
[[Page 29]]
a thorough knowledge of at least the following additional test methods:
Method 1, Method 2.
1.0 Scope and Application
1.1 This method is applicable for the determination of gas flow
rates in pipes and small ducts, either in-line or at exhaust positions,
within the temperature range of 0 to 50 [deg]C (32 to 122 [deg]F).
1.2 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 A gas volume meter is used to measure gas volume directly.
Temperature and pressure measurements are made to allow correction of
the volume to standard conditions.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and determine the applicability of regulatory limitations
prior to performing this test method.
6.0 Equipment and Supplies
Specifications for the apparatus are given below. Any other
apparatus that has been demonstrated (subject to approval of the
Administrator) to be capable of meeting the specifications will be
considered acceptable.
6.1 Gas Volume Meter. A positive displacement meter, turbine meter,
or other direct measuring device capable of measuring volume to within 2
percent. The meter shall be equipped with a temperature sensor (accurate
to within 2 percent of the minimum absolute
temperature) and a pressure gauge (accurate to within 2.5 mm Hg). The manufacturer's recommended capacity of
the meter shall be sufficient for the expected maximum and minimum flow
rates for the sampling conditions. Temperature, pressure, corrosive
characteristics, and pipe size are factors necessary to consider in
selecting a suitable gas meter.
6.2 Barometer. A mercury, aneroid, or other barometer capable of
measuring atmospheric pressure to within 2.5 mm
Hg.
Note: In many cases, the barometric reading may be obtained from a
nearby National Weather Service station, in which case the station value
(which is the absolute barometric pressure) shall be requested and an
adjustment for elevation differences between the weather station and
sampling point shall be applied at a rate of minus 2.5 mm (0.1 in.) Hg
per 30 m (100 ft) elevation increase or vice versa for elevation
decrease.
6.3 Stopwatch. Capable of measurement to within 1 second.
7.0 Reagents and Standards [Reserved]
8.0 Sample Collection and Analysis
8.1 Installation. As there are numerous types of pipes and small
ducts that may be subject to volume measurement, it would be difficult
to describe all possible installation schemes. In general, flange
fittings should be used for all connections wherever possible. Gaskets
or other seal materials should be used to assure leak-tight connections.
The volume meter should be located so as to avoid severe vibrations and
other factors that may affect the meter calibration.
8.2 Leak Test.
8.2.1 A volume meter installed at a location under positive pressure
may be leak-checked at the meter connections by using a liquid leak
detector solution containing a surfactant. Apply a small amount of the
solution to the connections. If a leak exists, bubbles will form, and
the leak must be corrected.
8.2.2 A volume meter installed at a location under negative pressure
is very difficult to test for leaks without blocking flow at the inlet
of the line and watching for meter movement. If this procedure is not
possible, visually check all connections to assure leak-tight seals.
8.3 Volume Measurement.
8.3.1 For sources with continuous, steady emission flow rates,
record the initial meter volume reading, meter temperature(s), meter
pressure, and start the stopwatch. Throughout the test period, record
the meter temperatures and pressures so that average values can be
determined. At the end of the test, stop the timer, and record the
elapsed time, the final volume reading, meter temperature, and pressure.
Record the barometric pressure at the beginning and end of the test run.
Record the data on a table similar to that shown in Figure 2A-1.
8.3.2 For sources with noncontinuous, non-steady emission flow
rates, use the procedure in section 8.3.1 with the addition of the
following: Record all the meter parameters and the start and stop times
corresponding to each process cyclical or noncontinuous event.
9.0 Quality Control
[[Page 30]]
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
10.1-10.4..................... Sampling Ensure accurate
equipment measurement of stack
calibration. gas flow rate,
sample volume.
------------------------------------------------------------------------
10.0 Calibration and Standardization
10.1 Volume Meter.
10.1.1 The volume meter is calibrated against a standard reference
meter prior to its initial use in the field. The reference meter is a
spirometer or liquid displacement meter with a capacity consistent with
that of the test meter.
10.1.2 Alternatively, a calibrated, standard pitot may be used as
the reference meter in conjunction with a wind tunnel assembly. Attach
the test meter to the wind tunnel so that the total flow passes through
the test meter. For each calibration run, conduct a 4-point traverse
along one stack diameter at a position at least eight diameters of
straight tunnel downstream and two diameters upstream of any bend,
inlet, or air mover. Determine the traverse point locations as specified
in Method 1. Calculate the reference volume using the velocity values
following the procedure in Method 2, the wind tunnel cross-sectional
area, and the run time.
10.1.3 Set up the test meter in a configuration similar to that used
in the field installation (i.e., in relation to the flow moving device).
Connect the temperature sensor and pressure gauge as they are to be used
in the field. Connect the reference meter at the inlet of the flow line,
if appropriate for the meter, and begin gas flow through the system to
condition the meters. During this conditioning operation, check the
system for leaks.
10.1.4 The calibration shall be performed during at least three
different flow rates. The calibration flow rates shall be about 0.3,
0.6, and 0.9 times the rated maximum flow rate of the test meter.
10.1.5 For each calibration run, the data to be collected include:
reference meter initial and final volume readings, the test meter
initial and final volume reading, meter average temperature and
pressure, barometric pressure, and run time. Repeat the runs at each
flow rate at least three times.
10.1.6 Calculate the test meter calibration coefficient as indicated
in section 12.2.
10.1.7 Compare the three Ym values at each of the flow
rates tested and determine the maximum and minimum values. The
difference between the maximum and minimum values at each flow rate
should be no greater than 0.030. Extra runs may be required to complete
this requirement. If this specification cannot be met in six successive
runs, the test meter is not suitable for use. In addition, the meter
coefficients should be between 0.95 and 1.05. If these specifications
are met at all the flow rates, average all the Ym values from
runs meeting the specifications to obtain an average meter calibration
coefficient, Ym.
10.1.8 The procedure above shall be performed at least once for each
volume meter. Thereafter, an abbreviated calibration check shall be
completed following each field test. The calibration of the volume meter
shall be checked with the meter pressure set at the average value
encountered during the field test. Three calibration checks (runs) shall
be performed using this average flow rate value. Calculate the average
value of the calibration factor. If the calibration has changed by more
than 5 percent, recalibrate the meter over the full range of flow as
described above.
Note: If the volume meter calibration coefficient values obtained
before and after a test series differ by more than 5 percent, the test
series shall either be voided, or calculations for the test series shall
be performed using whichever meter coefficient value (i.e., before or
after) gives the greater value of pollutant emission rate.
10.2 Temperature Sensor. After each test series, check the
temperature sensor at ambient temperature. Use an American Society for
Testing and Materials (ASTM) mercury-in-glass reference thermometer, or
equivalent, as a reference. If the sensor being checked agrees within 2
percent (absolute temperature) of the reference, the temperature data
collected in the field shall be considered valid. Otherwise, the test
data shall be considered invalid or adjustments of the results shall be
made, subject to the approval of the Administrator.
10.3 Barometer. Calibrate the barometer used against a mercury
barometer or NIST-traceable barometer prior to the field test.
11.0 Analytical Procedure
Sample collection and analysis are concurrent for this method (see
section 8.0).
12.0 Data Analysis and Calculations
Carry out calculations, retaining at least one extra decimal figure
beyond that of the acquired data. Round off figures after final
calculation.
12.1 Nomenclature.
f = Final reading.
i = Initial reading.
Pbar = Barometric pressure, mm Hg.
Pg = Average static pressure in volume meter, mm Hg.
Qs = Gas flow rate, m\3\/min, standard conditions.
[[Page 31]]
s = Standard conditions, 20 [deg]C and 760 mm Hg.
Tr = Reference meter average temperature, [deg]K ([deg]R).
Tm = Test meter average temperature, [deg]K ([deg]R).
Vr = Reference meter volume reading, m\3\.
Vm = Test meter volume reading, m\3\.
Ym = Test meter calibration coefficient, dimensionless.
[thetas] = Elapsed test period time, min.
12.2 Test Meter Calibration Coefficient.
[GRAPHIC] [TIFF OMITTED] TR27FE14.009
12.3 Volume.
[GRAPHIC] [TIFF OMITTED] TR17OC00.065
12.4 Gas Flow Rate.
[GRAPHIC] [TIFF OMITTED] TR17OC00.066
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
1. Rom, Jerome J. Maintenance, Calibration, and Operation of
Isokinetic Source Sampling Equipment. U.S. Environmental Protection
Agency, Research Triangle Park, NC. Publication No. APTD-0576. March
1972.
2. Wortman, Martin, R. Vollaro, and P.R. Westlin. Dry Gas Volume
Meter Calibrations. Source Evaluation Society Newsletter. Vol. 2, No. 2.
May 1977.
3. Westlin, P.R., and R.T. Shigehara. Procedure for Calibrating and
Using Dry Gas Volume Meters as Calibration Standards. Source Evaluation
Society Newsletter. Vol. 3, No. 1. February 1978.
17.0 Tables, Diagrams, Flowcharts, and Validation Data [Reserved]
Method 2B--Determination of Exhaust Gas Volume Flow Rate From Gasoline
Vapor Incinerators
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should also have a thorough knowledge of at
least the following additional test methods: Method 1, Method 2, Method
2A, Method 10, Method 25A, Method 25B.
1.0 Scope and Application
1.1 This method is applicable for the determination of exhaust
volume flow rate from incinerators that process gasoline vapors
consisting primarily of alkanes, alkenes, and/or arenes (aromatic
hydrocarbons). It is assumed that the amount of auxiliary fuel is
negligible.
1.2 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 Organic carbon concentration and volume flow rate are measured
at the incinerator inlet using either Method 25A or Method 25B and
Method 2A, respectively. Organic carbon, carbon dioxide
(CO2), and carbon monoxide (CO) concentrations are measured
at the outlet using either Method 25A or Method 25B and Method 10,
respectively. The ratio of total carbon at the incinerator inlet and
outlet is multiplied by the inlet volume to determine the exhaust volume
flow rate.
3.0 Definitions
Same as section 3.0 of Method 10 and Method 25A.
4.0 Interferences
Same as section 4.0 of Method 10.
[[Page 32]]
5.0 Safety
5.1 This method may involve hazardous materials, operations, and
equipment. This test method may not address all of the safety problems
associated with its use. It is the responsibility of the user of this
test method to establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to
performing this test method.
6.0 Equipment and Supplies
Same as section 6.0 of Method 2A, Method 10, and Method 25A and/or
Method 25B as applicable, with the addition of the following:
6.1 This analyzer must meet the specifications set forth in section
6.1.2 of Method 10, except that the span shall be 15 percent
CO2 by volume.
7.0 Reagents and Standards
Same as section 7.0 of Method 10 and Method 25A, with the following
addition and exceptions:
7.1 Carbon Dioxide Analyzer Calibration. CO2 gases
meeting the specifications set forth in section 7 of Method 6C are
required.
7.2 Hydrocarbon Analyzer Calibration. Methane shall not be used as a
calibration gas when performing this method.
7.3 Fuel Gas. If Method 25B is used to measure the organic carbon
concentrations at both the inlet and exhaust, no fuel gas is required.
8.0 Sample Collection and Analysis
8.1 Pre-test Procedures. Perform all pre-test procedures (e.g.,
system performance checks, leak checks) necessary to determine gas
volume flow rate and organic carbon concentration in the vapor line to
the incinerator inlet and to determine organic carbon, carbon monoxide,
and carbon dioxide concentrations at the incinerator exhaust, as
outlined in Method 2A, Method 10, and Method 25A and/or Method 25B as
applicable.
8.2 Sampling. At the beginning of the test period, record the
initial parameters for the inlet volume meter according to the
procedures in Method 2A and mark all of the recorder strip charts to
indicate the start of the test. Conduct sampling and analysis as
outlined in Method 2A, Method 10, and Method 25A and/or Method 25B as
applicable. Continue recording inlet organic and exhaust CO2,
CO, and organic concentrations throughout the test. During periods of
process interruption and halting of gas flow, stop the timer and mark
the recorder strip charts so that data from this interruption are not
included in the calculations. At the end of the test period, record the
final parameters for the inlet volume meter and mark the end on all of
the recorder strip charts.
8.3 Post-test Procedures. Perform all post-test procedures (e.g.,
drift tests, leak checks), as outlined in Method 2A, Method 10, and
Method 25A and/or Method 25B as applicable.
9.0 Quality Control
Same as section 9.0 of Method 2A, Method 10, and Method 25A.
10.0 Calibration and Standardization
Same as section 10.0 of Method 2A, Method 10, and Method 25A.
Note: If a manifold system is used for the exhaust analyzers, all
the analyzers and sample pumps must be operating when the analyzer
calibrations are performed.
10.1 If an analyzer output does not meet the specifications of the
method, invalidate the test data for the period. Alternatively,
calculate the exhaust volume results using initial calibration data and
using final calibration data and report both resulting volumes. Then,
for emissions calculations, use the volume measurement resulting in the
greatest emission rate or concentration.
11.0 Analytical Procedure
Sample collection and analysis are concurrent for this method (see
section 8.0).
12.0 Data Analysis and Calculations
Carry out the calculations, retaining at least one extra decimal
figure beyond that of the acquired data. Round off figures after the
final calculation.
12.1 Nomenclature.
COe = Mean carbon monoxide concentration in system exhaust,
ppm.
(CO2)a = Ambient carbon dioxide concentration, ppm
(if not measured during the test period, may be assumed to
equal the global monthly mean CO2 concentration
posted at http://www.esrl.noaa.gov/gmd/ccgg/trends/
global.htmlglobal_data).
(CO2)e = Mean carbon dioxide concentration in
system exhaust, ppm.
HCe = Mean organic concentration in system exhaust as defined
by the calibration gas, ppm.
Hci = Mean organic concentration in system inlet as defined
by the calibration gas, ppm.
Ke = Hydrocarbon calibration gas factor for the exhaust
hydrocarbon analyzer, unitless [equal to the number of carbon
atoms per molecule of the gas used to calibrate the analyzer
(2 for ethane, 3 for propane, etc.)].
Ki = Hydrocarbon calibration gas factor for the inlet
hydrocarbon analyzer, unitless.
Ves = Exhaust gas volume, m\3\.
Vis = Inlet gas volume, m\3\.
Qes = Exhaust gas volume flow rate, m\3\/min.
Qis = Inlet gas volume flow rate, m\3\/min.
[theta] = Sample run time, min.
S = Standard conditions: 20 [deg]C, 760 mm Hg.
[[Page 33]]
12.2 Concentrations. Determine mean concentrations of inlet
organics, outlet CO2, outlet CO, and outlet organics
according to the procedures in the respective methods and the analyzers'
calibration curves, and for the time intervals specified in the
applicable regulations.
12.3 Exhaust Gas Volume. Calculate the exhaust gas volume as
follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.067
12.4 Exhaust Gas Volume Flow Rate. Calculate the exhaust gas volume
flow rate as follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.210
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
Same as section 16.0 of Method 2A, Method 10, and Method 25A.
17.0 Tables, Diagrams, Flowcharts, and Validation Data [Reserved]
Method 2C--Determination of Gas Velocity and Volumetric Flow Rate in
Small Stacks or Ducts (Standard Pitot Tube)
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling) essential to its
performance. Some material is incorporated by reference from other
methods in this part. Therefore, to obtain reliable results, persons
using this method should also have a thorough knowledge of at least the
following additional test methods: Method 1, Method 2.
1.0 Scope and Application
1.1 This method is applicable for the determination of average
velocity and volumetric flow rate of gas streams in small stacks or
ducts. Limits on the applicability of this method are identical to those
set forth in Method 2, section 1.0, except that this method is limited
to stationary source stacks or ducts less than about 0.30 meter (12 in.)
in diameter, or 0.071 m\2\ (113 in.\2\) in cross-sectional area, but
equal to or greater than about 0.10 meter (4 in.) in diameter, or 0.0081
m\2\ (12.57 in.\2\) in cross-sectional area.
1.2 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 The average gas velocity in a stack or duct is determined from
the gas density and from measurement of velocity heads with a standard
pitot tube.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 This method may involve hazardous materials, operations, and
equipment. This test method may not address all of the safety problems
associated with its use. It is the responsibility of the user of this
test method to establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to
performing this test method.
6.0 Equipment and Supplies
Same as Method 2, section 6.0, with the exception of the following:
6.1 Standard Pitot Tube (instead of Type S). A standard pitot tube
which meets the specifications of section 6.7 of Method 2. Use a
coefficient of 0.99 unless it is calibrated against another standard
pitot tube with a NIST-traceable coefficient (see section 10.2 of Method
2).
6.2 Alternative Pitot Tube. A modified hemispherical-nosed pitot
tube (see Figure 2C-1), which features a shortened stem and enlarged
impact and static pressure holes. Use a coefficient of 0.99 unless it is
calibrated as mentioned in section 6.1 above. This pitot tube is useful
in particulate liquid droplet-laden gas streams when a ``back purge'' is
ineffective.
7.0 Reagents and Standards [Reserved]
8.0 Sample Collection and Analysis
8.1 Follow the general procedures in section 8.0 of Method 2, except
conduct the measurements at the traverse points specified in Method 1A.
The static and impact pressure holes of standard pitot tubes are
susceptible to plugging in particulate-laden gas streams. Therefore,
adequate proof that the openings of the pitot tube have not
[[Page 34]]
plugged during the traverse period must be furnished; this can be done
by taking the velocity head ([Delta]p) heading at the final traverse
point, cleaning out the impact and static holes of the standard pitot
tube by ``back-purging'' with pressurized air, and then taking another
[Delta]p reading. If the [Delta]p readings made before and after the air
purge are the same (within 5 percent) the traverse
is acceptable. Otherwise, reject the run. Note that if the [Delta]p at
the final traverse point is unsuitably low, another point may be
selected. If ``back purging'' at regular intervals is part of the
procedure, then take comparative [Delta]p readings, as above, for the
last two back purges at which suitably high [Delta]p readings are
observed.
9.0 Quality Control
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
10.0.......................... Sampling Ensure accurate
equipment measurement of stack
calibration. gas velocity head.
------------------------------------------------------------------------
10.0 Calibration and Standardization
Same as Method 2, sections 10.2 through 10.4.
11.0 Analytical Procedure
Sample collection and analysis are concurrent for this method (see
section 8.0).
12.0 Calculations and Data Analysis
Same as Method 2, section 12.0.
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
Same as Method 2, section 16.0.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
[GRAPHIC] [TIFF OMITTED] TR17OC00.068
Method 2D--Measurement of Gas Volume Flow Rates in Small Pipes and Ducts
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling) essential to its
performance. Some material is incorporated by reference from other
methods in this part. Therefore, to obtain reliable results, persons
using this method should also have a thorough knowledge of at least the
following additional test methods: Method 1, Method 2, and Method 2A.
1.0 Scope and Application
1.1 This method is applicable for the determination of the
volumetric flow rates of gas streams in small pipes and ducts. It can be
applied to intermittent or variable gas flows only with particular
caution.
[[Page 35]]
1.2 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 All the gas flow in the pipe or duct is directed through a
rotameter, orifice plate or similar device to measure flow rate or
pressure drop. The device has been previously calibrated in a manner
that insures its proper calibration for the gas being measured. Absolute
temperature and pressure measurements are made to allow correction of
volumetric flow rates to standard conditions.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 This method may involve hazardous materials, operations, and
equipment. This test method may not address all of the safety problems
associated with its use. It is the responsibility of the user of this
test method to establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to
performing this test method.
6.0 Equipment and Supplies
Specifications for the apparatus are given below. Any other
apparatus that has been demonstrated (subject to approval of the
Administrator) to be capable of meeting the specifications will be
considered acceptable.
6.1 Gas Metering Rate or Flow Element Device. A rotameter, orifice
plate, or other volume rate or pressure drop measuring device capable of
measuring the stack flow rate to within 5 percent.
The metering device shall be equipped with a temperature gauge accurate
to within 2 percent of the minimum absolute stack
temperature and a pressure gauge (accurate to within 5 mm Hg). The capacity of the metering device shall be
sufficient for the expected maximum and minimum flow rates at the stack
gas conditions. The magnitude and variability of stack gas flow rate,
molecular weight, temperature, pressure, dewpoint, and corrosive
characteristics, and pipe or duct size are factors to consider in
choosing a suitable metering device.
6.2 Barometer. Same as Method 2, section 6.5.
6.3 Stopwatch. Capable of measurement to within 1 second.
7.0 Reagents and Standards [Reserved]
8.0 Sample Collection and Analysis
8.1 Installation and Leak Check. Same as Method 2A, sections 8.1 and
8.2, respectively.
8.2 Volume Rate Measurement.
8.2.1 Continuous, Steady Flow. At least once an hour, record the
metering device flow rate or pressure drop reading, and the metering
device temperature and pressure. Make a minimum of 12 equally spaced
readings of each parameter during the test period. Record the barometric
pressure at the beginning and end of the test period. Record the data on
a table similar to that shown in Figure 2D-1.
8.2.2 Noncontinuous and Nonsteady Flow. Use volume rate devices with
particular caution. Calibration will be affected by variation in stack
gas temperature, pressure and molecular weight. Use the procedure in
section 8.2.1 with the addition of the following: Record all the
metering device parameters on a time interval frequency sufficient to
adequately profile each process cyclical or noncontinuous event. A
multichannel continuous recorder may be used.
9.0 Quality Control
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
10.0.......................... Sampling Ensure accurate
equipment measurement of stack
calibration. gas flow rate or
sample volume.
------------------------------------------------------------------------
10.0 Calibration and Standardization
Same as Method 2A, section 10.0, with the following exception:
10.1 Gas Metering Device. Same as Method 2A, section 10.1, except
calibrate the metering device with the principle stack gas to be
measured (examples: air, nitrogen) against a standard reference meter. A
calibrated dry gas meter is an acceptable reference meter. Ideally,
calibrate the metering device in the field with the actual gas to be
metered. For metering devices that have a volume rate readout, calculate
the test metering device calibration coefficient, Ym, for
each run shown in Equation 2D-2 section 12.3.
10.2 For metering devices that do not have a volume rate readout,
refer to the manufacturer's instructions to calculate the Vm2
corresponding to each Vr.
10.3 Temperature Gauge. Use the procedure and specifications in
Method 2A, section 10.2. Perform the calibration at a temperature that
approximates field test conditions.
10.4 Barometer. Calibrate the barometer used against a mercury
barometer or NIST-traceable barometer prior to the field test.
[[Page 36]]
11.0 Analytical Procedure.
Sample collection and analysis are concurrent for this method (see
section 8.0).
12.0 Data Analysis and Calculations
12.1 Nomenclature.
Pbar = Barometric pressure, mm Hg (in. Hg).
Pm = Test meter average static pressure, mm Hg (in. Hg).
Qr = Reference meter volume flow rate reading, m\3\/min
(ft\3\/min).
Qm = Test meter volume flow rate reading, m\3\/min (ft\3\/
min).
Tr = Absolute reference meter average temperature, [deg]K
([deg]R).
Tm = Absolute test meter average temperature, [deg]K
([deg]R).
Kl = 0.3855 [deg]K/mm Hg for metric units, = 17.65 [deg]R/in.
Hg for English units.
12.2 Gas Flow Rate.
[GRAPHIC] [TIFF OMITTED] TR17OC00.069
12.3 Test Meter Device Calibration Coefficient. Calculation for
testing metering device calibration coefficient, Ym.
[GRAPHIC] [TIFF OMITTED] TR17OC00.070
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
1. Spink, L.K. Principles and Practice of Flowmeter Engineering. The
Foxboro Company. Foxboro, MA. 1967.
2. Benedict, R.P. Fundamentals of Temperature, Pressure, and Flow
Measurements. John Wiley & Sons, Inc. New York, NY. 1969.
3. Orifice Metering of Natural Gas. American Gas Association.
Arlington, VA. Report No. 3. March 1978. 88 pp.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
Plant___________________________________________________________________
Date____________________________________________________________________
Run No._________________________________________________________________
Sample location_________________________________________________________
Barometric pressure (mm Hg):
Start___________________________________________________________________
Finish__________________________________________________________________
Operators_______________________________________________________________
Metering device No._____________________________________________________
Calibration coefficient_________________________________________________
Calibration gas_________________________________________________________
Date to recalibrate_____________________________________________________
----------------------------------------------------------------------------------------------------------------
Temperature
Time Flow rate reading Static Pressure ---------------------------------------
[mm Hg (in. Hg)] [deg]C ([deg]F) [deg]K ([deg]R)
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Average
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Figure 2D-1. Volume Flow Rate Measurement Data
Method 2E--Determination of Landfill Gas Production Flow Rate
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this
[[Page 37]]
method should also have a thorough knowledge of at least the following
additional test methods: Methods 2 and 3C.
1.0 Scope and Application
1.1 Applicability. This method applies to the measurement of
landfill gas (LFG) production flow rate from municipal solid waste
landfills and is used to calculate the flow rate of nonmethane organic
compounds (NMOC) from landfills.
1.2 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 Extraction wells are installed either in a cluster of three or
at five dispersed locations in the landfill. A blower is used to extract
LFG from the landfill. LFG composition, landfill pressures, and orifice
pressure differentials from the wells are measured and the landfill gas
production flow rate is calculated.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 Since this method is complex, only experienced personnel should
perform the test. Landfill gas contains methane, therefore explosive
mixtures may exist at or near the landfill. It is advisable to take
appropriate safety precautions when testing landfills, such as
refraining from smoking and installing explosion-proof equipment.
6.0 Equipment and Supplies
6.1 Well Drilling Rig. Capable of boring a 0.61 m (24 in.) diameter
hole into the landfill to a minimum of 75 percent of the landfill depth.
The depth of the well shall not extend to the bottom of the landfill or
the liquid level.
6.2 Gravel. No fines. Gravel diameter should be appreciably larger
than perforations stated in sections 6.10 and 8.2.
6.3 Bentonite.
6.4 Backfill Material. Clay, soil, and sandy loam have been found to
be acceptable.
6.5 Extraction Well Pipe. Minimum diameter of 3 in., constructed of
polyvinyl chloride (PVC), high density polyethylene (HDPE), fiberglass,
stainless steel, or other suitable nonporous material capable of
transporting landfill gas.
6.6 Above Ground Well Assembly. Valve capable of adjusting gas flow,
such as a gate, ball, or butterfly valve; sampling ports at the well
head and outlet; and a flow measuring device, such as an in-line orifice
meter or pitot tube. A schematic of the aboveground well head assembly
is shown in Figure 2E-1.
6.7 Cap. Constructed of PVC or HDPE.
6.8 Header Piping. Constructed of PVC or HDPE.
6.9 Auger. Capable of boring a 0.15-to 0.23-m (6-to 9-in.) diameter
hole to a depth equal to the top of the perforated section of the
extraction well, for pressure probe installation.
6.10 Pressure Probe. Constructed of PVC or stainless steel (316),
0.025-m (1-in.). Schedule 40 pipe. Perforate the bottom two-thirds. A
minimum requirement for perforations is slots or holes with an open area
equivalent to four 0.006-m (\1/4\-in.) diameter holes spaced 90[deg]
apart every 0.15 m (6 in.).
6.11 Blower and Flare Assembly. Explosion-proof blower, capable of
extracting LFG at a flow rate of 8.5 m\3\/min (300 ft\3\/min), a water
knockout, and flare or incinerator.
6.12 Standard Pitot Tube and Differential Pressure Gauge for Flow
Rate Calibration with Standard Pitot. Same as Method 2, sections 6.7 and
6.8.
6.13 Orifice Meter. Orifice plate, pressure tabs, and pressure
measuring device to measure the LFG flow rate.
6.14 Barometer. Same as Method 4, section 6.1.5.
6.15 Differential Pressure Gauge. Water-filled U-tube manometer or
equivalent, capable of measuring within 0.02 mm Hg (0.01 in.
H2O), for measuring the pressure of the pressure probes.
7.0 Reagents and Standards. Not Applicable
8.0 Sample Collection, Preservation, Storage, and Transport
8.1 Placement of Extraction Wells. The landfill owner or operator
may install a single cluster of three extraction wells in a test area or
space five equal-volume wells over the landfill. The cluster wells are
recommended but may be used only if the composition, age of the refuse,
and the landfill depth of the test area can be determined.
8.1.1 Cluster Wells. Consult landfill site records for the age of
the refuse, depth, and composition of various sections of the landfill.
Select an area near the perimeter of the landfill with a depth equal to
or greater than the average depth of the landfill and with the average
age of the refuse between 2 and 10 years old. Avoid areas known to
contain nondecomposable materials, such as concrete and asbestos. Locate
the cluster wells as shown in Figure 2E-2.
8.1.1.1 The age of the refuse in a test area will not be uniform, so
calculate a weighted average age of the refuse as shown in section 12.2.
8.1.2 Equal Volume Wells. Divide the sections of the landfill that
are at least 2 years old into five areas representing equal volumes.
Locate an extraction well near the center of each area.
[[Page 38]]
8.2 Installation of Extraction Wells. Use a well drilling rig to dig
a 0.6 m (24 in.) diameter hole in the landfill to a minimum of 75
percent of the landfill depth, not to extend to the bottom of the
landfill or the liquid level. Perforate the bottom two thirds of the
extraction well pipe. A minimum requirement for perforations is holes or
slots with an open area equivalent to 0.01-m (0.5-in.) diameter holes
spaced 90[deg] apart every 0.1 to 0.2 m (4 to 8 in.). Place the
extraction well in the center of the hole and backfill with gravel to a
level 0.30 m (1 ft) above the perforated section. Add a layer of
backfill material 1.2 m (4 ft) thick. Add a layer of bentonite 0.9 m (3
ft) thick, and backfill the remainder of the hole with cover material or
material equal in permeability to the existing cover material. The
specifications for extraction well installation are shown in Figure 2E-
3.
8.3 Pressure Probes. Shallow pressure probes are used in the check
for infiltration of air into the landfill, and deep pressure probes are
use to determine the radius of influence. Locate pressure probes along
three radial arms approximately 120[deg] apart at distances of 3, 15,
30, and 45 m (10, 50, 100, and 150 ft) from the extraction well. The
tester has the option of locating additional pressure probes at
distances every 15 m (50 feet) beyond 45 m (150 ft). Example placements
of probes are shown in Figure 2E-4. The 15-, 30-, and 45-m, (50-, 100-,
and 150-ft) probes from each well, and any additional probes located
along the three radial arms (deep probes), shall extend to a depth equal
to the top of the perforated section of the extraction wells. All other
probes (shallow probes) shall extend to a depth equal to half the depth
of the deep probes.
8.3.1 Use an auger to dig a hole, 0.15- to 0.23-m (6-to 9-in.) in
diameter, for each pressure probe. Perforate the bottom two thirds of
the pressure probe. A minimum requirement for perforations is holes or
slots with an open area equivalent to four 0.006-m (0.25-in.) diameter
holes spaced 90[deg] apart every 0.15 m (6 in.). Place the pressure
probe in the center of the hole and backfill with gravel to a level 0.30
m (1 ft) above the perforated section. Add a layer of backfill material
at least 1.2 m (4 ft) thick. Add a layer of bentonite at least 0.3 m (1
ft) thick, and backfill the remainder of the hole with cover material or
material equal in permeability to the existing cover material. The
specifications for pressure probe installation are shown in Figure 2E-5.
8.4 LFG Flow Rate Measurement. Place the flow measurement device,
such as an orifice meter, as shown in Figure 2E-1. Attach the wells to
the blower and flare assembly. The individual wells may be ducted to a
common header so that a single blower, flare assembly, and flow meter
may be used. Use the procedures in section 10.1 to calibrate the flow
meter.
8.5 Leak-Check. A leak-check of the above ground system is required
for accurate flow rate measurements and for safety. Sample LFG at the
well head sample port and at the outlet sample port. Use Method 3C to
determine nitrogen (N2) concentrations. Determine the
difference between the well head and outlet N2 concentrations
using the formula in section 12.3. The system passes the leak-check if
the difference is less than 10,000 ppmv.
8.6 Static Testing. Close the control valves on the well heads
during static testing. Measure the gauge pressure (Pg) at
each deep pressure probe and the barometric pressure (Pbar)
every 8 hours (hr) for 3 days. Convert the gauge pressure of each deep
pressure probe to absolute pressure using the equation in section 12.4.
Record as Pi (initial absolute pressure).
8.6.1 For each probe, average all of the 8-hr deep pressure probe
readings (Pi) and record as Pia (average absolute
pressure). Pia is used in section 8.7.5 to determine the
maximum radius of influence.
8.6.2 Measure the static flow rate of each well once during static
testing.
8.7 Short-Term Testing. The purpose of short-term testing is to
determine the maximum vacuum that can be applied to the wells without
infiltration of ambient air into the landfill. The short-term testing is
performed on one well at a time. Burn all LFG with a flare or
incinerator.
8.7.1 Use the blower to extract LFG from a single well at a rate at
least twice the static flow rate of the respective well measured in
section 8.6.2. If using a single blower and flare assembly and a common
header system, close the control valve on the wells not being measured.
Allow 24 hr for the system to stabilize at this flow rate.
8.7.2 Test for infiltration of air into the landfill by measuring
the gauge pressures of the shallow pressure probes and using Method 3C
to determine the LFG N2 concentration. If the LFG
N2 concentration is less than 5 percent and all of the
shallow probes have a positive gauge pressure, increase the blower
vacuum by 3.7 mm Hg (2 in. H2O), wait 24 hr, and repeat the
tests for infiltration. Continue the above steps of increasing blower
vacuum by 3.7 mm Hg (2 in. H2O), waiting 24 hr, and testing
for infiltration until the concentration of N2 exceeds 5
percent or any of the shallow probes have a negative gauge pressure.
When this occurs,reduce the blower vacuum to the maximum setting at
which the N2 concentration was less than 5 percent and the
gauge pressures of the shallow probes are positive.
8.7.3 At this blower vacuum, measure atmospheric pressure
(Pbar) every 8 hr for 24 hr, and record the LFG flow rate
(Qs) and the probe gauge pressures (Pf) for all of
the probes. Convert the gauge pressures of the
[[Page 39]]
deep probes to absolute pressures for each 8-hr reading at Qs
as shown in section 12.4.
8.7.4 For each probe, average the 8-hr deep pressure probe absolute
pressure readings and record as Pfa (the final average
absolute pressure).
8.7.5 For each probe, compare the initial average pressure
(Pia) from section 8.6.1 to the final average pressure
(Pfa). Determine the furthermost point from the well head
along each radial arm where Pfa <=Pia. This
distance is the maximum radius of influence (Rm), which is
the distance from the well affected by the vacuum. Average these values
to determine the average maximum radius of influence (Rma).
8.7.6 Calculate the depth (Dst) affected by the
extraction well during the short term test as shown in section 12.6. If
the computed value of Dst exceeds the depth of the landfill,
set Dst equal to the landfill depth.
8.7.7 Calculate the void volume (V) for the extraction well as shown
in section 12.7.
8.7.8 Repeat the procedures in section 8.7 for each well.
8.8 Calculate the total void volume of the test wells
(Vv) by summing the void volumes (V) of each well.
8.9 Long-Term Testing. The purpose of long-term testing is to
extract two void volumes of LFG from the extraction wells. Use the
blower to extract LFG from the wells. If a single Blower and flare
assembly and common header system are used, open all control valves and
set the blower vacuum equal to the highest stabilized blower vacuum
demonstrated by any individual well in section 8.7. Every 8 hr, sample
the LFG from the well head sample port, measure the gauge pressures of
the shallow pressure probes, the blower vacuum, the LFG flow rate, and
use the criteria for infiltration in section 8.7.2 and Method 3C to test
for infiltration. If infiltration is detected, do not reduce the blower
vacuum, instead reduce the LFG flow rate from the well by adjusting the
control valve on the well head. Adjust each affected well individually.
Continue until the equivalent of two total void volumes (Vv)
have been extracted, or until Vt = 2Vv.
8.9.1 Calculate Vt, the total volume of LFG extracted
from the wells, as shown in section 12.8.
8.9.2 Record the final stabilized flow rate as Qf and the
gauge pressure for each deep probe. If, during the long term testing,
the flow rate does not stabilize, calculate Qf by averaging
the last 10 recorded flow rates.
8.9.3 For each deep probe, convert each gauge pressure to absolute
pressure as in section 12.4. Average these values and record as
Psa. For each probe, compare Pia to
Psa. Determine the furthermost point from the well head along
each radial arm where Psa <=Pia. This distance is
the stabilized radius of influence. Average these values to determine
the average stabilized radius of influence (Rsa).
8.10 Determine the NMOC mass emission rate using the procedures in
section 12.9 through 12.15.
9.0 Quality Control
9.1 Miscellaneous Quality Control Measures.
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
10.1.......................... LFG flow rate Ensures accurate
meter measurement of LFG
calibration. flow rate and sample
volume
------------------------------------------------------------------------
10.0 Calibration and Standardization
10.1 LFG Flow Rate Meter (Orifice) Calibration Procedure. Locate a
standard pitot tube in line with an orifice meter. Use the procedures in
section 8, 12.5, 12.6, and 12.7 of Method 2 to determine the average dry
gas volumetric flow rate for at least five flow rates that bracket the
expected LFG flow rates, except in section 8.1, use a standard pitot
tube rather than a Type S pitot tube. Method 3C may be used to determine
the dry molecular weight. It may be necessary to calibrate more than one
orifice meter in order to bracket the LFG flow rates. Construct a
calibration curve by plotting the pressure drops across the orifice
meter for each flow rate versus the average dry gas volumetric flow rate
in m\3\/min of the gas.
11.0 Procedures [Reserved]
12.0 Data Analysis and Calculations
12.1 Nomenclature.
A = Age of landfill, yr.
Aavg = Average age of the refuse tested, yr.
Ai = Age of refuse in the ith fraction, yr.
Ar = Acceptance rate, Mg/yr.
CNMOC = NMOC concentration, ppmv as hexane (CNMOC
= Ct/6).
Co = Concentration of N2 at the outlet, ppmv.
Ct = NMOC concentration, ppmv (carbon equivalent) from Method
25C.
Cw = Concentration of N2 at the wellhead, ppmv.
D = Depth affected by the test wells, m.
Dst = Depth affected by the test wells in the short-term
test, m.
e = Base number for natural logarithms (2.718).
f = Fraction of decomposable refuse in the landfill.
[[Page 40]]
fi = Fraction of the refuse in the ith section.
k = Landfill gas generation constant, yr-1.
Lo = Methane generation potential, m\3\/Mg.
Lo' = Revised methane generation potential to account for the
amount of nondecomposable material in the landfill, m\3\/Mg.
Mi = Mass of refuse in the ith section, Mg.
Mr = Mass of decomposable refuse affected by the test well,
Mg.
Pbar = Atmospheric pressure, mm Hg.
Pf = Final absolute pressure of the deep pressure probes
during short-term testing, mm Hg.
Pfa = Average final absolute pressure of the deep pressure
probes during short-term testing, mm Hg.
Pgf = final gauge pressure of the deep pressure probes, mm
Hg.
Pgi = Initial gauge pressure of the deep pressure probes, mm
Hg.
Pi = Initial absolute pressure of the deep pressure probes
during static testing, mm Hg.
Pia = Average initial absolute pressure of the deep pressure
probes during static testing, mm Hg.
Ps = Final absolute pressure of the deep pressure probes
during long-term testing, mm Hg.
Psa = Average final absolute pressure of the deep pressure
probes during long-term testing, mm Hg.
Qf = Final stabilized flow rate, m\3\/min.
Qi = LFG flow rate measured at orifice meter during the ith
interval, m\3\/min.
Qs = Maximum LFG flow rate at each well determined by short-
term test, m\3\/min.
Qt = NMOC mass emission rate, m\3\/min.
Rm = Maximum radius of influence, m.
Rma = Average maximum radius of influence, m.
Rs = Stabilized radius of influence for an individual well,
m.
Rsa = Average stabilized radius of influence, m.
ti = Age of section i, yr.
tt = Total time of long-term testing, yr.
tvi = Time of the ith interval (usually 8), hr.
V = Void volume of test well, m\3\.
Vr = Volume of refuse affected by the test well, m\3\.
Vt = Total volume of refuse affected by the long-term
testing, m\3\.
Vv = Total void volume affected by test wells, m\3\.
WD = Well depth, m.
[rho] = Refuse density, Mg/m\3\ (Assume 0.64 Mg/m\3\ if data are
unavailable).
12.2 Use the following equation to calculate a weighted average age
of landfill refuse.
[GRAPHIC] [TIFF OMITTED] TR17OC00.071
12.3 Use the following equation to determine the difference in
N2 concentrations (ppmv) at the well head and outlet
location.
[GRAPHIC] [TIFF OMITTED] TR17OC00.072
12.4 Use the following equation to convert the gauge pressure
(Pg) of each initial deep pressure probe to absolute pressure
(Pi).
[GRAPHIC] [TIFF OMITTED] TR17OC00.073
12.5 Use the following equation to convert the gauge pressures of
the deep probes to absolute pressures for each 8-hr reading at
Qs.
[GRAPHIC] [TIFF OMITTED] TR17OC00.074
12.6 Use the following equation to calculate the depth
(Dst) affected by the extraction well during the short-term
test.
[GRAPHIC] [TIFF OMITTED] TR17OC00.075
12.7 Use the following equation to calculate the void volume for the
extraction well (V).
[GRAPHIC] [TIFF OMITTED] TR17OC00.076
12.8 Use the following equation to calculate Vt, the
total volume of LFG extracted from the wells.
[GRAPHIC] [TIFF OMITTED] TR17OC00.077
12.9 Use the following equation to calculate the depth affected by
the test well. If using cluster wells, use the average depth of the
wells for WD. If the value of D is greater than the depth of the
landfill, set D equal to the landfill depth.
[GRAPHIC] [TIFF OMITTED] TR17OC00.078
12.10 Use the following equation to calculate the volume of refuse
affected by the test well.
[GRAPHIC] [TIFF OMITTED] TR17OC00.079
12.11 Use the following equation to calculate the mass affected by
the test well.
[GRAPHIC] [TIFF OMITTED] TR17OC00.080
12.12 Modify Lo to account for the nondecomposable refuse
in the landfill.
[GRAPHIC] [TIFF OMITTED] TR17OC00.081
12.13 In the following equation, solve for k (landfill gas
generation constant) by iteration. A suggested procedure is to select a
value for k, calculate the left side of the equation, and if not equal
to zero, select another value for k. Continue this process until the
left hand side of the equation equals zero, 0.001.
[[Page 41]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.082
12.14 Use the following equation to determine landfill NMOC mass
emission rate if the yearly acceptance rate of refuse has been
consistent (10 percent) over the life of the landfill.
[GRAPHIC] [TIFF OMITTED] TR17OC00.083
12.15 Use the following equation to determine landfill NMOC mass
emission rate if the acceptance rate has not been consistent over the
life of the landfill.
[GRAPHIC] [TIFF OMITTED] TR17OC00.084
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
1. Same as Method 2, Appendix A, 40 CFR Part 60.
2. Emcon Associates, Methane Generation and Recovery from Landfills.
Ann Arbor Science, 1982.
3. The Johns Hopkins University, Brown Station Road Landfill Gas
Resource Assessment, Volume 1: Field Testing and Gas Recovery
Projections. Laurel, Maryland: October 1982.
4. Mandeville and Associates, Procedure Manual for Landfill Gases
Emission Testing.
5. Letter and attachments from Briggum, S., Waste Management of
North America, to Thorneloe, S., EPA. Response to July 28, 1988 request
for additional information. August 18, 1988.
6. Letter and attachments from Briggum, S., Waste Management of
North America, to Wyatt, S., EPA. Response to December 7, 1988 request
for additional information. January 16, 1989.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
[[Page 42]]
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[GRAPHIC] [TIFF OMITTED] TR17OC00.086
[[Page 44]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.087
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[GRAPHIC] [TIFF OMITTED] TR17OC00.088
[[Page 46]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.089
Method 2F--Determination of Stack Gas Velocity And Volumetric Flow Rate
With Three-Dimensional Probes
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling) essential to its
performance. Some material has been incorporated from other methods in
this part. Therefore, to obtain reliable results, those using this
method should have a thorough knowledge of at least the following
additional test methods: Methods 1, 2, 3 or 3A, and 4.
1.0 Scope and Application
1.1 This method is applicable for the determination of yaw angle, pitch
angle, axial velocity and the volumetric flow rate of a gas
[[Page 47]]
stream in a stack or duct using a three-dimensional (3-D) probe. This
method may be used only when the average stack or duct gas velocity is
greater than or equal to 20 ft/sec. When the above condition cannot be
met, alternative procedures, approved by the Administrator, U.S.
Environmental Protection Agency, shall be used to make accurate flow
rate determinations.
2.0 Summary of Method
2.1 A 3-D probe is used to determine the velocity pressure and the
yaw and pitch angles of the flow velocity vector in a stack or duct. The
method determines the yaw angle directly by rotating the probe to null
the pressure across a pair of symmetrically placed ports on the probe
head. The pitch angle is calculated using probe-specific calibration
curves. From these values and a determination of the stack gas density,
the average axial velocity of the stack gas is calculated. The average
gas volumetric flow rate in the stack or duct is then determined from
the average axial velocity.
3.0 Definitions
3.1. Angle-measuring Device Rotational Offset (RADO). The rotational
position of an angle-measuring device relative to the reference scribe
line, as determined during the pre-test rotational position check
described in section 8.3.
3.2 Axial Velocity. The velocity vector parallel to the axis of the
stack or duct that accounts for the yaw and pitch angle components of
gas flow. The term ``axial'' is used herein to indicate that the
velocity and volumetric flow rate results account for the measured yaw
and pitch components of flow at each measurement point.
3.3 Calibration Pitot Tube. The standard (Prandtl type) pitot tube
used as a reference when calibrating a 3-D probe under this method.
3.4 Field Test. A set of measurements conducted at a specific unit
or exhaust stack/duct to satisfy the applicable regulation (e.g., a
three-run boiler performance test, a single-or multiple-load nine-run
relative accuracy test).
3.5 Full Scale of Pressure-measuring Device. Full scale refers to
the upper limit of the measurement range displayed by the device. For
bi-directional pressure gauges, full scale includes the entire pressure
range from the lowest negative value to the highest positive value on
the pressure scale.
3.6 Main probe. Refers to the probe head and that section of probe
sheath directly attached to the probe head. The main probe sheath is
distinguished from probe extensions, which are sections of sheath added
onto the main probe to extend its reach.
3.7 ``May,'' ``Must,'' ``Shall,'' ``Should,'' and the imperative
form of verbs.
3.7.1 ``May'' is used to indicate that a provision of this method is
optional.
3.7.2 ``Must,'' ``Shall,'' and the imperative form of verbs (such as
``record'' or ``enter'') are used to indicate that a provision of this
method is mandatory.
3.7.3 ``Should'' is used to indicate that a provision of this method
is not mandatory, but is highly recommended as good practice.
3.8 Method 1. Refers to 40 CFR part 60, appendix A, ``Method 1--
Sample and velocity traverses for stationary sources.''
3.9 Method 2. Refers to 40 CFR part 60, appendix A, ``Method 2--
Determination of stack gas velocity and volumetric flow rate (Type S
pitot tube).''
3.10 Method 2G. Refers to 40 CFR part 60, appendix A, ``Method 2G--
Determination of stack gas velocity and volumetric flow rate with two-
dimensional probes.''
3.11 Nominal Velocity. Refers to a wind tunnel velocity setting that
approximates the actual wind tunnel velocity to within 1.5 m/sec (5 ft/sec).
3.12 Pitch Angle. The angle between the axis of the stack or duct
and the pitch component of flow, i.e., the component of the total
velocity vector in a plane defined by the traverse line and the axis of
the stack or duct. (Figure 2F-1 illustrates the ``pitch plane.'') From
the standpoint of a tester facing a test port in a vertical stack, the
pitch component of flow is the vector of flow moving from the center of
the stack toward or away from that test port. The pitch angle is the
angle described by this pitch component of flow and the vertical axis of
the stack.
3.13 Readability. For the purposes of this method, readability for
an analog measurement device is one half of the smallest scale division.
For a digital measurement device, it is the number of decimals displayed
by the device.
3.14 Reference Scribe Line. A line permanently inscribed on the main
probe sheath (in accordance with section 6.1.6.1) to serve as a
reference mark for determining yaw angles.
3.15 Reference Scribe Line Rotational Offset (RSLO). The
rotational position of a probe's reference scribe line relative to the
probe's yaw-null position, as determined during the yaw angle
calibration described in section 10.5.
3.16 Response Time. The time required for the measurement system to
fully respond to a change from zero differential pressure and ambient
temperature to the stable stack or duct pressure and temperature
readings at a traverse point.
3.17 Tested Probe. A 3-D probe that is being calibrated.
3.18 Three-dimensional (3-D) Probe. A directional probe used to
determine the velocity pressure and yaw and pitch angles in a flowing
gas stream.
[[Page 48]]
3.19 Traverse Line. A diameter or axis extending across a stack or
duct on which measurements of differential pressure and flow angles are
made.
3.20 Wind Tunnel Calibration Location. A point, line, area, or
volume within the wind tunnel test section at, along, or within which
probes are calibrated. At a particular wind tunnel velocity setting, the
average velocity pressures at specified points at, along, or within the
calibration location shall vary by no more than 2 percent or 0.3 mm
H2O (0.01 in. H2O), whichever is less restrictive,
from the average velocity pressure at the calibration pitot tube
location. Air flow at this location shall be axial, i.e., yaw and pitch
angles within 3[deg]. Compliance with these flow
criteria shall be demonstrated by performing the procedures prescribed
in sections 10.1.1 and 10.1.2. For circular tunnels, no part of the
calibration location may be closer to the tunnel wall than 10.2 cm (4
in.) or 25 percent of the tunnel diameter, whichever is farther from the
wall. For elliptical or rectangular tunnels, no part of the calibration
location may be closer to the tunnel wall than 10.2 cm (4 in.) or 25
percent of the applicable cross-sectional axis, whichever is farther
from the wall.
3.21 Wind Tunnel with Documented Axial Flow. A wind tunnel facility
documented as meeting the provisions of sections 10.1.1 (velocity
pressure cross-check) and 10.1.2 (axial flow verification) using the
procedures described in these sections or alternative procedures
determined to be technically equivalent.
3.22 Yaw Angle. The angle between the axis of the stack or duct and
the yaw component of flow, i.e., the component of the total velocity
vector in a plane perpendicular to the traverse line at a particular
traverse point. (Figure 2F-1 illustrates the ``yaw plane.'') From the
standpoint of a tester facing a test port in a vertical stack, the yaw
component of flow is the vector of flow moving to the left or right from
the center of the stack as viewed by the tester. (This is sometimes
referred to as ``vortex flow,'' i.e., flow around the centerline of a
stack or duct.) The yaw angle is the angle described by this yaw
component of flow and the vertical axis of the stack. The algebraic sign
convention is illustrated in Figure 2F-2.
3.23 Yaw Nulling. A procedure in which a probe is rotated about its
axis in a stack or duct until a zero differential pressure reading
(``yaw null'') is obtained. When a 3-D probe is yaw-nulled, its impact
pressure port (P1) faces directly into the direction of flow
in the stack or duct and the differential pressure between pressure
ports P2 and P3 is zero.
4.0 Interferences [Reserved]
5.0 Safety
5.1 This test method may involve hazardous operations and the use of
hazardous materials or equipment. This method does not purport to
address all of the safety problems associated with its use. It is the
responsibility of the user to establish and implement appropriate safety
and health practices and to determine the applicability of regulatory
limitations before using this test method.
6.0 Equipment and Supplies
6.1 Three-dimensional Probes. The 3-D probes as specified in
subsections 6.1.1 through 6.1.3 below qualify for use based on
comprehensive wind tunnel and field studies involving both inter-and
intra-probe comparisons by multiple test teams. Other types of probes
shall not be used unless approved by the Administrator. Each 3-D probe
shall have a unique identification number or code permanently marked on
the main probe sheath. The minimum recommended diameter of the sensing
head of any probe used under this method is 2.5 cm (1 in.). Each probe
shall be calibrated prior to use according to the procedures in section
10. Manufacturer-supplied calibration data shall be used as example
information only, except when the manufacturer calibrates the 3-D probe
as specified in section 10 and provides complete documentation.
6.1.1 Five-hole prism-shaped probe. This type of probe consists of
five pressure taps in the flat facets of a prism-shaped sensing head.
The pressure taps are numbered 1 through 5, with the pressures measured
at each hole referred to as P1, P2, P3,
P4, and P5, respectively. Figure 2F-3 is an
illustration of the placement of pressure taps on a commonly available
five-hole prism-shaped probe, the 2.5-cm (1-in.) DAT probe. (Note:
Mention of trade names or specific products does not constitute
endorsement by the U.S. Environmental Protection Agency.) The numbering
arrangement for the prism-shaped sensing head presented in Figure 2F-3
shall be followed for correct operation of the probe. A brief
description of the probe measurements involved is as follows: the
differential pressure P2-P3 is used to yaw null
the probe and determine the yaw angle; the differential pressure
P4-P5 is a function of pitch angle; and the
differential pressure P1-P2 is a function of total
velocity.
6.1.2 Five-hole spherical probe. This type of probe consists of five
pressure taps in a spherical sensing head. As with the prism-shaped
probe, the pressure taps are numbered 1 through 5, with the pressures
measured at each hole referred to as P1, P2,
P3, P4, and P5, respectively. However,
the P4 and P5 pressure taps are in the reverse
location
[[Page 49]]
from their respective positions on the prism-shaped probe head. The
differential pressure P2-P3 is used to yaw null
the probe and determine the yaw angle; the differential pressure
P4-P5 is a function of pitch angle; and the
differential pressure P1-P2 is a function of total
velocity. A diagram of a typical spherical probe sensing head is
presented in Figure 2F-4. Typical probe dimensions are indicated in the
illustration.
6.1.3 A manual 3-D probe refers to a five-hole prism-shaped or
spherical probe that is positioned at individual traverse points and yaw
nulled manually by an operator. An automated 3-D probe refers to a
system that uses a computer-controlled motorized mechanism to position
the five-hole prism-shaped or spherical head at individual traverse
points and perform yaw angle determinations.
6.1.4 Other three-dimensional probes. [Reserved]
6.1.5 Probe sheath. The probe shaft shall include an outer sheath
to: (1) provide a surface for inscribing a permanent reference scribe
line, (2) accommodate attachment of an angle-measuring device to the
probe shaft, and (3) facilitate precise rotational movement of the probe
for determining yaw angles. The sheath shall be rigidly attached to the
probe assembly and shall enclose all pressure lines from the probe head
to the farthest position away from the probe head where an angle-
measuring device may be attached during use in the field. The sheath of
the fully assembled probe shall be sufficiently rigid and straight at
all rotational positions such that, when one end of the probe shaft is
held in a horizontal position, the fully extended probe meets the
horizontal straightness specifications indicated in section 8.2 below.
6.1.6 Scribe lines.
6.1.6.1 Reference scribe line. A permanent line, no greater than 1.6
mm (1/16 in.) in width, shall be inscribed on each manual probe that
will be used to determine yaw angles of flow. This line shall be placed
on the main probe sheath in accordance with the procedures described in
section 10.4 and is used as a reference position for installation of the
yaw angle-measuring device on the probe. At the discretion of the
tester, the scribe line may be a single line segment placed at a
particular position on the probe sheath (e.g., near the probe head),
multiple line segments placed at various locations along the length of
the probe sheath (e.g., at every position where a yaw angle-measuring
device may be mounted), or a single continuous line extending along the
full length of the probe sheath.
6.1.6.2 Scribe line on probe extensions. A permanent line may also
be inscribed on any probe extension that will be attached to the main
probe in performing field testing. This allows a yaw angle-measuring
device mounted on the extension to be readily aligned with the reference
scribe line on the main probe sheath.
6.1.6.3 Alignment specifications. This specification shall be met
separately, using the procedures in section 10.4.1, on the main probe
and on each probe extension. The rotational position of the scribe line
or scribe line segments on the main probe or any probe extension must
not vary by more than 2[deg]. That is, the difference between the
minimum and maximum of all of the rotational angles that are measured
along the full length of the main probe or the probe extension must not
exceed 2[deg].
6.1.7 Probe and system characteristics to ensure horizontal
stability.
6.1.7.1 For manual probes, it is recommended that the effective
length of the probe (coupled with a probe extension, if necessary) be at
least 0.9 m (3 ft.) longer than the farthest traverse point mark on the
probe shaft away from the probe head. The operator should maintain the
probe's horizontal stability when it is fully inserted into the stack or
duct. If a shorter probe is used, the probe should be inserted through a
bushing sleeve, similar to the one shown in Figure 2F-5, that is
installed on the test port; such a bushing shall fit snugly around the
probe and be secured to the stack or duct entry port in such a manner as
to maintain the probe's horizontal stability when fully inserted into
the stack or duct.
6.1.7.2 An automated system that includes an external probe casing
with a transport system shall have a mechanism for maintaining
horizontal stability comparable to that obtained by manual probes
following the provisions of this method. The automated probe assembly
shall also be constructed to maintain the alignment and position of the
pressure ports during sampling at each traverse point. The design of the
probe casing and transport system shall allow the probe to be removed
from the stack or duct and checked through direct physical measurement
for angular position and insertion depth.
6.1.8 The tubing that is used to connect the probe and the pressure-
measuring device should have an inside diameter of at least 3.2 mm (1/8
in.), to reduce the time required for pressure equilibration, and should
be as short as practicable.
6.2 Yaw Angle-measuring Device. One of the following devices shall
be used for measurement of the yaw angle of flow.
6.2.1 Digital inclinometer. This refers to a digital device capable
of measuring and displaying the rotational position of the probe to
within 1[deg]. The device shall be able to be
locked into position on the probe sheath or probe extension, so that it
indicates the probe's rotational position throughout the test. A
rotational position collar block that can be attached to the probe
sheath (similar
[[Page 50]]
to the collar shown in Figure 2F-6) may be required to lock the digital
inclinometer into position on the probe sheath.
6.2.2 Protractor wheel and pointer assembly. This apparatus, similar
to that shown in Figure 2F-7, consists of the following components.
6.2.2.1 A protractor wheel that can be attached to a port opening
and set in a fixed rotational position to indicate the yaw angle
position of the probe's scribe line relative to the longitudinal axis of
the stack or duct. The protractor wheel must have a measurement ring on
its face that is no less than 17.8 cm (7 in.) in diameter, shall be able
to be rotated to any angle and then locked into position on the stack or
duct port, and shall indicate angles to a resolution of 1[deg].
6.2.2.2 A pointer assembly that includes an indicator needle mounted
on a collar that can slide over the probe sheath and be locked into a
fixed rotational position on the probe sheath. The pointer needle shall
be of sufficient length, rigidity, and sharpness to allow the tester to
determine the probe's angular position to within 1[deg] from the
markings on the protractor wheel. Corresponding to the position of the
pointer, the collar must have a scribe line to be used in aligning the
pointer with the scribe line on the probe sheath.
6.2.3 Other yaw angle-measuring devices. Other angle-measuring
devices with a manufacturer's specified precision of 1[deg] or better
may be used, if approved by the Administrator.
6.3 Probe Supports and Stabilization Devices. When probes are used
for determining flow angles, the probe head should be kept in a stable
horizontal position. For probes longer than 3.0 m (10 ft.), the section
of the probe that extends outside the test port shall be secured. Three
alternative devices are suggested for maintaining the horizontal
position and stability of the probe shaft during flow angle
determinations and velocity pressure measurements: (1) Monorails
installed above each port, (2) probe stands on which the probe shaft may
be rested, or (3) bushing sleeves of sufficient length secured to the
test ports to maintain probes in a horizontal position. Comparable
provisions shall be made to ensure that automated systems maintain the
horizontal position of the probe in the stack or duct. The physical
characteristics of each test platform may dictate the most suitable type
of stabilization device. Thus, the choice of a specific stabilization
device is left to the judgment of the testers.
6.4 Differential Pressure Gauges. The pressure ([Delta]P) measuring
devices used during wind tunnel calibrations and field testing shall be
either electronic manometers (e.g., pressure transducers), fluid
manometers, or mechanical pressure gauges (e.g.,
Magnehelic[Delta] gauges). Use of electronic manometers is
recommended. Under low velocity conditions, use of electronic manometers
may be necessary to obtain acceptable measurements.
6.4.1 Differential pressure-measuring device. This refers to a
device capable of measuring pressure differentials and having a
readability of 1 percent of full scale. The device
shall be capable of accurately measuring the maximum expected pressure
differential. Such devices are used to determine the following pressure
measurements: velocity pressure, static pressure, yaw-null pressure, and
pitch-angle pressure. For an inclined-vertical manometer, the
readability specification of 1 percent shall be
met separately using the respective full-scale upper limits of the
inclined and vertical portions of the scales. To the extent practicable,
the device shall be selected such that most of the pressure readings are
between 10 and 90 percent of the device's full-scale measurement range
(as defined in section 3.5). Typical velocity pressure (P1-
P2) ranges for both the prism-shaped probe and the spherical
probe are 0 to 1.3 cm H2O (0 to 0.5 in. H2O), 0 to
5.1 cm H2O (0 to 2 in. H2O), and 0 to 12.7 cm
H2O (0 to 5 in. H2O). The pitch angle
(P4-P5) pressure range is typically -6.4 to + 6.4
mm H2O (-0.25 to + 0.25 in. H2O) or -12.7 to +
12.7 mm H2O (-0.5 to + 0.5 in. H2O) for the prism-
shaped probe, and -12.7 to + 12.7 mm H2O (-0.5 to + 0.5 in.
H2O) or -5.1 to + 5.1 cm H2O (-2 to + 2 in.
H2O) for the spherical probe. The pressure range for the yaw
null (P2-P3) readings is typically -12.7 to + 12.7
mm H2O (-0.5 to + 0.5 in. H2O) for both probe
types. In addition, pressure-measuring devices should be selected such
that the zero does not drift by more than 5 percent of the average
expected pressure readings to be encountered during the field test. This
is particularly important under low pressure conditions.
6.4.2 Gauge used for yaw nulling. The differential pressure-
measuring device chosen for yaw nulling the probe during the wind tunnel
calibrations and field testing shall be bi-directional, i.e., capable of
reading both positive and negative differential pressures. If a
mechanical, bi-directional pressure gauge is chosen, it shall have a
full-scale range no greater than 2.6 cm H2O (1 in.
H2O) [i.e., -1.3 to + 1.3 cm H2O (-0.5 in. to +
0.5 in.)].
6.4.3 Devices for calibrating differential pressure-measuring
devices. A precision manometer (e.g., a U-tube, inclined, or inclined-
vertical manometer, or micromanometer) or NIST (National Institute of
Standards and Technology) traceable pressure source shall be used for
calibrating differential pressure-measuring devices. The device shall be
maintained under laboratory conditions or in a similar protected
environment (e.g., a climate-controlled trailer). It shall not be used
in field tests. The precision manometer shall have a scale gradation of
0.3 mm H2O (0.01 in. H2O), or less, in the range
of 0 to 5.1 cm H2O
[[Page 51]]
(0 to 2 in. H2O) and 2.5 mm H2O (0.1 in.
H2O), or less, in the range of 5.1 to 25.4 cm H2O
(2 to 10 in. H2O). The manometer shall have manufacturer's
documentation that it meets an accuracy specification of at least 0.5
percent of full scale. The NIST-traceable pressure source shall be
recertified annually.
6.4.4 Devices used for post-test calibration check. A precision
manometer meeting the specifications in section 6.4.3, a pressure-
measuring device or pressure source with a documented calibration
traceable to NIST, or an equivalent device approved by the Administrator
shall be used for the post-test calibration check. The pressure-
measuring device shall have a readability equivalent to or greater than
the tested device. The pressure source shall be capable of generating
pressures between 50 and 90 percent of the range of the tested device
and known to within 1 percent of the full scale of
the tested device. The pressure source shall be recertified annually.
6.5 Data Display and Capture Devices. Electronic manometers (if
used) shall be coupled with a data display device (such as a digital
panel meter, personal computer display, or strip chart) that allows the
tester to observe and validate the pressure measurements taken during
testing. They shall also be connected to a data recorder (such as a data
logger or a personal computer with data capture software) that has the
ability to compute and retain the appropriate average value at each
traverse point, identified by collection time and traverse point.
6.6 Temperature Gauges. For field tests, a thermocouple or
resistance temperature detector (RTD) capable of measuring temperature
to within 3 [deg]C (5
[deg]F) of the stack or duct temperature shall be used. The thermocouple
shall be attached to the probe such that the sensor tip does not touch
any metal and is located on the opposite side of the probe head from the
pressure ports so as not to interfere with the gas flow around the probe
head. The position of the thermocouple relative to the pressure port
face openings shall be in the same configuration as used for the probe
calibrations in the wind tunnel. Temperature gauges used for wind tunnel
calibrations shall be capable of measuring temperature to within 0.6 [deg]C (1 [deg]F) of the
temperature of the flowing gas stream in the wind tunnel.
6.7 Stack or Duct Static Pressure Measurement. The pressure-
measuring device used with the probe shall be as specified in section
6.4 of this method. The static tap of a standard (Prandtl type) pitot
tube or one leg of a Type S pitot tube with the face opening planes
positioned parallel to the gas flow may be used for this measurement.
Also acceptable is the pressure differential reading of P1-
Pbar from a five-hole prism-shaped probe (e.g., Type DA or
DAT probe) with the P1 pressure port face opening positioned
parallel to the gas flow in the same manner as the Type S probe.
However, the spherical probe, as specified in section 6.1.2, is unable
to provide this measurement and shall not be used to take static
pressure measurements. Static pressure measurement is further described
in section 8.11.
6.8 Barometer. Same as Method 2, section 2.5.
6.9 Gas Density Determination Equipment. Method 3 or 3A shall be
used to determine the dry molecular weight of the stack gas. Method 4
shall be used for moisture content determination and computation of
stack gas wet molecular weight. Other methods may be used, if approved
by the Administrator.
6.10 Calibration Pitot Tube. Same as Method 2, section 2.7.
6.11 Wind Tunnel for Probe Calibration. Wind tunnels used to
calibrate velocity probes must meet the following design specifications.
6.11.1 Test section cross-sectional area. The flowing gas stream
shall be confined within a circular, rectangular, or elliptical duct.
The cross-sectional area of the tunnel must be large enough to ensure
fully developed flow in the presence of both the calibration pitot tube
and the tested probe. The calibration site, or ``test section,'' of the
wind tunnel shall have a minimum diameter of 30.5 cm (12 in.) for
circular or elliptical duct cross-sections or a minimum width of 30.5 cm
(12 in.) on the shorter side for rectangular cross-sections. Wind
tunnels shall meet the probe blockage provisions of this section and the
qualification requirements prescribed in section 10.1. The projected
area of the portion of the probe head, shaft, and attached devices
inside the wind tunnel during calibration shall represent no more than 4
percent of the cross-sectional area of the tunnel. The projected area
shall include the combined area of the calibration pitot tube and the
tested probe if both probes are placed simultaneously in the same cross-
sectional plane in the wind tunnel, or the larger projected area of the
two probes if they are placed alternately in the wind tunnel.
6.11.2 Velocity range and stability. The wind tunnel should be
capable of maintaining velocities between 6.1 m/sec and 30.5 m/sec (20
ft/sec and 100 ft/sec). The wind tunnel shall produce fully developed
flow patterns that are stable and parallel to the axis of the duct in
the test section.
6.11.3 Flow profile at the calibration location. The wind tunnel
shall provide axial flow within the test section calibration location
(as defined in section 3.20). Yaw and pitch angles in the calibration
location shall be within 3[deg] of 0[deg]. The
procedure for determining that this requirement has been met is
described in section 10.1.2.
6.11.4 Entry ports in the wind tunnel test section.
[[Page 52]]
6.11.4.1 Port for tested probe. A port shall be constructed for the
tested probe. The port should have an elongated slot parallel to the
axis of the duct at the test section. The elongated slot should be of
sufficient length to allow attaining all the pitch angles at which the
probe will be calibrated for use in the field. To facilitate alignment
of the probe during calibration, the test section should include a
window constructed of a transparent material to allow the tested probe
to be viewed. This port shall be located to allow the head of the tested
probe to be positioned within the calibration location (as defined in
section 3.20) at all pitch angle settings.
6.11.4.2 Port for verification of axial flow. Depending on the
equipment selected to conduct the axial flow verification prescribed in
section 10.1.2, a second port, located 90[deg] from the entry port for
the tested probe, may be needed to allow verification that the gas flow
is parallel to the central axis of the test section. This port should be
located and constructed so as to allow one of the probes described in
section 10.1.2.2 to access the same test point(s) that are accessible
from the port described in section 6.11.4.1.
6.11.4.3 Port for calibration pitot tube. The calibration pitot tube
shall be used in the port for the tested probe or a separate entry port.
In either case, all measurements with the calibration pitot tube shall
be made at the same point within the wind tunnel over the course of a
probe calibration. The measurement point for the calibration pitot tube
shall meet the same specifications for distance from the wall and for
axial flow as described in section 3.20 for the wind tunnel calibration
location.
6.11.5 Pitch angle protractor plate. A protractor plate shall be
attached directly under the port used with the tested probe and set in a
fixed position to indicate the pitch angle position of the probe
relative to the longitudinal axis of the wind tunnel duct (similar to
Figure 2F-8). The protractor plate shall indicate angles in 5[deg]
increments with a minimum resolution of 2[deg].
The tested probe shall be able to be locked into position at the desired
pitch angle delineated on the protractor. The probe head position shall
be maintained within the calibration location (as defined in section
3.20) in the test section of the wind tunnel during all tests across the
range of pitch angles.
7.0 Reagents and Standards [Reserved]
8.0 Sample Collection and Analysis
8.1 Equipment Inspection and Set-Up
8.1.1 All probes, differential pressure-measuring devices, yaw
angle-measuring devices, thermocouples, and barometers shall have a
current, valid calibration before being used in a field test. (See
sections 10.3.3, 10.3.4, and 10.5 through10.10 for the applicable
calibration requirements.)
8.1.2 Before each field use of a 3-D probe, perform a visual
inspection to verify the physical condition of the probe head according
to the procedures in section 10.2. Record the inspection results on a
form similar to Table 2F-1. If there is visible damage to the 3-D probe,
the probe shall not be used until it is recalibrated.
8.1.3 After verifying that the physical condition of the probe head
is acceptable, set up the apparatus using lengths of flexible tubing
that are as short as practicable. Surge tanks installed between the
probe and pressure-measuring device may be used to dampen pressure
fluctuations provided that an adequate measurement response time (see
section 8.8) is maintained.
8.2 Horizontal Straightness Check. A horizontal straightness check
shall be performed before the start of each field test, except as
otherwise specified in this section. Secure the fully assembled probe
(including the probe head and all probe shaft extensions) in a
horizontal position using a stationary support at a point along the
probe shaft approximating the location of the stack or duct entry port
when the probe is sampling at the farthest traverse point from the stack
or duct wall. The probe shall be rotated to detect bends. Use an angle-
measuring device or trigonometry to determine the bend or sag between
the probe head and the secured end. (See Figure 2F-9.) Probes that are
bent or sag by more than 5[deg] shall not be used. Although this check
does not apply when the probe is used for a vertical traverse, care
should be taken to avoid the use of bent probes when conducting vertical
traverses. If the probe is constructed of a rigid steel material and
consists of a main probe without probe extensions, this check need only
be performed before the initial field use of the probe, when the probe
is recalibrated, when a change is made to the design or material of the
probe assembly, and when the probe becomes bent. With such probes, a
visual inspection shall be made of the fully assembled probe before each
field test to determine if a bend is visible. The probe shall be rotated
to detect bends. The inspection results shall be documented in the field
test report. If a bend in the probe is visible, the horizontal
straightness check shall be performed before the probe is used.
8.3 Rotational Position Check. Before each field test, and each time
an extension is added to the probe during a field test, a rotational
position check shall be performed on all manually operated probes
(except as noted in section 8.3.5, below) to ensure that, throughout
testing, the angle-measuring device is either: aligned to within 1[deg] of the rotational position of the reference
scribe line; or is affixed to the probe such that the rotational offset
of the device from the reference scribe line is known to within 1[deg]. This check shall consist of direct measurements
of the
[[Page 53]]
rotational positions of the reference scribe line and angle-measuring
device sufficient to verify that these specifications are met. Annex A
in section 18 of this method gives recommended procedures for performing
the rotational position check, and Table 2F-2 gives an example data
form. Procedures other than those recommended in Annex A in section 18
may be used, provided they demonstrate whether the alignment
specification is met and are explained in detail in the field test
report.
8.3.1 Angle-measuring device rotational offset. The tester shall
maintain a record of the angle-measuring device rotational offset,
RADO, as defined in section 3.1. Note that RADO is
assigned a value of 0[deg] when the angle-measuring device is aligned to
within 1[deg] of the rotational position of the
reference scribe line. The RADO shall be used to determine
the yaw angle of flow in accordance with section 8.9.4.
8.3.2 Sign of angle-measuring device rotational offset. The sign of
RADO is positive when the angle-measuring device (as viewed
from the ``tail'' end of the probe) is positioned in a clockwise
direction from the reference scribe line and negative when the device is
positioned in a counterclockwise direction from the reference scribe
line.
8.3.3 Angle-measuring devices that can be independently adjusted
(e.g., by means of a set screw), after being locked into position on the
probe sheath, may be used. However, the RADO must also take
into account this adjustment.
8.3.4 Post-test check. If probe extensions remain attached to the
main probe throughout the field test, the rotational position check
shall be repeated, at a minimum, at the completion of the field test to
ensure that the angle-measuring device has remained within 2[deg] of its rotational position established prior to
testing. At the discretion of the tester, additional checks may be
conducted after completion of testing at any sample port or after any
test run. If the 2[deg] specification is not met,
all measurements made since the last successful rotational position
check must be repeated. section 18.1.1.3 of Annex A provides an example
procedure for performing the post-test check.
8.3.5 Exceptions.
8.3.5.1 A rotational position check need not be performed if, for
measurements taken at all velocity traverse points, the yaw angle-
measuring device is mounted and aligned directly on the reference scribe
line specified in sections 6.1.6.1 and 6.1.6.3 and no independent
adjustments, as described in section 8.3.3, are made to the device's
rotational position.
8.3.5.2 If extensions are detached and re-attached to the probe
during a field test, a rotational position check need only be performed
the first time an extension is added to the probe, rather than each time
the extension is re-attached, if the probe extension is designed to be
locked into a mechanically fixed rotational position (e.g., through use
of interlocking grooves) that can re-establish the initial rotational
position to within 1[deg].
8.4 Leak Checks. A pre-test leak check shall be conducted before
each field test. A post-test check shall be performed at the end of the
field test, but additional leak checks may be conducted after any test
run or group of test runs. The post-test check may also serve as the
pre-test check for the next group of test runs. If any leak check is
failed, all runs since the last passed leak check are invalid. While
performing the leak check procedures, also check each pressure device's
responsiveness to the changes in pressure.
8.4.1 To perform the leak check, pressurize the probe's
P1 pressure port until at least 7.6 cm H2O (3 in.
H2O) pressure, or a pressure corresponding to approximately
75 percent of the pressure-measuring device's measurement scale,
whichever is less, registers on the device; then, close off the pressure
port. The pressure shall remain stable [2.5 mm
H2O (0.10 in. H2O)] for at
least 15 seconds. Check the P2, P3, P4,
and P5 pressure ports in the same fashion. Other leak-check
procedures may be used, if approved by the Administrator.
8.5 Zeroing the Differential Pressure-measuring Device. Zero each
differential pressure-measuring device, including the device used for
yaw nulling, before each field test. At a minimum, check the zero after
each field test. A zero check may also be performed after any test run
or group of test runs. For fluid manometers and mechanical pressure
gauges (e.g., Magnehelic[Delta] gauges), the zero reading
shall not deviate from zero by more than 0.8 mm
H2O (0.03 in. H2O) or one
minor scale division, whichever is greater, between checks. For
electronic manometers, the zero reading shall not deviate from zero
between checks by more than: 0.3 mm H2O
(0.01 in. H2O), for full scales less
than or equal to 5.1 cm H2O (2.0 in. H2O); or
0.8 mm H2O (0.03
in. H2O), for full scales greater than 5.1 cm H2O
(2.0 in. H2O). (Note: If negative zero drift is not directly
readable, estimate the reading based on the position of the gauge oil in
the manometer or of the needle on the pressure gauge.) In addition, for
all pressure-measuring devices except those used exclusively for yaw
nulling, the zero reading shall not deviate from zero by more than 5
percent of the average measured differential pressure at any distinct
process condition or load level. If any zero check is failed at a
specific process condition or load level, all runs conducted at that
process condition or load level since the last passed zero check are
invalid.
8.6 Traverse Point Verification. The number and location of the
traverse points shall be selected based on Method 1 guidelines.
[[Page 54]]
The stack or duct diameter and port nipple lengths, including any
extension of the port nipples into stack or duct, shall be verified the
first time the test is performed; retain and use this information for
subsequent field tests, updating it as required. Physically measure the
stack or duct dimensions or use a calibrated laser device; do not use
engineering drawings of the stack or duct. The probe length necessary to
reach each traverse point shall be recorded to within 6.4 mm (1/4 in.) and, for manual
probes, marked on the probe sheath. In determining these lengths, the
tester shall take into account both the distance that the port flange
projects outside of the stack and the depth that any port nipple extends
into the gas stream. The resulting point positions shall reflect the
true distances from the inside wall of the stack or duct, so that when
the tester aligns any of the markings with the outside face of the stack
port, the probe's impact port shall be located at the appropriate
distance from the inside wall for the respective Method 1 traverse
point. Before beginning testing at a particular location, an out-of-
stack or duct verification shall be performed on each probe that will be
used to ensure that these position markings are correct. The distances
measured during the verification must agree with the previously
calculated distances to within 1/4 in. For manual
probes, the traverse point positions shall be verified by measuring the
distance of each mark from the probe's P1 pressure port. A
comparable out-of-stack test shall be performed on automated probe
systems. The probe shall be extended to each of the prescribed traverse
point positions. Then, the accuracy of the positioning for each traverse
point shall be verified by measuring the distance between the port
flange and the probe's P1 pressure port.
8.7 Probe Installation. Insert the probe into the test port. A solid
material shall be used to seal the port.
8.8 System Response Time. Determine the response time of the probe
measurement system. Insert and position the ``cold'' probe (at ambient
temperature and pressure) at any Method 1 traverse point. Read and
record the probe's P1-P2 differential pressure,
temperature, and elapsed time at 15-second intervals until stable
readings for both pressure and temperature are achieved. The response
time is the longer of these two elapsed times. Record the response time.
8.9 Sampling.
8.9.1 Yaw angle measurement protocol. With manual probes, yaw angle
measurements may be obtained in two alternative ways during the field
test, either by using a yaw angle-measuring device (e.g., digital
inclinometer) affixed to the probe, or using a protractor wheel and
pointer assembly. For horizontal traversing, either approach may be
used. For vertical traversing, i.e., when measuring from on top or into
the bottom of a horizontal duct, only the protractor wheel and pointer
assembly may be used. With automated probes, curve-fitting protocols may
be used to obtain yaw-angle measurements.
8.9.1.1 If a yaw angle-measuring device affixed to the probe is to
be used, lock the device on the probe sheath, aligning it either on the
reference scribe line or in the rotational offset position established
under section 8.3.1.
8.9.1.2 If a protractor wheel and pointer assembly is to be used,
follow the procedures in Annex B of this method.
8.9.1.3 Other yaw angle-determination procedures. If approved by the
Administrator, other procedures for determining yaw angle may be used,
provided that they are verified in a wind tunnel to be able to perform
the yaw angle calibration procedure as described in section 10.5.
8.9.2 Sampling strategy. At each traverse point, first yaw-null the
probe, as described in section 8.9.3, below. Then, with the probe
oriented into the direction of flow, measure and record the yaw angle,
the differential pressures and the temperature at the traverse point,
after stable readings are achieved, in accordance with sections 8.9.4
and 8.9.5. At the start of testing in each port (i.e., after a probe has
been inserted into the flue gas stream), allow at least the response
time to elapse before beginning to take measurements at the first
traverse point accessed from that port. Provided that the probe is not
removed from the flue gas stream, measurements may be taken at
subsequent traverse points accessed from the same test port without
waiting again for the response time to elapse.
8.9.3 Yaw-nulling procedure. In preparation for yaw angle
determination, the probe must first be yaw nulled. After positioning the
probe at the appropriate traverse point, perform the following
procedures.
8.9.3.1 Rotate the probe until a null differential pressure reading
(the difference in pressures across the P2 and P3
pressure ports is zero, i.e., P2 = P3) is
indicated by the yaw angle pressure gauge. Read and record the angle
displayed by the angle-measuring device.
8.9.3.2 Sign of the measured angle. The angle displayed on the
angle-measuring device is considered positive when the probe's impact
pressure port (as viewed from the ``tail'' end of the probe) is oriented
in a clockwise rotational position relative to the stack or duct axis
and is considered negative when the probe's impact pressure port is
oriented in a counterclockwise rotational position (see Figure 2F-10).
8.9.4 Yaw angle determination. After performing the yaw-nulling
procedure in section
[[Page 55]]
8.9.3, determine the yaw angle of flow according to one of the following
procedures. Special care must be observed to take into account the signs
of the recorded angle and all offsets.
8.9.4.1 Direct-reading. If all rotational offsets are zero or if the
angle-measuring device rotational offset (RADO) determined in
section 8.3 exactly compensates for the scribe line rotational offset
(RSLO) determined in section 10.5, then the magnitude of the
yaw angle is equal to the displayed angle-measuring device reading from
section 8.9.3.1. The algebraic sign of the yaw angle is determined in
accordance with section 8.9.3.2.
Note: Under certain circumstances (e.g., testing of horizontal
ducts), a 90[deg] adjustment to the angle-measuring device readings may
be necessary to obtain the correct yaw angles.
8.9.4.2 Compensation for rotational offsets during data reduction.
When the angle-measuring device rotational offset does not compensate
for reference scribe line rotational offset, the following procedure
shall be used to determine the yaw angle:
(a) Enter the reading indicated by the angle-measuring device from
section 8.9.3.1.
(b) Associate the proper algebraic sign from section 8.9.3.2 with
the reading in step (a).
(c) Subtract the reference scribe line rotational offset,
RSLO, from the reading in step (b).
(d) Subtract the angle-measuring device rotational offset,
RADO, if any, from the result obtained in step (c).
(e) The final result obtained in step (d) is the yaw angle of flow.
Note: It may be necessary to first apply a 90[deg] adjustment to the
reading in step (a), in order to obtain the correct yaw angle.
8.9.4.3 Record the yaw angle measurements on a form similar to Table
2F-3.
8.9.5 Velocity determination. Maintain the probe rotational position
established during the yaw angle determination. Then, begin recording
the pressure-measuring device readings for the impact pressure
(P1-P2) and pitch angle pressure (P4-
P5). These pressure measurements shall be taken over a
sampling period of sufficiently long duration to ensure representative
readings at each traverse point. If the pressure measurements are
determined from visual readings of the pressure device or display, allow
sufficient time to observe the pulsation in the readings to obtain a
sight-weighted average, which is then recorded manually. If an automated
data acquisition system (e.g., data logger, computer-based data
recorder, strip chart recorder) is used to record the pressure
measurements, obtain an integrated average of all pressure readings at
the traverse point. Stack or duct gas temperature measurements shall be
recorded, at a minimum, once at each traverse point. Record all
necessary data as shown in the example field data form (Table 2F-3).
8.9.6 Alignment check. For manually operated probes, after the
required yaw angle and differential pressure and temperature
measurements have been made at each traverse point, verify (e.g., by
visual inspection) that the yaw angle-measuring device has remained in
proper alignment with the reference scribe line or with the rotational
offset position established in section 8.3. If, for a particular
traverse point, the angle-measuring device is found to be in proper
alignment, proceed to the next traverse point; otherwise, re-align the
device and repeat the angle and differential pressure measurements at
the traverse point. In the course of a traverse, if a mark used to
properly align the angle-measuring device (e.g., as described in section
18.1.1.1) cannot be located, re-establish the alignment mark before
proceeding with the traverse.
8.10 Probe Plugging. Periodically check for plugging of the pressure
ports by observing the responses on pressure differential readouts.
Plugging causes erratic results or sluggish responses. Rotate the probe
to determine whether the readouts respond in the expected direction. If
plugging is detected, correct the problem and repeat the affected
measurements.
8.11 Static Pressure. Measure the static pressure in the stack or
duct using the equipment described in section 6.7.
8.11.1 If a Type DA or DAT probe is used for this measurement,
position the probe at or between any traverse point(s) and rotate the
probe until a null differential pressure reading is obtained at
P2-P3. Rotate the probe 90[deg]. Disconnect the
P2 pressure side of the probe and read the pressure
P1-Pbar and record as the static pressure. (Note:
The spherical probe, specified in section 6.1.2, is unable to provide
this measurement and shall not be used to take static pressure
measurements.)
8.11.2 If a Type S probe is used for this measurement, position the
probe at or between any traverse point(s) and rotate the probe until a
null differential pressure reading is obtained. Disconnect the tubing
from one of the pressure ports; read and record the [Delta]P. For
pressure devices with one-directional scales, if a deflection in the
positive direction is noted with the negative side disconnected, then
the static pressure is positive. Likewise, if a deflection in the
positive direction is noted with the positive side disconnected, then
the static pressure is negative.
8.12 Atmospheric Pressure. Determine the atmospheric pressure at the
sampling elevation during each test run following the procedure
described in section 2.5 of Method 2.
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8.13 Molecular Weight. Determine the stack gas dry molecular weight.
For combustion processes or processes that emit essentially
CO2, O2, CO, and N2, use Method 3 or
3A. For processes emitting essentially air, an analysis need not be
conducted; use a dry molecular weight of 29.0. Other methods may be
used, if approved by the Administrator.
8.14 Moisture. Determine the moisture content of the stack gas using
Method 4 or equivalent.
8.15 Data Recording and Calculations. Record all required data on a
form similar to Table 2F-3.
8.15.1 Selection of appropriate calibration curves. Choose the
appropriate pair of F1 and F2 versus pitch angle
calibration curves, created as described in section 10.6.
8.15.2 Pitch angle derivation. Use the appropriate calculation
procedures in section 12.2 to find the pitch angle ratios that are
applicable at each traverse point. Then, find the pitch angles
corresponding to these pitch angle ratios on the ``F1 versus
pitch angle'' curve for the probe.
8.15.3 Velocity calibration coefficient derivation. Use the pitch
angle obtained following the procedures described in section 8.15.2 to
find the corresponding velocity calibration coefficients from the
``F2 versus pitch angle'' calibration curve for the probe.
8.15.4 Calculations. Calculate the axial velocity at each traverse
point using the equations presented in section 12.2 to account for the
yaw and pitch angles of flow. Calculate the test run average stack gas
velocity by finding the arithmetic average of the point velocity results
in accordance with sections 12.3 and 12.4, and calculate the stack gas
volumetric flow rate in accordance with section 12.5 or 12.6, as
applicable.
9.0 Quality Control
9.1 Quality Control Activities. In conjunction with the yaw angle
determination and the pressure and temperature measurements specified in
section 8.9, the following quality control checks should be performed.
9.1.1 Range of the differential pressure gauge. In accordance with
the specifications in section 6.4, ensure that the proper differential
pressure gauge is being used for the range of [Delta]P values
encountered. If it is necessary to change to a more sensitive gauge,
replace the gauge with a gauge calibrated according to section 10.3.3,
perform the leak check described in section 8.4 and the zero check
described in section 8.5, and repeat the differential pressure and
temperature readings at each traverse point.
9.1.2 Horizontal stability check. For horizontal traverses of a
stack or duct, visually check that the probe shaft is maintained in a
horizontal position prior to taking a pressure reading. Periodically,
during a test run, the probe's horizontal stability should be verified
by placing a carpenter's level, a digital inclinometer, or other angle-
measuring device on the portion of the probe sheath that extends outside
of the test port. A comparable check should be performed by automated
systems.
10.0 Calibration
10.1 Wind Tunnel Qualification Checks. To qualify for use in
calibrating probes, a wind tunnel shall have the design features
specified in section 6.11 and satisfy the following qualification
criteria. The velocity pressure cross-check in section 10.1.1 and axial
flow verification in section 10.1.2 shall be performed before the
initial use of the wind tunnel and repeated immediately after any
alteration occurs in the wind tunnel's configuration, fans, interior
surfaces, straightening vanes, controls, or other properties that could
reasonably be expected to alter the flow pattern or velocity stability
in the tunnel. The owner or operator of a wind tunnel used to calibrate
probes according to this method shall maintain records documenting that
the wind tunnel meets the requirements of sections 10.1.1 and 10.1.2 and
shall provide these records to the Administrator upon request.
10.1.1 Velocity pressure cross-check. To verify that the wind tunnel
produces the same velocity at the tested probe head as at the
calibration pitot tube impact port, perform the following cross-check.
Take three differential pressure measurements at the fixed calibration
pitot tube location, using the calibration pitot tube specified in
section 6.10, and take three measurements with the calibration pitot
tube at the wind tunnel calibration location, as defined in section
3.20. Alternate the measurements between the two positions. Perform this
procedure at the lowest and highest velocity settings at which the
probes will be calibrated. Record the values on a form similar to Table
2F-4. At each velocity setting, the average velocity pressure obtained
at the wind tunnel calibration location shall be within 2 percent or 2.5 mm H2O (0.01 in.
H2O), whichever is less restrictive, of the average velocity
pressure obtained at the fixed calibration pitot tube location. This
comparative check shall be performed at 2.5-cm (1-in.), or smaller,
intervals across the full length, width, and depth (if applicable) of
the wind tunnel calibration location. If the criteria are not met at
every tested point, the wind tunnel calibration location must be
redefined, so that acceptable results are obtained at every point.
Include the results of the velocity pressure cross-check in the
calibration data section of the field test report. (See section 16.1.4.)
10.1.2 Axial flow verification. The following procedures shall be
performed to demonstrate that there is fully developed axial flow within
the calibration location and at
[[Page 57]]
the calibration pitot tube location. Two testing options are available
to conduct this check.
10.1.2.1 Using a calibrated 3-D probe. A 3-D probe that has been
previously calibrated in a wind tunnel with documented axial flow (as
defined in section 3.21) may be used to conduct this check. Insert the
calibrated 3-D probe into the wind tunnel test section using the tested
probe port. Following the procedures in sections 8.9 and 12.2 of this
method, determine the yaw and pitch angles at all the point(s) in the
test section where the velocity pressure cross-check, as specified in
section 10.1.1, is performed. This includes all the points in the
calibration location and the point where the calibration pitot tube will
be located. Determine the yaw and pitch angles at each point. Repeat
these measurements at the highest and lowest velocities at which the
probes will be calibrated. Record the values on a form similar to Table
2F-5. Each measured yaw and pitch angle shall be within 3[deg] of 0[deg]. Exceeding the limits indicates
unacceptable flow in the test section. Until the problem is corrected
and acceptable flow is verified by repetition of this procedure, the
wind tunnel shall not be used for calibration of probes. Include the
results of the axial flow verification in the calibration data section
of the field test report. (See section 16.1.4.)
10.1.2.2 Using alternative probes. Axial flow verification may be
performed using an uncalibrated prism-shaped 3-D probe (e.g., DA or DAT
probe) or an uncalibrated wedge probe. (Figure 2F-11 illustrates a
typical wedge probe.) This approach requires use of two ports: the
tested probe port and a second port located 90[deg] from the tested
probe port. Each port shall provide access to all the points within the
wind tunnel test section where the velocity pressure cross-check, as
specified in section 10.1.1, is conducted. The probe setup shall include
establishing a reference yaw-null position on the probe sheath to serve
as the location for installing the angle-measuring device. Physical
design features of the DA, DAT, and wedge probes are relied on to
determine the reference position. For the DA or DAT probe, this
reference position can be determined by setting a digital inclinometer
on the flat facet where the P1 pressure port is located and
then identifying the rotational position on the probe sheath where a
second angle-measuring device would give the same angle reading. The
reference position on a wedge probe shaft can be determined either
geometrically or by placing a digital inclinometer on each side of the
wedge and rotating the probe until equivalent readings are obtained.
With the latter approach, the reference position is the rotational
position on the probe sheath where an angle-measuring device would give
a reading of 0[deg]. After installing the angle-measuring device in the
reference yaw-null position on the probe sheath, determine the yaw angle
from the tested port. Repeat this measurement using the 90[deg] offset
port, which provides the pitch angle of flow. Determine the yaw and
pitch angles at all the point(s) in the test section where the velocity
pressure cross-check, as specified in section 10.1.1, is performed. This
includes all the points in the wind tunnel calibration location and the
point where the calibration pitot tube will be located. Perform this
check at the highest and lowest velocities at which the probes will be
calibrated. Record the values on a form similar to Table 2F-5. Each
measured yaw and pitch angle shall be within 3[deg] of 0[deg]. Exceeding the limits indicates
unacceptable flow in the test section. Until the problem is corrected
and acceptable flow is verified by repetition of this procedure, the
wind tunnel shall not be used for calibration of probes. Include the
results in the probe calibration report.
10.1.3 Wind tunnel audits.
10.1.3.1 Procedure. Upon the request of the Administrator, the owner
or operator of a wind tunnel shall calibrate a 3-D audit probe in
accordance with the procedures described in sections 10.3 through 10.6.
The calibration shall be performed at two velocities and over a pitch
angle range that encompasses the velocities and pitch angles typically
used for this method at the facility. The resulting calibration data and
curves shall be submitted to the Agency in an audit test report. These
results shall be compared by the Agency to reference calibrations of the
audit probe at the same velocity and pitch angle settings obtained at
two different wind tunnels.
10.1.3.2 Acceptance criteria. The audited tunnel's calibration is
acceptable if all of the following conditions are satisfied at each
velocity and pitch setting for the reference calibration obtained from
at least one of the wind tunnels. For pitch angle settings between -
15[deg] and + 15[deg], no velocity calibration coefficient (i.e.,
F2) may differ from the corresponding reference value by more
than 3 percent. For pitch angle settings outside of this range (i.e.,
less than -15[deg] and greater than + 15[deg]), no velocity calibration
coefficient may differ by more than 5 percent from the corresponding
reference value. If the acceptance criteria are not met, the audited
wind tunnel shall not be used to calibrate probes for use under this
method until the problems are resolved and acceptable results are
obtained upon completion of a subsequent audit.
10.2 Probe Inspection. Before each calibration of a 3-D probe,
carefully examine the physical condition of the probe head. Particular
attention shall be paid to the edges of the pressure ports and the
surfaces surrounding these ports. Any dents, scratches, or asymmetries
on the edges of the pressure ports and any scratches or indentations on
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the surfaces surrounding the pressure ports shall be noted because of
the potential effect on the probe's pressure readings. If the probe has
been previously calibrated, compare the current condition of the probe's
pressure ports and surfaces to the results of the inspection performed
during the probe's most recent wind tunnel calibration. Record the
results of this inspection on a form and in diagrams similar to Table
2F-1. The information in Table 2F-1 will be used as the basis for
comparison during the probe head inspections performed before each
subsequent field use.
10.3 Pre-Calibration Procedures. Prior to calibration, a scribe line
shall have been placed on the probe in accordance with section 10.4. The
yaw angle and velocity calibration procedures shall not begin until the
pre-test requirements in sections 10.3.1 through 10.3.4 have been met.
10.3.1 Perform the horizontal straightness check described in
section 8.2 on the probe assembly that will be calibrated in the wind
tunnel.
10.3.2 Perform a leak check in accordance with section 8.4.
10.3.3 Except as noted in section 10.3.3.3, calibrate all
differential pressure-measuring devices to be used in the probe
calibrations, using the following procedures. At a minimum, calibrate
these devices on each day that probe calibrations are performed.
10.3.3.1 Procedure. Before each wind tunnel use, all differential
pressure-measuring devices shall be calibrated against the reference
device specified in section 6.4.3 using a common pressure source.
Perform the calibration at three reference pressures representing 30,
60, and 90 percent of the full-scale range of the pressure-measuring
device being calibrated. For an inclined-vertical manometer, perform
separate calibrations on the inclined and vertical portions of the
measurement scale, considering each portion of the scale to be a
separate full-scale range. [For example, for a manometer with a 0- to
2.5-cm H2O (0- to 1-in. H2O) inclined scale and a
2.5- to 12.7-cm H2O (1- to 5-in. H2O) vertical
scale, calibrate the inclined portion at 7.6, 15.2, and 22.9 mm
H2O (0.3, 0.6, and 0.9 in. H2O), and calibrate the
vertical portion at 3.8, 7.6, and 11.4 cm H2O (1.5, 3.0, and
4.5 in. H2O).] Alternatively, for the vertical portion of the
scale, use three evenly spaced reference pressures, one of which is
equal to or higher than the highest differential pressure expected in
field applications.
10.3.3.2 Acceptance criteria. At each pressure setting, the two
pressure readings made using the reference device and the pressure-
measuring device being calibrated shall agree to within 2 percent of full scale of the device being calibrated
or 0.5 mm H2O (0.02 in. H2O), whichever is less
restrictive. For an inclined-vertical manometer, these requirements
shall be met separately using the respective full-scale upper limits of
the inclined and vertical portions of the scale. Differential pressure-
measuring devices not meeting the 2 percent of full scale or 0.5 mm
H2O (0.02 in. H2O) calibration requirement shall
not be used.
10.3.3.3 Exceptions. Any precision manometer that meets the
specifications for a reference device in section 6.4.3 and that is not
used for field testing does not require calibration, but must be leveled
and zeroed before each wind tunnel use. Any pressure device used
exclusively for yaw nulling does not require calibration, but shall be
checked for responsiveness to rotation of the probe prior to each wind
tunnel use.
10.3.4 Calibrate digital inclinometers on each day of wind tunnel or
field testing (prior to beginning testing) using the following
procedures. Calibrate the inclinometer according to the manufacturer's
calibration procedures. In addition, use a triangular block (illustrated
in Figure 2F-12) with a known angle, [theta] independently determined
using a protractor or equivalent device, between two adjacent sides to
verify the inclinometer readings.
Note: If other angle-measuring devices meeting the provisions of
section 6.2.3 are used in place of a digital inclinometer, comparable
calibration procedures shall be performed on such devices.)
Secure the triangular block in a fixed position. Place the inclinometer
on one side of the block (side A) to measure the angle of inclination
(R1). Repeat this measurement on the adjacent side of the
block (side B) using the inclinometer to obtain a second angle reading
(R2). The difference of the sum of the two readings from
180[deg] (i.e., 180[deg] -R1 -R2) shall be within
2[deg] of the known angle, [Theta]
10.4 Placement of Reference Scribe Line. Prior to the first
calibration of a probe, a line shall be permanently inscribed on the
main probe sheath to serve as a reference mark for determining yaw
angles. Annex C in section 18 of this method gives a guideline for
placement of the reference scribe line.
10.4.1 This reference scribe line shall meet the specifications in
sections 6.1.6.1 and 6.1.6.3 of this method. To verify that the
alignment specification in section 6.1.6.3 is met, secure the probe in a
horizontal position and measure the rotational angle of each scribe line
and scribe line segment using an angle-measuring device that meets the
specifications in section 6.2.1 or 6.2.3. For any scribe line that is
longer than 30.5 cm (12 in.), check the line's rotational position at
30.5-cm (12-in.) intervals. For each line segment that is 30.5 cm (12
in.) or less in length, check the rotational position at the two
endpoints of the segment. To meet the alignment specification in section
6.1.6.3, the minimum and maximum of all of the rotational angles that
are measured along the full
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length of the main probe must not differ by more than 2[deg].
Note: A short reference scribe line segment [e.g., 15.2 cm (6 in.)
or less in length] meeting the alignment specifications in section
6.1.6.3 is fully acceptable under this method. See section 18.1.1.1 of
Annex A for an example of a probe marking procedure, suitable for use
with a short reference scribe line.
10.4.2 The scribe line should be placed on the probe first and then
its offset from the yaw-null position established (as specified in
section 10.5). The rotational position of the reference scribe line
relative to the yaw-null position of the probe, as determined by the yaw
angle calibration procedure in section 10.5, is defined as the reference
scribe line rotational offset, RSLO. The reference scribe
line rotational offset shall be recorded and retained as part of the
probe's calibration record.
10.4.3 Scribe line for automated probes. A scribe line may not be
necessary for an automated probe system if a reference rotational
position of the probe is built into the probe system design. For such
systems, a ``flat'' (or comparable, clearly identifiable physical
characteristic) should be provided on the probe casing or flange plate
to ensure that the reference position of the probe assembly remains in a
vertical or horizontal position. The rotational offset of the flat (or
comparable, clearly identifiable physical characteristic) needed to
orient the reference position of the probe assembly shall be recorded
and maintained as part of the automated probe system's specifications.
10.5 Yaw Angle Calibration Procedure. For each probe used to measure
yaw angles with this method, a calibration procedure shall be performed
in a wind tunnel meeting the specifications in section 10.1 to determine
the rotational position of the reference scribe line relative to the
probe's yaw-null position. This procedure shall be performed on the main
probe with all devices that will be attached to the main probe in the
field [such as thermocouples or resistance temperature detectors (RTDs)]
that may affect the flow around the probe head. Probe shaft extensions
that do not affect flow around the probe head need not be attached
during calibration. At a minimum, this procedure shall include the
following steps.
10.5.1 Align and lock the angle-measuring device on the reference
scribe line. If a marking procedure (such as that described in section
18.1.1.1) is used, align the angle-measuring device on a mark within
1[deg] of the rotational position of the reference
scribe line. Lock the angle-measuring device onto the probe sheath at
this position.
10.5.2 Zero the pressure-measuring device used for yaw nulling.
10.5.3 Insert the probe assembly into the wind tunnel through the
entry port, positioning the probe's impact port at the calibration
location. Check the responsiveness of the pressure-measurement device to
probe rotation, taking corrective action if the response is
unacceptable.
10.5.4 Ensure that the probe is in a horizontal position, using a
carpenter's level.
10.5.5 Rotate the probe either clockwise or counterclockwise until a
yaw null (P2 = P3) is obtained.
10.5.6 Use the reading displayed by the angle-measuring device at
the yaw-null position to determine the magnitude of the reference scribe
line rotational offset, RSLO, as defined in section 3.15.
Annex D in section 18 of this method provides a recommended procedure
for determining the magnitude of RSLO with a digital
inclinometer and a second procedure for determining the magnitude of
RSLO with a protractor wheel and pointer device. Table 2F-6
presents an example data form and Table 2F-7 is a look-up table with the
recommended procedure. Procedures other than those recommended in Annex
D in section 18 may be used, if they can determine RSLO to
within 1[deg] and are explained in detail in the
field test report. The algebraic sign of RSLO will either be
positive, if the rotational position of the reference scribe line (as
viewed from the ``tail'' end of the probe) is clockwise, or negative, if
counterclockwise with respect to the probe's yaw-null position. (This is
illustrated in Figure 2F-13.)
10.5.7 The steps in sections 10.5.3 through 10.5.6 shall be
performed twice at each of the velocities at which the probe will be
calibrated (in accordance with section 10.6). Record the values of
RSLO.
10.5.8 The average of all of the RSLO values shall be
documented as the reference scribe line rotational offset for the probe.
10.5.9 Use of reference scribe line offset. The reference scribe
line rotational offset shall be used to determine the yaw angle of flow
in accordance with section 8.9.4.
10.6 Pitch Angle and Velocity Pressure Calibrations. Use the
procedures in sections 10.6.1 through 10.6.16 to generate an appropriate
set (or sets) of pitch angle and velocity pressure calibration curves
for each probe. The calibration procedure shall be performed on the main
probe and all devices that will be attached to the main probe in the
field (e.g., thermocouple or RTDs) that may affect the flow around the
probe head. Probe shaft extensions that do not affect flow around the
probe head need not be attached during calibration. (Note: If a sampling
nozzle is part of the assembly, a wind tunnel demonstration shall be
performed that shows the probe's ability to measure velocity and yaw
null is not impaired when the nozzle is drawing a sample.) The
calibration
[[Page 60]]
procedure involves generating two calibration curves, F1
versus pitch angle and F2 versus pitch angle. To generate
these two curves, F1 and F2 shall be derived using
Equations 2F-1 and 2F-2, below. Table 2F-8 provides an example wind
tunnel calibration data sheet, used to log the measurements needed to
derive these two calibration curves.
10.6.1 Calibration velocities. The tester may calibrate the probe at
two nominal wind tunnel velocity settings of 18.3 m/sec and 27.4 m/sec
(60 ft/sec and 90 ft/sec) and average the results of these calibrations,
as described in section 10.6.16.1, in order to generate a set of
calibration curves. If this option is selected, this single set of
calibration curves may be used for all field applications over the
entire velocity range allowed by the method. Alternatively, the tester
may customize the probe calibration for a particular field test
application (or for a series of applications), based on the expected
average velocity(ies) at the test site(s). If this option is selected,
generate each set of calibration curves by calibrating the probe at two
nominal wind tunnel velocity settings, at least one of which is greater
than or equal to the expected average velocity(ies) for the field
application(s), and average the results as described in section
10.6.16.1. Whichever calibration option is selected, the probe
calibration coefficients (F2 values) obtained at the two
nominal calibration velocities shall, for the same pitch angle setting,
meet the conditions specified in section 10.6.16.
10.6.2 Pitch angle calibration curve (F1 versus pitch
angle). The pitch angle calibration involves generating a calibration
curve of calculated F1 values versus tested pitch angles,
where F1 is the ratio of the pitch pressure to the velocity
pressure, i.e.,
[GRAPHIC] [TIFF OMITTED] TR14MY99.049
See Figure 2F-14 for an example F1 versus pitch angle
calibration curve.
10.6.3 Velocity calibration curve (F2 versus pitch
angle). The velocity calibration involves generating a calibration curve
of the 3-D probe's F2 coefficient against the tested pitch
angles, where
[GRAPHIC] [TIFF OMITTED] TR14MY99.050
and
Cp = calibration pitot tube coefficient, and
[Delta]Pstd = velocity pressure from the calibration pitot
tube.
See Figure 2F-15 for an example F2 versus pitch angle
calibration curve.
10.6.4 Connect the tested probe and calibration pitot probe to their
respective pressure-measuring devices. Zero the pressure-measuring
devices. Inspect and leak-check all pitot lines; repair or replace, if
necessary. Turn on the fan, and allow the wind tunnel air flow to
stabilize at the first of the two selected nominal velocity settings.
10.6.5 Position the calibration pitot tube at its measurement
location (determined as outlined in section 6.11.4.3), and align the
tube so that its tip is pointed directly into the flow. Ensure that the
entry port surrounding the tube is properly sealed. The calibration
pitot tube may either remain in the wind tunnel throughout the
calibration, or be removed from the wind tunnel while measurements are
taken with the probe being calibrated.
10.6.6 Set up the pitch protractor plate on the tested probe's entry
port to establish the pitch angle positions of the probe to within
2[deg].
10.6.7 Check the zero setting of each pressure-measuring device.
10.6.8 Insert the tested probe into the wind tunnel and align it so
that its P1 pressure port is pointed directly into the flow
and is positioned within the calibration location (as defined in section
3.20). Secure the probe at the 0[deg] pitch angle position. Ensure that
the entry port surrounding the probe is properly sealed.
10.6.9 Read the differential pressure from the calibration pitot
tube ([Delta]Pstd), and record its value. Read the barometric
pressure to within 2.5 mm Hg (0.1 in. Hg) and the temperature in the wind tunnel to
within 0.6 [deg]C (1 [deg]F). Record these values on a data form similar
to Table 2F-8.
10.6.10 After the tested probe's differential pressure gauges have
had sufficient time to stabilize, yaw null the probe, then obtain
differential pressure readings for (P1-P2) and
(P4-P5). Record the yaw angle and differential
pressure readings. After taking these readings, ensure that the tested
probe has remained at the yaw-null position.
10.6.11 Either take paired differential pressure measurements with
both the calibration pitot tube and tested probe (according to sections
10.6.9 and 10.6.10) or take readings only with the tested probe
(according to section 10.6.10) in 5[deg] increments over the pitch-angle
range for which the probe is to be calibrated. The calibration pitch-
angle range shall be symmetric around 0[deg] and shall exceed the
largest pitch angle expected in the field by 5[deg]. At a minimum,
probes shall be calibrated over the range of -15[deg] to + 15[deg]. If
paired calibration pitot tube and tested probe measurements are not
taken at each pitch angle setting, the differential pressure from the
calibration pitot tube shall be read, at a minimum, before taking the
tested probe's differential pressure reading at the first pitch angle
setting and after taking the tested probe's differential pressure
readings at the last pitch angle setting in each replicate.
[[Page 61]]
10.6.12 Perform a second replicate of the procedures in sections
10.6.5 through 10.6.11 at the same nominal velocity setting.
10.6.13 For each replicate, calculate the F1 and
F2 values at each pitch angle. At each pitch angle, calculate
the percent difference between the two F2 values using
Equation 2F-3.
[GRAPHIC] [TIFF OMITTED] TR14MY99.051
If the percent difference is less than or equal to 2 percent,
calculate an average F1 value and an average F2
value at that pitch angle. If the percent difference is greater than 2
percent and less than or equal to 5 percent, perform a third repetition
at that angle and calculate an average F1 value and an
average F2 value using all three repetitions. If the percent
difference is greater than 5 percent, perform four additional
repetitions at that angle and calculate an average F1 value
and an average F2 value using all six repetitions. When
additional repetitions are required at any pitch angle, move the probe
by at least 5[deg] and then return to the specified pitch angle before
taking the next measurement. Record the average values on a form similar
to Table 2F-9.
10.6.14 Repeat the calibration procedures in sections 10.6.5 through
10.6.13 at the second selected nominal wind tunnel velocity setting.
10.6.15 Velocity drift check. The following check shall be
performed, except when paired calibration pitot tube and tested probe
pressure measurements are taken at each pitch angle setting. At each
velocity setting, calculate the percent difference between consecutive
differential pressure measurements made with the calibration pitot tube.
If a measurement differs from the previous measurement by more than 2
percent or 0.25 mm H2O (0.01 in. H2O), whichever
is less restrictive, the calibration data collected between these
calibration pitot tube measurements may not be used, and the
measurements shall be repeated.
10.6.16 Compare the averaged F2 coefficients obtained
from the calibrations at the two selected nominal velocities, as
follows. At each pitch angle setting, use Equation 2F-3 to calculate the
difference between the corresponding average F2 values at the
two calibration velocities. At each pitch angle in the -15[deg] to +
15[deg] range, the percent difference between the average F2
values shall not exceed 3.0 percent. For pitch angles outside this range
(i.e., less than -15[deg]0 and greater than + 15[deg]), the percent
difference shall not exceed 5.0 percent.
10.6.16.1 If the applicable specification in section 10.6.16 is met
at each pitch angle setting, average the results obtained at the two
nominal calibration velocities to produce a calibration record of
F1 and F2 at each pitch angle tested. Record these
values on a form similar to Table 2F-9. From these values, generate one
calibration curve representing F1 versus pitch angle and a
second curve representing F2 versus pitch angle. Computer
spreadsheet programs may be used to graph the calibration data and to
develop polynomial equations that can be used to calculate pitch angles
and axial velocities.
10.6.16.2 If the applicable specification in section 10.6.16 is
exceeded at any pitch angle setting, the probe shall not be used unless:
(1) the calibration is repeated at that pitch angle and acceptable
results are obtained or (2) values of F1 and F2
are obtained at two nominal velocities for which the specifications in
section 10.6.16 are met across the entire pitch angle range.
10.7 Recalibration. Recalibrate the probe using the procedures in
section 10 either within 12 months of its first field use after its most
recent calibration or after 10 field tests (as defined in section 3.4),
whichever occurs later. In addition, whenever there is visible damage to
the 3-D head, the probe shall be recalibrated before it is used again.
10.8 Calibration of pressure-measuring devices used in field tests.
Before its initial use in a field test, calibrate each pressure-
measuring device (except those used exclusively for yaw nulling) using
the three-point calibration procedure described in section 10.3.3. The
device shall be recalibrated according to the procedure in section
10.3.3 no later than 90 days after its first field use following its
most recent calibration. At the discretion of the tester, more frequent
calibrations (e.g., after a field test) may be performed. No
adjustments, other than adjustments to the zero setting, shall be made
to the device between calibrations.
10.8.1 Post-test calibration check. A single-point calibration check
shall be performed on each pressure-measuring device after completion of
each field test. At the discretion of the tester, more frequent single-
point calibration checks (e.g., after one or more field test runs) may
be performed. It is recommended that the post-test check be performed
before leaving the field test site. The check shall be performed at a
pressure between 50 and 90 percent of full scale by taking a common
pressure reading with the tested device and a reference pressure-
measuring device (as described in section 6.4.4) or by challenging the
tested device with a reference pressure source (as described in section
6.4.4) or by performing an equivalent check using a reference device
approved by the Administrator.
10.8.2 Acceptance criterion. At the selected pressure setting, the
pressure readings made using the reference device and the tested device
shall agree to within 3 percent of full scale of the tested device or
0.8 mm H2O (0.03 in. H2O), whichever is less
restrictive. If this
[[Page 62]]
specification is met, the test data collected during the field test are
valid. If the specification is not met, all test data collected since
the last successful calibration or calibration check are invalid and
shall be repeated using a pressure-measuring device with a current,
valid calibration. Any device that fails the calibration check shall not
be used in a field test until a successful recalibration is performed
according to the procedures in section 10.3.3.
10.9 Temperature Gauges. Same as Method 2, section 4.3. The
alternative thermocouple calibration procedures outlined in Emission
Measurement Center (EMC) Approved Alternative Method (ALT-011)
``Alternative Method 2 Thermocouple Calibration Procedure'' may be
performed. Temperature gauges shall be calibrated no more than 30 days
prior to the start of a field test or series of field tests and
recalibrated no more than 30 days after completion of a field test or
series of field tests.
10.10 Barometer. Same as Method 2, section 4.4. The barometer shall
be calibrated no more than 30 days prior to the start of a field test or
series of field tests.
11.0 Analytical Procedure
Sample collection and analysis are concurrent for this method (see
section 8.0).
12.0 Data Analysis and Calculations
These calculations use the measured yaw angle, derived pitch angle,
and the differential pressure and temperature measurements at individual
traverse points to derive the axial flue gas velocity (va(i))
at each of those points. The axial velocity values at all traverse
points that comprise a full stack or duct traverse are then averaged to
obtain the average axial flue gas velocity (va (avg)). Round
off figures only in the final calculation of reported values.
12.1 Nomenclature
A = Cross-sectional area of stack or duct, m\2\ (ft \2\).
Bws = Water vapor in the gas stream (from Method 4 or
alternative), proportion by volume.
Kp Conversion factor (a constant),
[GRAPHIC] [TIFF OMITTED] TR14MY99.052
for the metric system, and
[GRAPHIC] [TIFF OMITTED] TR14MY99.053
for the English system.
Md = Molecular weight of stack or duct gas, dry basis (see
section 8.13), g/g-mole (lb/lb-mole).
Ms = Molecular weight of stack or duct gas, wet basis, g/g-
mole (lb/lb-mole).
[GRAPHIC] [TIFF OMITTED] TR14MY99.054
Pbar = Barometric pressure at measurement site, mm Hg (in.
Hg).
Pg = Stack or duct static pressure, mm H2O (in.
H2O).
Ps = Absolute stack or duct pressure, mm Hg (in. Hg),
[GRAPHIC] [TIFF OMITTED] TR14MY99.055
Pstd = Standard absolute pressure, 760 mm Hg (29.92 in. Hg).
13.6 = Conversion from mm H2O (in. H2O) to mm Hg
(in. Hg).
Qsd = Average dry-basis volumetric stack or duct gas flow
rate corrected to standard conditions, dscm/hr (dscf/hr).
Qsw = Average wet-basis volumetric stack or duct gas flow
rate corrected to standard conditions, wscm/hr (wscf/hr).
Ts(avg) = Average absolute stack or duct gas temperature
across all traverse points.
ts(i) = Stack or duct gas temperature, C (F), at traverse
point i.
Ts(i) = Absolute stack or duct gas temperature, K (R), at
traverse point i,
[GRAPHIC] [TIFF OMITTED] TR14MY99.056
for the metric system, and
[GRAPHIC] [TIFF OMITTED] TR14MY99.057
for the English system.
Tstd = Standard absolute temperature, 293 [deg]K (528
[deg]R).
F1(i) = Pitch angle ratio, applicable at traverse point i,
dimensionless.
F2(i) = 3-D probe velocity calibration coefficient,
applicable at traverse point i, dimensionless.
(P4-P5)i = Pitch differential pressure
of stack or duct gas flow, mm H2O (in.
H2O), at traverse point i.
(P1-P2)i = Velocity head (differential
pressure) of stack or duct gas flow, mm H2O (in.
H2O), at traverse point i.
va(i) = Reported stack or duct gas axial velocity, m/sec (ft/
sec), at traverse point i.
va(avg) = Average stack or duct gas axial velocity, m/sec
(ft/sec), across all traverse points.
3,600 = Conversion factor, sec/hr.
18.0 = Molecular weight of water, g/g-mole (lb/lb-mole).
[theta]y(i) = Yaw angle, degrees, at traverse point i.
[theta]p(i) = Pitch angle, degrees, at traverse point i.
n = Number of traverse points.
[[Page 63]]
12.2 Traverse Point Velocity Calculations. Perform the following
calculations from the measurements obtained at each traverse point.
12.2.1 Selection of calibration curves. Select calibration curves as
described in section 10.6.1.
12.2.2 Traverse point pitch angle ratio. Use Equation 2F-1, as
described in section 10.6.2, to calculate the pitch angle ratio,
F1(i), at each traverse point.
12.2.3 Pitch angle. Use the pitch angle ratio, F1(i), to
derive the pitch angle, [theta]p(i), at traverse point i from
the F1 versus pitch angle calibration curve generated under
section 10.6.16.1.
12.2.4 Velocity calibration coefficient. Use the pitch angle,
[theta]p(i), to obtain the probe velocity calibration
coefficient, F2(i), at traverse point i from the ``velocity
pressure calibration curve,'' i.e., the F2 versus pitch angle
calibration curve generated under section 10.6.16.1.
12.2.5 Axial velocity. Use the following equation to calculate the
axial velocity, va(i), from the differential pressure
(P1-P2)i and yaw angle,
[theta]y(i), measured at traverse point i and the previously
calculated values for the velocity calibration coefficient,
F2(i), absolute stack or duct standard temperature,
Ts(i), absolute stack or duct pressure, Ps,
molecular weight, Ms, and pitch angle,
``[theta]p(i).
[GRAPHIC] [TIFF OMITTED] TR14MY99.058
12.2.6 Handling multiple measurements at a traverse point. For
pressure or temperature devices that take multiple measurements at a
traverse point, the multiple measurements (or where applicable, their
square roots) may first be averaged and the resulting average values
used in the equations above. Alternatively, the individual measurements
may be used in the equations above and the resulting multiple calculated
values may then be averaged to obtain a single traverse point value.
With either approach, all of the individual measurements recorded at a
traverse point must be used in calculating the applicable traverse point
value.
12.3 Average Axial Velocity in Stack or Duct. Use the reported
traverse point axial velocity in the following equation.
[GRAPHIC] [TIFF OMITTED] TR14MY99.059
12.4 Acceptability of Results. The test results are acceptable and
the calculated value of va(avg) may be reported as the
average axial velocity for the test run if the conditions in either
section 12.4.1 or 12.4.2 are met.
12.4.1 The calibration curves were generated at nominal velocities
of 18.3 m/sec and 27.4 m/sec (60 ft/sec and 90 ft/sec).
12.4.2 The calibration curves were generated at nominal velocities
other than 18.3 m/sec and 27.4 m/sec (60 ft/sec and 90 ft/sec), and the
value of va(avg) obtained using Equation 2F-9 is less than or
equal to at least one of the nominal velocities used to derive the
F1 and F2 calibration curves.
12.4.3 If the conditions in neither section 12.4.1 nor section
12.4.2 are met, the test results obtained in Equation 2F-9 are not
acceptable, and the steps in sections 12.2 and 12.3 must be repeated
using a set of F1 and F2 calibration curves that
satisfies the conditions specified in section 12.4.1 or 12.4.2.
12.5 Average Gas Wet Volumetric Flow Rate in Stack or Duct. Use the
following equation to compute the average volumetric flow rate on a wet
basis.
[GRAPHIC] [TIFF OMITTED] TR14MY99.060
12.6 Average Gas Dry Volumetric Flow Rate in Stack or Duct. Use the
following equation to compute the average volumetric flow rate on a dry
basis.
[[Page 64]]
[GRAPHIC] [TIFF OMITTED] TR14MY99.061
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Reporting
16.1 Field Test Reports. Field test reports shall be submitted to
the Agency according to applicable regulatory requirements. Field test
reports should, at a minimum, include the following elements.
16.1.1 Description of the source. This should include the name and
location of the test site, descriptions of the process tested, a
description of the combustion source, an accurate diagram of stack or
duct cross-sectional area at the test site showing the dimensions of the
stack or duct, the location of the test ports, and traverse point
locations and identification numbers or codes. It should also include a
description and diagram of the stack or duct layout, showing the
distance of the test location from the nearest upstream and downstream
disturbances and all structural elements (including breachings, baffles,
fans, straighteners, etc.) affecting the flow pattern. If the source and
test location descriptions have been previously submitted to the Agency
in a document (e.g., a monitoring plan or test plan), referencing the
document in lieu of including this information in the field test report
is acceptable.
16.1.2 Field test procedures. These should include a description of
test equipment and test procedures. Testing conventions, such as
traverse point numbering and measurement sequence (e.g., sampling from
center to wall, or wall to center), should be clearly stated. Test port
identification and directional reference for each test port should be
included on the appropriate field test data sheets.
16.1.3 Field test data.
16.1.3.1 Summary of results. This summary should include the dates
and times of testing and the average axial gas velocity and the average
flue gas volumetric flow results for each run and tested condition.
16.1.3.2 Test data. The following values for each traverse point
should be recorded and reported:
(a) P1-P2 and P4-P5
differential pressures
(b) Stack or duct gas temperature at traverse point i
(ts(i))
(c) Absolute stack or duct gas temperature at traverse point i
(Ts(i))
(d) Yaw angle at each traverse point i ([theta]y(i))
(e) Pitch angle at each traverse point i ([theta]p(i))
(f) Stack or duct gas axial velocity at traverse point i
(va(i))
16.1.3.3 The following values should be reported once per run:
(a) Water vapor in the gas stream (from Method 4 or alternative),
proportion by volume (Bws), measured at the frequency
specified in the applicable regulation
(b) Molecular weight of stack or duct gas, dry basis (Md)
(c) Molecular weight of stack or duct gas, wet basis (Ms)
(d) Stack or duct static pressure (Pg)
(e) Absolute stack or duct pressure (Ps)
(f) Carbon dioxide concentration in the flue gas, dry basis (\0/
0\d CO2)
(g) Oxygen concentration in the flue gas, dry basis (\0/
0\d O2)
(h) Average axial stack or duct gas velocity (va(avg))
across all traverse points
(i) Gas volumetric flow rate corrected to standard conditions, dry
or wet basis as required by the applicable regulation (Qsd or
Qsw)
16.1.3.4 The following should be reported once per complete set of test
runs:
(a) Cross-sectional area of stack or duct at the test location (A)
(b) Measurement system response time (sec)
(c) Barometric pressure at measurement site (Pbar)
16.1.4 Calibration data. The field test report should include
calibration data for all probes and test equipment used in the field
test. At a minimum, the probe calibration data reported to the Agency
should include the following:
(a) Date of calibration
(b) Probe type
(c) Probe identification number(s) or code(s)
(d) Probe inspection sheets
(e) Pressure measurements and intermediate calculations of
F1 and F2 at each pitch angle used to obtain
calibration curves in accordance with section 10.6 of this method
(f) Calibration curves (in graphic or equation format) obtained in
accordance with sections 10.6.11 of this method
(g) Description and diagram of wind tunnel used for the calibration,
including dimensions of cross-sectional area and position and size of
the test section
(h) Documentation of wind tunnel qualification tests performed in
accordance with section 10.1 of this method
[[Page 65]]
16.1.5 Quality Assurance. Specific quality assurance and quality
control procedures used during the test should be described.
17.0 Bibliography
(1) 40 CFR Part 60, Appendix A, Method 1--Sample and velocity
traverses for stationary sources.
(2) 40 CFR Part 60, Appendix A, Method 2H--Determination of stack
gas velocity taking into account velocity decay near the stack wall.
(3) 40 CFR Part 60, Appendix A, Method 2--Determination of stack gas
velocity and volumetric flow rate (Type S pitot tube).
(4) 40 CFR Part 60, Appendix A, Method 3--Gas analysis for carbon
dioxide, oxygen, excess air, and dry molecular weight.
(5) 40 CFR Part 60, Appendix A, Method 3A--Determination of oxygen
and carbon dioxide concentrations in emissions from stationary sources
(instrumental analyzer procedure).
(6) 40 CFR Part 60, Appendix A, Method 4--Determination of moisture
content in stack gases.
(7) Emission Measurement Center (EMC) Approved Alternative Method
(ALT-011) ``Alternative Method 2 Thermocouple Calibration Procedure.''
(8) Electric Power Research Institute, Interim Report EPRI TR-
106698, ``Flue Gas Flow Rate Measurement Errors,'' June 1996.
(9) Electric Power Research Institute, Final Report EPRI TR-108110,
``Evaluation of Heat Rate Discrepancy from Continuous Emission
Monitoring Systems,'' August 1997.
(10) Fossil Energy Research Corporation, Final Report, ``Velocity
Probe Tests in Non-axial Flow Fields,'' November 1998, Prepared for the
U.S. Environmental Protection Agency.
(11) Fossil Energy Research Corporation, ``Additional Swirl Tunnel
Tests: E-DAT and T-DAT Probes,'' February 24, 1999, Technical Memorandum
Prepared for U.S. Environmental Protection Agency, P.O. No. 7W-1193-
NALX.
(12) Massachusetts Institute of Technology, Report WBWT-TR-1317,
``Calibration of Eight Wind Speed Probes Over a Reynolds Number Range of
46,000 to 725,000 Per Foot, Text and Summary Plots,'' Plus appendices,
October 15, 1998, Prepared for The Cadmus Group, Inc.
(13) National Institute of Standards and Technology, Special
Publication 250, ``NIST Calibration Services Users Guide 1991,'' Revised
October 1991, U.S. Department of Commerce, p. 2.
(14) National Institute of Standards and Technology, 1998, ``Report
of Special Test of Air Speed Instrumentation, Four Prandtl Probes, Four
S-Type Probes, Four French Probes, Four Modified Kiel Probes,'' Prepared
for the U.S. Environmental Protection Agency under IAG DW13938432-01-0.
(15) National Institute of Standards and Technology, 1998, ``Report
of Special Test of Air Speed Instrumentation, Five Autoprobes,''
Prepared for the U.S. Environmental Protection Agency under IAG
DW13938432-01-0.
(16) National Institute of Standards and Technology, 1998, ``Report
of Special Test of Air Speed Instrumentation, Eight Spherical Probes,''
Prepared for the U.S. Environmental Protection Agency under IAG
DW13938432-01-0.
(17) National Institute of Standards and Technology, 1998, ``Report
of Special Test of Air Speed Instrumentation, Four DAT Probes,''
Prepared for the U.S. Environmental Protection Agency under IAG
DW13938432-01-0.
(18) Norfleet, S.K., ``An Evaluation of Wall Effects on Stack Flow
Velocities and Related Overestimation Bias in EPA's Stack Flow Reference
Methods,'' EPRI CEMS User's Group Meeting, New Orleans, Louisiana, May
13-15, 1998.
(19) Page, J.J., E.A. Potts, and R.T. Shigehara, ``3-D Pitot Tube
Calibration Study,'' EPA Contract No. 68-D1-0009, Work Assignment No. I-
121, March 11, 1993.
(20) Shigehara, R.T., W.F. Todd, and W.S. Smith, ``Significance of
Errors in Stack Sampling Measurements,'' Presented at the Annual Meeting
of the Air Pollution Control Association, St. Louis, Missouri, June 14-
19, 1970.
(21) The Cadmus Group, Inc., May 1999, ``EPA Flow Reference Method
Testing and Analysis: Findings Report,'' EPA/430-R-99-009.
(22) The Cadmus Group, Inc., 1998, ``EPA Flow Reference Method
Testing and Analysis: Data Report, Texas Utilities, DeCordova Steam
Electric Station, Volume I: Test Description and Appendix A (Data
Distribution Package),'' EPA/430-R-98-015a.
(23) The Cadmus Group, Inc., 1998, ``EPA Flow Reference Method
Testing and Analysis: Data Report, Texas Utilities, Lake Hubbard Steam
Electric Station, Volume I: Test Description and Appendix A (Data
Distribution Package),'' EPA/430-R-98-017a.
(24) The Cadmus Group, Inc., 1998, ``EPA Flow Reference Method
Testing and Analysis: Data Report, Pennsylvania Electric Co., G.P.U.
Genco Homer City Station: Unit 1, Volume I: Test Description and
Appendix A (Data Distribution Package),'' EPA/430-R-98-018a.
(25) The Cadmus Group, Inc., 1997, ``EPA Flow Reference Method
Testing and Analysis: Wind Tunnel Experimental Results,'' EPA/430-R-97-
013.
18.0 Annexes
Annex A, C, and D describe recommended procedures for meeting
certain provisions in sections 8.3, 10.4, and 10.5 of this method. Annex
B describes procedures to be followed
[[Page 66]]
when using the protractor wheel and pointer assembly to measure yaw
angles, as provided under section 8.9.1.
18.1 Annex A--Rotational Position Check. The following are
recommended procedures that may be used to satisfy the rotational
position check requirements of section 8.3 of this method and to
determine the angle-measuring device rotational offset RADO.
18.1.1 Rotational position check with probe outside stack. Where
physical constraints at the sampling location allow full assembly of the
probe outside the stack and insertion into the test port, the following
procedures should be performed before the start of testing. Two angle-
measuring devices that meet the specifications in section 6.2.1 or 6.2.3
are required for the rotational position check. An angle measuring
device whose position can be independently adjusted (e.g., by means of a
set screw) after being locked into position on the probe sheath shall
not be used for this check unless the independent adjustment is set so
that the device performs exactly like a device without the capability
for independent adjustment. That is, when aligned on the probe such a
device must give the same reading as a device that does not have the
capability of being independently adjusted. With the fully assembled
probe (including probe shaft extensions, if any) secured in a horizontal
position, affix one yaw angle-measuring device to the probe sheath and
lock it into position on the reference scribe line specified in section
6.1.6.1. Position the second angle-measuring device using the procedure
in section 18.1.1.1 or 18.1.1.2.
18.1.1.1 Marking procedure. The procedures in this section should be
performed at each location on the fully assembled probe where the yaw
angle-measuring device will be mounted during the velocity traverse.
Place the second yaw angle-measuring device on the main probe sheath (or
extension) at the position where a yaw angle will be measured during the
velocity traverse. Adjust the position of the second angle-measuring
device until it indicates the same angle (1[deg])
as the reference device, and affix the second device to the probe sheath
(or extension). Record the angles indicated by the two angle-measuring
devices on a form similar to Table 2F-2. In this position, the second
angle-measuring device is considered to be properly positioned for yaw
angle measurement. Make a mark, no wider than 1.6 mm (1/16 in.), on the
probe sheath (or extension), such that the yaw angle-measuring device
can be re-affixed at this same properly aligned position during the
velocity traverse.
18.1.1.2 Procedure for probe extensions with scribe lines. If,
during a velocity traverse the angle-measuring device will be affixed to
a probe extension having a scribe line as specified in section 6.1.6.2,
the following procedure may be used to align the extension's scribe line
with the reference scribe line instead of marking the extension as
described in section 18.1.1.1. Attach the probe extension to the main
probe. Align and lock the second angle-measuring device on the probe
extension's scribe line. Then, rotate the extension until both measuring
devices indicate the same angle (1[deg]). Lock the
extension at this rotational position. Record the angles indicated by
the two angle-measuring devices on a form similar to Table 2F-2. An
angle-measuring device may be aligned at any position on this scribe
line during the velocity traverse, if the scribe line meets the
alignment specification in section 6.1.6.3.
18.1.1.3 Post-test rotational position check. If the fully assembled
probe includes one or more extensions, the following check should be
performed immediately after the completion of a velocity traverse. At
the discretion of the tester, additional checks may be conducted after
completion of testing at any sample port. Without altering the alignment
of any of the components of the probe assembly used in the velocity
traverse, secure the fully assembled probe in a horizontal position.
Affix an angle-measuring device at the reference scribe line specified
in section 6.1.6.1. Use the other angle-measuring device to check the
angle at each location where the device was checked prior to testing.
Record the readings from the two angle-measuring devices.
18.1.2 Rotational position check with probe in stack. This section
applies only to probes that, due to physical constraints, cannot be
inserted into the test port as fully assembled with all necessary
extensions needed to reach the inner-most traverse point(s).
18.1.2.1 Perform the out-of-stack procedure in section 18.1.1 on the
main probe and any attached extensions that will be initially inserted
into the test port.
18.1.2.2 Use the following procedures to perform additional
rotational position check(s) with the probe in the stack, each time a
probe extension is added. Two angle-measuring devices are required. The
first of these is the device that was used to measure yaw angles at the
preceding traverse point, left in its properly aligned measurement
position. The second angle-measuring device is positioned on the added
probe extension. Use the applicable procedures in section 18.1.1.1 or
18.1.1.2 to align, adjust, lock, and mark (if necessary) the position of
the second angle-measuring device to within 1[deg]
of the first device. Record the readings of the two devices on a form
similar to Table 2F-2.
18.1.2.3 The procedure in section 18.1.2.2 should be performed at
the first port where measurements are taken. The procedure should be
repeated each time a probe extension is re-attached at a subsequent
port, unless the probe extensions are designed to be locked into a
mechanically fixed rotational position (e.g., through use of
interlocking
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grooves), which can be reproduced from port to port as specified in
section 8.3.5.2.
18.2 Annex B--Angle Measurement Protocol for Protractor Wheel and
Pointer Device. The following procedure shall be used when a protractor
wheel and pointer assembly, such as the one described in section 6.2.2
and illustrated in Figure 2F-7 is used to measure the yaw angle of flow.
With each move to a new traverse point, unlock, re-align, and re-lock
the probe, angle-pointer collar, and protractor wheel to each other. At
each such move, particular attention is required to ensure that the
scribe line on the angle pointer collar is either aligned with the
reference scribe line on the main probe sheath or is at the rotational
offset position established under section 8.3.1. The procedure consists
of the following steps:
18.2.1 Affix a protractor wheel to the entry port for the test probe
in the stack or duct.
18.2.2 Orient the protractor wheel so that the 0[deg] mark
corresponds to the longitudinal axis of the stack or duct. For stacks,
vertical ducts, or ports on the side of horizontal ducts, use a digital
inclinometer meeting the specifications in section 6.2.1 to locate the
0[deg] orientation. For ports on the top or bottom of horizontal ducts,
identify the longitudinal axis at each test port and permanently mark
the duct to indicate the 0[deg] orientation. Once the protractor wheel
is properly aligned, lock it into position on the test port.
18.2.3 Move the pointer assembly along the probe sheath to the
position needed to take measurements at the first traverse point. Align
the scribe line on the pointer collar with the reference scribe line or
at the rotational offset position established under section 8.3.1.
Maintaining this rotational alignment, lock the pointer device onto the
probe sheath. Insert the probe into the entry port to the depth needed
to take measurements at the first traverse point.
18.2.4 Perform the yaw angle determination as specified in sections
8.9.3 and 8.9.4 and record the angle as shown by the pointer on the
protractor wheel. Then, take velocity pressure and temperature
measurements in accordance with the procedure in section 8.9.5. Perform
the alignment check described in section 8.9.6.
18.2.5 After taking velocity pressure measurements at that traverse
point, unlock the probe from the collar and slide the probe through the
collar to the depth needed to reach the next traverse point.
18.2.6 Align the scribe line on the pointer collar with the
reference scribe line on the main probe or at the rotational offset
position established under section 8.3.1. Lock the collar onto the
probe.
18.2.7 Repeat the steps in sections 18.2.4 through 18.2.6 at the
remaining traverse points accessed from the current stack or duct entry
port.
18.2.8 After completing the measurement at the last traverse point
accessed from a port, verify that the orientation of the protractor
wheel on the test port has not changed over the course of the traverse
at that port. For stacks, vertical ducts, or ports on the side of
horizontal ducts, use a digital inclinometer meeting the specifications
in section 6.2.1 to check the rotational position of the 0[deg] mark on
the protractor wheel. For ports on the top or bottom of horizontal
ducts, observe the alignment of the angle wheel 0[deg] mark relative to
the permanent 0[deg] mark on the duct at that test port. If these
observed comparisons exceed 2[deg] of 0[deg], all
angle and pressure measurements taken at that port since the protractor
wheel was last locked into position on the port shall be repeated.
18.2.9 Move to the next stack or duct entry port and repeat the
steps in sections 18.2.1 through 18.2.8.
18.3 Annex C--Guideline for Reference Scribe Line Placement. Use of
the following guideline is recommended to satisfy the requirements of
section 10.4 of this method. The rotational position of the reference
scribe line should be either 90[deg] or 180[deg] from the probe's impact
pressure port.
18.4 Annex D--Determination of Reference Scribe Line Rotational
Offset. The following procedures are recommended for determining the
magnitude and sign of a probe's reference scribe line rotational offset,
RSLO. Separate procedures are provided for two types of
angle-measuring devices: digital inclinometers and protractor wheel and
pointer assemblies.
18.4.1 Perform the following procedures on the main probe with all
devices that will be attached to the main probe in the field [such as
thermocouples or resistance temperature detectors (RTDs)] that may
affect the flow around the probe head. Probe shaft extensions that do
not affect flow around the probe head need not be attached during
calibration.
18.4.2 The procedures below assume that the wind tunnel duct used
for probe calibration is horizontal and that the flow in the calibration
wind tunnel is axial as determined by the axial flow verification check
described in section 10.1.2. Angle-measuring devices are assumed to
display angles in alternating 0[deg] to 90[deg] and 90[deg] to 0[deg]
intervals. If angle-measuring devices with other readout conventions are
used or if other calibration wind tunnel duct configurations are used,
make the appropriate calculational corrections.
18.4.2.1 Position the angle-measuring device in accordance with one
of the following procedures.
18.4.2.1.1 If using a digital inclinometer, affix the calibrated
digital inclinometer to the probe. If the digital inclinometer can be
independently adjusted after being locked
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into position on the probe sheath (e.g., by means of a set screw), the
independent adjustment must be set so that the device performs exactly
like a device without the capability for independent adjustment. That
is, when aligned on the probe the device must give the same readings as
a device that does not have the capability of being independently
adjusted. Either align it directly on the reference scribe line or on a
mark aligned with the scribe line determined according to the procedures
in section 18.1.1.1. Maintaining this rotational alignment, lock the
digital inclinometer onto the probe sheath.
18.4.2.1.2 If using a protractor wheel and pointer device, orient
the protractor wheel on the test port so that the 0[deg] mark is aligned
with the longitudinal axis of the wind tunnel duct. Maintaining this
alignment, lock the wheel into place on the wind tunnel test port. Align
the scribe line on the pointer collar with the reference scribe line or
with a mark aligned with the reference scribe line, as determined under
section 18.1.1.1. Maintaining this rotational alignment, lock the
pointer device onto the probe sheath.
18.4.2.2 Zero the pressure-measuring device used for yaw nulling.
18.4.2.3 Insert the probe assembly into the wind tunnel through the
entry port, positioning the probe's impact port at the calibration
location. Check the responsiveness of the pressure-measuring device to
probe rotation, taking corrective action if the response is
unacceptable.
18.4.2.4 Ensure that the probe is in a horizontal position using a
carpenter's level.
18.4.2.5 Rotate the probe either clockwise or counterclockwise until
a yaw null (P2 = P3) is obtained.
18.4.2.6 Read and record the value of [theta]null, the
angle indicated by the angle-measuring device at the yaw-null position.
Record the angle reading on a form similar to Table 2F-6. Do not
associate an algebraic sign with this reading.
18.4.2.7 Determine the magnitude and algebraic sign of the reference
scribe line rotational offset, RSLO. The magnitude of
RSLO will be equal to either [theta]null or
(90[deg]-[theta]null), depending on the angle-measuring
device used. (See Table 2F-7 for a summary.) The algebraic sign of
RSLO will either be positive, if the rotational position of
the reference scribe line is clockwise, or negative, if counterclockwise
with respect to the probe's yaw-null position. Figure 2F-13 illustrates
how the magnitude and sign of RSLO are determined.
18.4.2.8 Perform the steps in sections 18.4.2.3 through 18.4.2.7
twice at each of the two calibration velocities selected for the probe
under section 10.6. Record the values of RSLO in a form
similar to Table 2F-6.
18.4.2.9 The average of all RSLO values is the reference
scribe line rotational offset for the probe.
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[36 FR 24877, Dec. 23, 1971]
Editorial Note: For Federal Register citations affecting appendix A-
1 to part 60, see the List of CFR sections Affected, which appears in
the Finding Aids section of the printed volume and at www.govinfo.gov.
[[Page 88]]
Editorial Note: At 79 FR 11257, Feb. 27, 2014, Figure 1-2 was added
to part 60, appendix A-1, method 1, section 17. However, this amendment
could not be performed because Figure 1-2 already existed.
Sec. Appendix A-2 to Part 60--Test Methods 2G through 3C
Method 2G--Determination of Stack Gas Velocity and Volumetric Flow Rate
With Two-Dimensional Probes
Method 2H--Determination of Stack Gas Velocity Taking Into Account
Velocity Decay Near the Stack Wall
Method 3--Gas analysis for the determination of dry molecular weight
Method 3A--Determination of Oxygen and Carbon Dioxide Concentrations in
Emissions From Stationary Sources (Instrumental Analyzer
Procedure)
Method 3B--Gas analysis for the determination of emission rate
correction factor or excess air
Method 3C--Determination of carbon dioxide, methane, nitrogen, and
oxygen from stationary sources
The test methods in this appendix are referred to in Sec. 60.8
(Performance Tests) and Sec. 60.11 (Compliance With Standards and
Maintenance Requirements) of 40 CFR part 60, subpart A (General
Provisions). Specific uses of these test methods are described in the
standards of performance contained in the subparts, beginning with
Subpart D.
Within each standard of performance, a section title ``Test Methods
and Procedures'' is provided to: (1) Identify the test methods to be
used as reference methods to the facility subject to the respective
standard and (2) identify any special instructions or conditions to be
followed when applying a method to the respective facility. Such
instructions (for example, establish sampling rates, volumes, or
temperatures) are to be used either in addition to, or as a substitute
for procedures in a test method. Similarly, for sources subject to
emission monitoring requirements, specific instructions pertaining to
any use of a test method as a reference method are provided in the
subpart or in Appendix B.
Inclusion of methods in this appendix is not intended as an
endorsement or denial of their applicability to sources that are not
subject to standards of performance. The methods are potentially
applicable to other sources; however, applicability should be confirmed
by careful and appropriate evaluation of the conditions prevalent at
such sources.
The approach followed in the formulation of the test methods
involves specifications for equipment, procedures, and performance. In
concept, a performance specification approach would be preferable in all
methods because this allows the greatest flexibility to the user. In
practice, however, this approach is impractical in most cases because
performance specifications cannot be established. Most of the methods
described herein, therefore, involve specific equipment specifications
and procedures, and only a few methods in this appendix rely on
performance criteria.
Minor changes in the test methods should not necessarily affect the
validity of the results and it is recognized that alternative and
equivalent methods exist. section 60.8 provides authority for the
Administrator to specify or approve (1) equivalent methods, (2)
alternative methods, and (3) minor changes in the methodology of the
test methods. It should be clearly understood that unless otherwise
identified all such methods and changes must have prior approval of the
Administrator. An owner employing such methods or deviations from the
test methods without obtaining prior approval does so at the risk of
subsequent disapproval and retesting with approved methods.
Within the test methods, certain specific equipment or procedures
are recognized as being acceptable or potentially acceptable and are
specifically identified in the methods. The items identified as
acceptable options may be used without approval but must be identified
in the test report. The potentially approvable options are cited as
``subject to the approval of the Administrator'' or as ``or
equivalent.'' Such potentially approvable techniques or alternatives may
be used at the discretion of the owner without prior approval. However,
detailed descriptions for applying these potentially approvable
techniques or alternatives are not provided in the test methods. Also,
the potentially approvable options are not necessarily acceptable in all
applications. Therefore, an owner electing to use such potentially
approvable techniques or alternatives is responsible for: (1) assuring
that the techniques or alternatives are in fact applicable and are
properly executed; (2) including a written description of the
alternative method in the test report (the written method must be clear
and must be capable of being performed without additional instruction,
and the degree of detail should be similar to the detail contained in
the test methods); and (3) providing any rationale or supporting data
necessary to show the validity of the alternative in the particular
application. Failure to meet these requirements can result in the
Administrator's disapproval of the alternative.
[[Page 89]]
Method 2G--Determination of Stack Gas Velocity and Volumetric Flow Rate
With Two-Dimensional Probes
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling) essential to its
performance. Some material has been incorporated from other methods in
this part. Therefore, to obtain reliable results, those using this
method should have a thorough knowledge of at least the following
additional test methods: Methods 1, 2, 3 or 3A, and 4.
1.0 Scope and Application
1.1 This method is applicable for the determination of yaw angle,
near-axial velocity, and the volumetric flow rate of a gas stream in a
stack or duct using a two-dimensional (2-D) probe.
2.0 Summary of Method
2.1 A 2-D probe is used to measure the velocity pressure and the yaw
angle of the flow velocity vector in a stack or duct. Alternatively,
these measurements may be made by operating one of the three-dimensional
(3-D) probes described in Method 2F, in yaw determination mode only.
From these measurements and a determination of the stack gas density,
the average near-axial velocity of the stack gas is calculated. The
near-axial velocity accounts for the yaw, but not the pitch, component
of flow. The average gas volumetric flow rate in the stack or duct is
then determined from the average near-axial velocity.
3.0 Definitions
3.1. Angle-measuring Device Rotational Offset (RADO). The rotational
position of an angle-measuring device relative to the reference scribe
line, as determined during the pre-test rotational position check
described in section 8.3.
3.2 Calibration Pitot Tube. The standard (Prandtl type) pitot tube
used as a reference when calibrating a probe under this method.
3.3 Field Test. A set of measurements conducted at a specific unit
or exhaust stack/duct to satisfy the applicable regulation (e.g., a
three-run boiler performance test, a single-or multiple-load nine-run
relative accuracy test).
3.4 Full Scale of Pressure-measuring Device. Full scale refers to
the upper limit of the measurement range displayed by the device. For
bi-directional pressure gauges, full scale includes the entire pressure
range from the lowest negative value to the highest positive value on
the pressure scale.
3.5 Main probe. Refers to the probe head and that section of probe
sheath directly attached to the probe head. The main probe sheath is
distinguished from probe extensions, which are sections of sheath added
onto the main probe to extend its reach.
3.6 ``May,'' ``Must,'' ``Shall,'' ``Should,'' and the imperative
form of verbs.
3.6.1 ``May'' is used to indicate that a provision of this method is
optional.
3.6.2 ``Must,'' ``Shall,'' and the imperative form of verbs (such as
``record'' or ``enter'') are used to indicate that a provision of this
method is mandatory.
3.6.3 ``Should'' is used to indicate that a provision of this method
is not mandatory, but is highly recommended as good practice.
3.7 Method 1. Refers to 40 CFR part 60, appendix A, ``Method 1--
Sample and velocity traverses for stationary sources.''
3.8 Method 2. Refers to 40 CFR part 60, appendix A, ``Method 2--
Determination of stack gas velocity and volumetric flow rate (Type S
pitot tube).''
3.9 Method 2F. Refers to 40 CFR part 60, appendix A, ``Method 2F--
Determination of stack gas velocity and volumetric flow rate with three-
dimensional probes.''
3.10 Near-axial Velocity. The velocity vector parallel to the axis
of the stack or duct that accounts for the yaw angle component of gas
flow. The term ``near-axial'' is used herein to indicate that the
velocity and volumetric flow rate results account for the measured yaw
angle component of flow at each measurement point.
3.11 Nominal Velocity. Refers to a wind tunnel velocity setting that
approximates the actual wind tunnel velocity to within 1.5 m/sec (5 ft/sec).
3.12 Pitch Angle. The angle between the axis of the stack or duct
and the pitch component of flow, i.e., the component of the total
velocity vector in a plane defined by the traverse line and the axis of
the stack or duct. (Figure 2G-1 illustrates the ``pitch plane.'') From
the standpoint of a tester facing a test port in a vertical stack, the
pitch component of flow is the vector of flow moving from the center of
the stack toward or away from that test port. The pitch angle is the
angle described by this pitch component of flow and the vertical axis of
the stack.
3.13 Readability. For the purposes of this method, readability for
an analog measurement device is one half of the smallest scale division.
For a digital measurement device, it is the number of decimals displayed
by the device.
3.14 Reference Scribe Line. A line permanently inscribed on the main
probe sheath (in accordance with section 6.1.5.1) to serve as a
reference mark for determining yaw angles.
3.15 Reference Scribe Line Rotational Offset (RSLO). The rotational
position of a probe's reference scribe line relative to the probe's yaw-
null position, as determined during the yaw angle calibration described
in section 10.5.
[[Page 90]]
3.16 Response Time. The time required for the measurement system to
fully respond to a change from zero differential pressure and ambient
temperature to the stable stack or duct pressure and temperature
readings at a traverse point.
3.17 Tested Probe. A probe that is being calibrated.
3.18 Three-dimensional (3-D) Probe. A directional probe used to
determine the velocity pressure and the yaw and pitch angles in a
flowing gas stream.
3.19 Two-dimensional (2-D) Probe. A directional probe used to
measure velocity pressure and yaw angle in a flowing gas stream.
3.20 Traverse Line. A diameter or axis extending across a stack or
duct on which measurements of velocity pressure and flow angles are
made.
3.21 Wind Tunnel Calibration Location. A point, line, area, or
volume within the wind tunnel test section at, along, or within which
probes are calibrated. At a particular wind tunnel velocity setting, the
average velocity pressures at specified points at, along, or within the
calibration location shall vary by no more than 2 percent or 0.3 mm
H20 (0.01 in. H2O), whichever is less restrictive,
from the average velocity pressure at the calibration pitot tube
location. Air flow at this location shall be axial, i.e., yaw and pitch
angles within 3[deg] of 0[deg]. Compliance with
these flow criteria shall be demonstrated by performing the procedures
prescribed in sections 10.1.1 and 10.1.2. For circular tunnels, no part
of the calibration location may be closer to the tunnel wall than 10.2
cm (4 in.) or 25 percent of the tunnel diameter, whichever is farther
from the wall. For elliptical or rectangular tunnels, no part of the
calibration location may be closer to the tunnel wall than 10.2 cm (4
in.) or 25 percent of the applicable cross-sectional axis, whichever is
farther from the wall.
3.22 Wind Tunnel with Documented Axial Flow. A wind tunnel facility
documented as meeting the provisions of sections 10.1.1 (velocity
pressure cross-check) and 10.1.2 (axial flow verification) using the
procedures described in these sections or alternative procedures
determined to be technically equivalent.
3.23 Yaw Angle. The angle between the axis of the stack or duct and
the yaw component of flow, i.e., the component of the total velocity
vector in a plane perpendicular to the traverse line at a particular
traverse point. (Figure 2G-1 illustrates the ``yaw plane.'') From the
standpoint of a tester facing a test port in a vertical stack, the yaw
component of flow is the vector of flow moving to the left or right from
the center of the stack as viewed by the tester. (This is sometimes
referred to as ``vortex flow,'' i.e., flow around the centerline of a
stack or duct.) The yaw angle is the angle described by this yaw
component of flow and the vertical axis of the stack. The algebraic sign
convention is illustrated in Figure 2G-2.
3.24 Yaw Nulling. A procedure in which a Type-S pitot tube or a 3-D
probe is rotated about its axis in a stack or duct until a zero
differential pressure reading (``yaw null'') is obtained. When a Type S
probe is yaw-nulled, the rotational position of its impact port is
90[deg] from the direction of flow in the stack or duct and the [Delta]P
reading is zero. When a 3-D probe is yaw-nulled, its impact pressure
port (P1) faces directly into the direction of flow in the
stack or duct and the differential pressure between pressure ports
P2 and P3 is zero.
4.0 Interferences [Reserved]
5.0 Safety
5.1 This test method may involve hazardous operations and the use of
hazardous materials or equipment. This method does not purport to
address all of the safety problems associated with its use. It is the
responsibility of the user to establish and implement appropriate safety
and health practices and to determine the applicability of regulatory
limitations before using this test method.
6.0 Equipment and Supplies
6.1 Two-dimensional Probes. Probes that provide both the velocity
pressure and the yaw angle of the flow vector in a stack or duct, as
listed in sections 6.1.1 and 6.1.2, qualify for use based on
comprehensive wind tunnel and field studies involving both inter-and
intra-probe comparisons by multiple test teams. Each 2-D probe shall
have a unique identification number or code permanently marked on the
main probe sheath. Each probe shall be calibrated prior to use according
to the procedures in section 10. Manufacturer-supplied calibration data
shall be used as example information only, except when the manufacturer
calibrates the probe as specified in section 10 and provides complete
documentation.
6.1.1 Type S (Stausscheibe or reverse type) pitot tube. This is the
same as specified in Method 2, section 2.1, except for the following
additional specifications that enable the pitot tube to accurately
determine the yaw component of flow. For the purposes of this method,
the external diameter of the tubing used to construct the Type S pitot
tube (dimension Dt in Figure 2-2 of Method 2) shall be no
less than 9.5 mm (3/8 in.). The pitot tube shall also meet the following
alignment specifications. The angles [alpha]1,
[alpha]2, [beta]1, and [beta]2, as
shown in Method 2, Figure 2-3, shall not exceed 2[deg]. The dimensions w and z, shown in Method 2,
Figure 2-3 shall not exceed 0.5 mm (0.02 in.).
[[Page 91]]
6.1.1.1 Manual Type S probe. This refers to a Type S probe that is
positioned at individual traverse points and yaw nulled manually by an
operator.
6.1.1.2 Automated Type S probe. This refers to a system that uses a
computer-controlled motorized mechanism to position the Type S pitot
head at individual traverse points and perform yaw angle determinations.
6.1.2 Three-dimensional probes used in 2-D mode. A 3-D probe, as
specified in sections 6.1.1 through 6.1.3 of Method 2F, may, for the
purposes of this method, be used in a two-dimensional mode (i.e.,
measuring yaw angle, but not pitch angle). When the 3-D probe is used as
a 2-D probe, only the velocity pressure and yaw-null pressure are
obtained using the pressure taps referred to as P1,
P2, and P3. The differential pressure
P1-P2 is a function of total velocity and
corresponds to the [Delta]P obtained using the Type S probe. The
differential pressure P2-P3 is used to yaw null
the probe and determine the yaw angle. The differential pressure
P4-P5, which is a function of pitch angle, is not
measured when the 3-D probe is used in 2-D mode.
6.1.3 Other probes. [Reserved]
6.1.4 Probe sheath. The probe shaft shall include an outer sheath
to: (1) provide a surface for inscribing a permanent reference scribe
line, (2) accommodate attachment of an angle-measuring device to the
probe shaft, and (3) facilitate precise rotational movement of the probe
for determining yaw angles. The sheath shall be rigidly attached to the
probe assembly and shall enclose all pressure lines from the probe head
to the farthest position away from the probe head where an angle-
measuring device may be attached during use in the field. The sheath of
the fully assembled probe shall be sufficiently rigid and straight at
all rotational positions such that, when one end of the probe shaft is
held in a horizontal position, the fully extended probe meets the
horizontal straightness specifications indicated in section 8.2 below.
6.1.5 Scribe lines.
6.1.5.1 Reference scribe line. A permanent line, no greater than 1.6
mm (1/16 in.) in width, shall be inscribed on each manual probe that
will be used to determine yaw angles of flow. This line shall be placed
on the main probe sheath in accordance with the procedures described in
section 10.4 and is used as a reference position for installation of the
yaw angle-measuring device on the probe. At the discretion of the
tester, the scribe line may be a single line segment placed at a
particular position on the probe sheath (e.g., near the probe head),
multiple line segments placed at various locations along the length of
the probe sheath (e.g., at every position where a yaw angle-measuring
device may be mounted), or a single continuous line extending along the
full length of the probe sheath.
6.1.5.2 Scribe line on probe extensions. A permanent line may also
be inscribed on any probe extension that will be attached to the main
probe in performing field testing. This allows a yaw angle-measuring
device mounted on the extension to be readily aligned with the reference
scribe line on the main probe sheath.
6.1.5.3 Alignment specifications. This specification shall be met
separately, using the procedures in section 10.4.1, on the main probe
and on each probe extension. The rotational position of the scribe line
or scribe line segments on the main probe or any probe extension must
not vary by more than 2[deg]. That is, the difference between the
minimum and maximum of all of the rotational angles that are measured
along the full length of the main probe or the probe extension must not
exceed 2[deg].
6.1.6 Probe and system characteristics to ensure horizontal
stability.
6.1.6.1 For manual probes, it is recommended that the effective
length of the probe (coupled with a probe extension, if necessary) be at
least 0.9 m (3 ft.) longer than the farthest traverse point mark on the
probe shaft away from the probe head. The operator should maintain the
probe's horizontal stability when it is fully inserted into the stack or
duct. If a shorter probe is used, the probe should be inserted through a
bushing sleeve, similar to the one shown in Figure 2G-3, that is
installed on the test port; such a bushing shall fit snugly around the
probe and be secured to the stack or duct entry port in such a manner as
to maintain the probe's horizontal stability when fully inserted into
the stack or duct.
6.1.6.2 An automated system that includes an external probe casing
with a transport system shall have a mechanism for maintaining
horizontal stability comparable to that obtained by manual probes
following the provisions of this method. The automated probe assembly
shall also be constructed to maintain the alignment and position of the
pressure ports during sampling at each traverse point. The design of the
probe casing and transport system shall allow the probe to be removed
from the stack or duct and checked through direct physical measurement
for angular position and insertion depth.
6.1.7 The tubing that is used to connect the probe and the pressure-
measuring device should have an inside diameter of at least 3.2 mm (\1/
8\ in.), to reduce the time required for pressure equilibration, and
should be as short as practicable.
6.1.8 If a detachable probe head without a sheath [e.g., a pitot
tube, typically 15.2 to 30.5 cm (6 to 12 in.) in length] is coupled with
a probe sheath and calibrated in a wind tunnel in accordance with the
yaw angle calibration procedure in section 10.5, the probe head shall
remain attached to the probe
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sheath during field testing in the same configuration and orientation as
calibrated. Once the detachable probe head is uncoupled or re-oriented,
the yaw angle calibration of the probe is no longer valid and must be
repeated before using the probe in subsequent field tests.
6.2 Yaw Angle-measuring Device. One of the following devices shall
be used for measurement of the yaw angle of flow.
6.2.1 Digital inclinometer. This refers to a digital device capable
of measuring and displaying the rotational position of the probe to
within 1[deg]. The device shall be able to be
locked into position on the probe sheath or probe extension, so that it
indicates the probe's rotational position throughout the test. A
rotational position collar block that can be attached to the probe
sheath (similar to the collar shown in Figure 2G-4) may be required to
lock the digital inclinometer into position on the probe sheath.
6.2.2 Protractor wheel and pointer assembly. This apparatus, similar
to that shown in Figure 2G-5, consists of the following components.
6.2.2.1 A protractor wheel that can be attached to a port opening
and set in a fixed rotational position to indicate the yaw angle
position of the probe's scribe line relative to the longitudinal axis of
the stack or duct. The protractor wheel must have a measurement ring on
its face that is no less than 17.8 cm (7 in.) in diameter, shall be able
to be rotated to any angle and then locked into position on the stack or
duct test port, and shall indicate angles to a resolution of 1[deg].
6.2.2.2 A pointer assembly that includes an indicator needle mounted
on a collar that can slide over the probe sheath and be locked into a
fixed rotational position on the probe sheath. The pointer needle shall
be of sufficient length, rigidity, and sharpness to allow the tester to
determine the probe's angular position to within 1[deg] from the
markings on the protractor wheel. Corresponding to the position of the
pointer, the collar must have a scribe line to be used in aligning the
pointer with the scribe line on the probe sheath.
6.2.3 Other yaw angle-measuring devices. Other angle-measuring
devices with a manufacturer's specified precision of 1[deg] or better
may be used, if approved by the Administrator.
6.3 Probe Supports and Stabilization Devices. When probes are used
for determining flow angles, the probe head should be kept in a stable
horizontal position. For probes longer than 3.0 m (10 ft.), the section
of the probe that extends outside the test port shall be secured. Three
alternative devices are suggested for maintaining the horizontal
position and stability of the probe shaft during flow angle
determinations and velocity pressure measurements: (1) monorails
installed above each port, (2) probe stands on which the probe shaft may
be rested, or (3) bushing sleeves of sufficient length secured to the
test ports to maintain probes in a horizontal position. Comparable
provisions shall be made to ensure that automated systems maintain the
horizontal position of the probe in the stack or duct. The physical
characteristics of each test platform may dictate the most suitable type
of stabilization device. Thus, the choice of a specific stabilization
device is left to the judgement of the testers.
6.4 Differential Pressure Gauges. The velocity pressure ([Delta]P)
measuring devices used during wind tunnel calibrations and field testing
shall be either electronic manometers (e.g., pressure transducers),
fluid manometers, or mechanical pressure gauges (e.g.,
Magnehelic[Delta] gauges). Use of electronic manometers is
recommended. Under low velocity conditions, use of electronic manometers
may be necessary to obtain acceptable measurements.
6.4.1 Differential pressure-measuring device. This refers to a
device capable of measuring pressure differentials and having a
readability of 1 percent of full scale. The device
shall be capable of accurately measuring the maximum expected pressure
differential. Such devices are used to determine the following pressure
measurements: velocity pressure, static pressure, and yaw-null pressure.
For an inclined-vertical manometer, the readability specification of
1 percent shall be met separately using the
respective full-scale upper limits of the inclined anvertical portions
of the scales. To the extent practicable, the device shall be selected
such that most of the pressure readings are between 10 and 90 percent of
the device's full-scale measurement range (as defined in section 3.4).
In addition, pressure-measuring devices should be selected such that the
zero does not drift by more than 5 percent of the average expected
pressure readings to be encountered during the field test. This is
particularly important under low pressure conditions.
6.4.2 Gauge used for yaw nulling. The differential pressure-
measuring device chosen for yaw nulling the probe during the wind tunnel
calibrations and field testing shall be bi-directional, i.e., capable of
reading both positive and negative differential pressures. If a
mechanical, bi-directional pressure gauge is chosen, it shall have a
full-scale range no greater than 2.6 cm (i.e., -1.3 to + 1.3 cm) [1 in.
H2O (i.e., -0.5 in. to + 0.5 in.)].
6.4.3 Devices for calibrating differential pressure-measuring
devices. A precision manometer (e.g., a U-tube, inclined, or inclined-
vertical manometer, or micromanometer) or NIST (National Institute of
Standards and Technology) traceable pressure source shall be used for
calibrating differential pressure-measuring devices. The device shall be
maintained under laboratory conditions or in a similar protected
environment (e.g., a climate-controlled trailer). It shall not be used
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in field tests. The precision manometer shall have a scale gradation of
0.3 mm H2O (0.01 in. H2O), or less, in the range
of 0 to 5.1 cm H2O (0 to 2 in. H2O) and 2.5 mm
H2O (0.1 in. H2O), or less, in the range of 5.1 to
25.4 cm H2O (2 to 10 in. H2O). The manometer shall
have manufacturer's documentation that it meets an accuracy
specification of at least 0.5 percent of full scale. The NIST-traceable
pressure source shall be recertified annually.
6.4.4 Devices used for post-test calibration check. A precision
manometer meeting the specifications in section 6.4.3, a pressure-
measuring device or pressure source with a documented calibration
traceable to NIST, or an equivalent device approved by the Administrator
shall be used for the post-test calibration check. The pressure-
measuring device shall have a readability equivalent to or greater than
the tested device. The pressure source shall be capable of generating
pressures between 50 and 90 percent of the range of the tested device
and known to within 1 percent of the full scale of
the tested device. The pressure source shall be recertified annually.
6.5 Data Display and Capture Devices. Electronic manometers (if
used) shall be coupled with a data display device (such as a digital
panel meter, personal computer display, or strip chart) that allows the
tester to observe and validate the pressure measurements taken during
testing. They shall also be connected to a data recorder (such as a data
logger or a personal computer with data capture software) that has the
ability to compute and retain the appropriate average value at each
traverse point, identified by collection time and traverse point.
6.6 Temperature Gauges. For field tests, a thermocouple or
resistance temperature detector (RTD) capable of measuring temperature
to within 3 [deg]C (5
[deg]F) of the stack or duct temperature shall be used. The thermocouple
shall be attached to the probe such that the sensor tip does not touch
any metal. The position of the thermocouple relative to the pressure
port face openings shall be in the same configuration as used for the
probe calibrations in the wind tunnel. Temperature gauges used for wind
tunnel calibrations shall be capable of measuring temperature to within
0.6 [deg]C (1 [deg]F) of the
temperature of the flowing gas stream in the wind tunnel.
6.7 Stack or Duct Static Pressure Measurement. The pressure-
measuring device used with the probe shall be as specified in section
6.4 of this method. The static tap of a standard (Prandtl type) pitot
tube or one leg of a Type S pitot tube with the face opening planes
positioned parallel to the gas flow may be used for this measurement.
Also acceptable is the pressure differential reading of P1-
Pbar from a five-hole prism-shaped 3-D probe, as specified in
section 6.1.1 of Method 2F (such as the Type DA or DAT probe), with the
P1 pressure port face opening positioned parallel to the gas
flow in the same manner as the Type S probe. However, the 3-D spherical
probe, as specified in section 6.1.2 of Method 2F, is unable to provide
this measurement and shall not be used to take static pressure
measurements. Static pressure measurement is further described in
section 8.11.
6.8 Barometer. Same as Method 2, section 2.5.
6.9 Gas Density Determination Equipment. Method 3 or 3A shall be
used to determine the dry molecular weight of the stack or duct gas.
Method 4 shall be used for moisture content determination and
computation of stack or duct gas wet molecular weight. Other methods may
be used, if approved by the Administrator.
6.10 Calibration Pitot Tube. Same as Method 2, section 2.7.
6.11 Wind Tunnel for Probe Calibration. Wind tunnels used to
calibrate velocity probes must meet the following design specifications.
6.11.1 Test section cross-sectional area. The flowing gas stream
shall be confined within a circular, rectangular, or elliptical duct.
The cross-sectional area of the tunnel must be large enough to ensure
fully developed flow in the presence of both the calibration pitot tube
and the tested probe. The calibration site, or ``test section,'' of the
wind tunnel shall have a minimum diameter of 30.5 cm (12 in.) for
circular or elliptical duct cross-sections or a minimum width of 30.5 cm
(12 in.) on the shorter side for rectangular cross-sections. Wind
tunnels shall meet the probe blockage provisions of this section and the
qualification requirements prescribed in section 10.1. The projected
area of the portion of the probe head, shaft, and attached devices
inside the wind tunnel during calibration shall represent no more than 2
percent of the cross-sectional area of the tunnel. If the pitot and/or
probe assembly blocks more than 2 percent of the cross-sectional area at
an insertion point only 4 inches inside the wind tunnel, the diameter of
the wind tunnel must be increased.
6.11.2 Velocity range and stability. The wind tunnel should be
capable of achieving and maintaining a constant and steady velocity
between 6.1 m/sec and 30.5 m/sec (20 ft/sec and 100 ft/sec) for the
entire calibration period for each selected calibration velocity. The
wind tunnel shall produce fully developed flow patterns that are stable
and parallel to the axis of the duct in the test section.
6.11.3 Flow profile at the calibration location. The wind tunnel
shall provide axial flow within the test section calibration location
(as defined in section 3.21). Yaw and pitch angles in the calibration
location shall be within 3[deg] of 0[deg]. The
procedure for determining that this requirement has been met is
described in section 10.1.2.
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6.11.4 Entry ports in the wind tunnel test section.
6.11.4.1 Port for tested probe. A port shall be constructed for the
tested probe. This port shall be located to allow the head of the tested
probe to be positioned within the wind tunnel calibration location (as
defined in section 3.21). The tested probe shall be able to be locked
into the 0[deg] pitch angle position. To facilitate alignment of the
probe during calibration, the test section should include a window
constructed of a transparent material to allow the tested probe to be
viewed.
6.11.4.2 Port for verification of axial flow. Depending on the
equipment selected to conduct the axial flow verification prescribed in
section 10.1.2, a second port, located 90[deg] from the entry port for
the tested probe, may be needed to allow verification that the gas flow
is parallel to the central axis of the test section. This port should be
located and constructed so as to allow one of the probes described in
section 10.1.2.2 to access the same test point(s) that are accessible
from the port described in section 6.11.4.1.
6.11.4.3 Port for calibration pitot tube. The calibration pitot tube
shall be used in the port for the tested probe or in a separate entry
port. In either case, all measurements with the calibration pitot tube
shall be made at the same point within the wind tunnel over the course
of a probe calibration. The measurement point for the calibration pitot
tube shall meet the same specifications for distance from the wall and
for axial flow as described in section 3.21 for the wind tunnel
calibration location.
7.0 Reagents and Standards [Reserved]
8.0 Sample Collection and Analysis
8.1 Equipment Inspection and Set Up
8.1.1 All 2-D and 3-D probes, differential pressure-measuring
devices, yaw angle-measuring devices, thermocouples, and barometers
shall have a current, valid calibration before being used in a field
test. (See sections 10.3.3, 10.3.4, and 10.5 through 10.10 for the
applicable calibration requirements.)
8.1.2 Before each field use of a Type S probe, perform a visual
inspection to verify the physical condition of the pitot tube. Record
the results of the inspection. If the face openings are noticeably
misaligned or there is visible damage to the face openings, the probe
shall not be used until repaired, the dimensional specifications
verified (according to the procedures in section 10.2.1), and the probe
recalibrated.
8.1.3 Before each field use of a 3-D probe, perform a visual
inspection to verify the physical condition of the probe head according
to the procedures in section 10.2 of Method 2F. Record the inspection
results on a form similar to Table 2F-1 presented in Method 2F. If there
is visible damage to the 3-D probe, the probe shall not be used until it
is recalibrated.
8.1.4 After verifying that the physical condition of the probe head
is acceptable, set up the apparatus using lengths of flexible tubing
that are as short as practicable. Surge tanks installed between the
probe and pressure-measuring device may be used to dampen pressure
fluctuations provided that an adequate measurement system response time
(see section 8.8) is maintained.
8.2 Horizontal Straightness Check. A horizontal straightness check
shall be performed before the start of each field test, except as
otherwise specified in this section. Secure the fully assembled probe
(including the probe head and all probe shaft extensions) in a
horizontal position using a stationary support at a point along the
probe shaft approximating the location of the stack or duct entry port
when the probe is sampling at the farthest traverse point from the stack
or duct wall. The probe shall be rotated to detect bends. Use an angle-
measuring device or trigonometry to determine the bend or sag between
the probe head and the secured end. (See Figure 2G-6.) Probes that are
bent or sag by more than 5[deg] shall not be used. Although this check
does not apply when the probe is used for a vertical traverse, care
should be taken to avoid the use of bent probes when conducting vertical
traverses. If the probe is constructed of a rigid steel material and
consists of a main probe without probe extensions, this check need only
be performed before the initial field use of the probe, when the probe
is recalibrated, when a change is made to the design or material of the
probe assembly, and when the probe becomes bent. With such probes, a
visual inspection shall be made of the fully assembled probe before each
field test to determine if a bend is visible. The probe shall be rotated
to detect bends. The inspection results shall be documented in the field
test report. If a bend in the probe is visible, the horizontal
straightness check shall be performed before the probe is used.
8.3 Rotational Position Check. Before each field test, and each time
an extension is added to the probe during a field test, a rotational
position check shall be performed on all manually operated probes
(except as noted in section 8.3.5 below) to ensure that, throughout
testing, the angle-measuring device is either: aligned to within 1[deg] of the rotational position of the reference
scribe line; or is affixed to the probe such that the rotational offset
of the device from the reference scribe line is known to within 1[deg]. This check shall consist of direct measurements
of the rotational positions of the reference scribe line and angle-
measuring device sufficient to verify that these specifications are met.
Annex A in section 18 of this method gives recommended procedures for
performing the rotational position check, and Table 2G-2
[[Page 95]]
gives an example data form. Procedures other than those recommended in
Annex A in section 18 may be used, provided they demonstrate whether the
alignment specification is met and are explained in detail in the field
test report.
8.3.1 Angle-measuring device rotational offset. The tester shall
maintain a record of the angle-measuring device rotational offset,
RADO, as defined in section 3.1. Note that RADO is
assigned a value of 0[deg] when the angle-measuring device is aligned to
within 1[deg] of the rotational position of the
reference scribe line. The RADO shall be used to determine
the yaw angle of flow in accordance with section 8.9.4.
8.3.2 Sign of angle-measuring device rotational offset. The sign of
RADO is positive when the angle-measuring device (as viewed
from the ``tail'' end of the probe) is positioned in a clockwise
direction from the reference scribe line and negative when the device is
positioned in a counterclockwise direction from the reference scribe
line.
8.3.3 Angle-measuring devices that can be independently adjusted
(e.g., by means of a set screw), after being locked into position on the
probe sheath, may be used. However, the RADO must also take
into account this adjustment.
8.3.4 Post-test check. If probe extensions remain attached to the
main probe throughout the field test, the rotational position check
shall be repeated, at a minimum, at the completion of the field test to
ensure that the angle-measuring device has remained within 2[deg] of its rotational position established prior to
testing. At the discretion of the tester, additional checks may be
conducted after completion of testing at any sample port or after any
test run. If the 2[deg] specification is not met,
all measurements made since the last successful rotational position
check must be repeated. section 18.1.1.3 of Annex A provides an example
procedure for performing the post-test check.
8.3.5 Exceptions.
8.3.5.1 A rotational position check need not be performed if, for
measurements taken at all velocity traverse points, the yaw angle-
measuring device is mounted and aligned directly on the reference scribe
line specified in sections 6.1.5.1 and 6.1.5.3 and no independent
adjustments, as described in section 8.3.3, are made to device's
rotational position.
8.3.5.2 If extensions are detached and re-attached to the probe
during a field test, a rotational position check need only be performed
the first time an extension is added to the probe, rather than each time
the extension is re-attached, if the probe extension is designed to be
locked into a mechanically fixed rotational position (e.g., through the
use of interlocking grooves), that can re-establish the initial
rotational position to within 1[deg].
8.4 Leak Checks. A pre-test leak check shall be conducted before
each field test. A post-test check shall be performed at the end of the
field test, but additional leak checks may be conducted after any test
run or group of test runs. The post-test check may also serve as the
pre-test check for the next group of test runs. If any leak check is
failed, all runs since the last passed leak check are invalid. While
performing the leak check procedures, also check each pressure device's
responsiveness to changes in pressure.
8.4.1 To perform the leak check on a Type S pitot tube, pressurize
the pitot impact opening until at least 7.6 cm H2O (3 in.
H2O) velocity pressure, or a pressure corresponding to
approximately 75 percent of the pressure device's measurement scale,
whichever is less, registers on the pressure device; then, close off the
impact opening. The pressure shall remain stable (2.5 mm H2O, 0.10 in.
H2O) for at least 15 seconds. Repeat this procedure for the
static pressure side, except use suction to obtain the required
pressure. Other leak-check procedures may be used, if approved by the
Administrator.
8.4.2 To perform the leak check on a 3-D probe, pressurize the
probe's impact (P1) opening until at least 7.6 cm
H2O (3 in. H2O) velocity pressure, or a pressure
corresponding to approximately 75 percent of the pressure device's
measurement scale, whichever is less, registers on the pressure device;
then, close off the impact opening. The pressure shall remain stable
(2.5 mm H2O, 0.10
in. H2O) for at least 15 seconds. Check the P2 and
P3 pressure ports in the same fashion. Other leak-check
procedures may be used, if approved by the Administrator.
8.5 Zeroing the Differential Pressure-measuring Device. Zero each
differential pressure-measuring device, including the device used for
yaw nulling, before each field test. At a minimum, check the zero after
each field test. A zero check may also be performed after any test run
or group of test runs. For fluid manometers and mechanical pressure
gauges (e.g., Magnehelic[Delta] gauges), the zero reading
shall not deviate from zero by more than 0.8 mm
H2O (0.03 in. H2O) or one
minor scale division, whichever is greater, between checks. For
electronic manometers, the zero reading shall not deviate from zero
between checks by more than: 0.3 mm H2O
(0.01 in. H2O), for full scales less
than or equal to 5.1 cm H2O (2.0 in. H2O); or
0.8 mm H2O (0.03
in. H2O), for full scales greater than 5.1 cm H2O
(2.0 in. H2O). (Note: If negative zero drift is not directly
readable, estimate the reading based on the position of the gauge oil in
the manometer or of the needle on the pressure gauge.) In addition, for
all pressure-measuring devices except those used exclusively for yaw
nulling, the zero
[[Page 96]]
reading shall not deviate from zero by more than 5 percent of the
average measured differential pressure at any distinct process condition
or load level. If any zero check is failed at a specific process
condition or load level, all runs conducted at that process condition or
load level since the last passed zero check are invalid.
8.6 Traverse Point Verification. The number and location of the
traverse points shall be selected based on Method 1 guidelines. The
stack or duct diameter and port nipple lengths, including any extension
of the port nipples into the stack or duct, shall be verified the first
time the test is performed; retain and use this information for
subsequent field tests, updating it as required. Physically measure the
stack or duct dimensions or use a calibrated laser device; do not use
engineering drawings of the stack or duct. The probe length necessary to
reach each traverse point shall be recorded to within 6.4 mm (\1/4\ in.) and, for manual
probes, marked on the probe sheath. In determining these lengths, the
tester shall take into account both the distance that the port flange
projects outside of the stack and the depth that any port nipple extends
into the gas stream. The resulting point positions shall reflect the
true distances from the inside wall of the stack or duct, so that when
the tester aligns any of the markings with the outside face of the stack
port, the probe's impact port shall be located at the appropriate
distance from the inside wall for the respective Method 1 traverse
point. Before beginning testing at a particular location, an out-of-
stack or duct verification shall be performed on each probe that will be
used to ensure that these position markings are correct. The distances
measured during the verification must agree with the previously
calculated distances to within \1/4\ in. For
manual probes, the traverse point positions shall be verified by
measuring the distance of each mark from the probe's impact pressure
port (the P1 port for a 3-D probe). A comparable out-of-stack
test shall be performed on automated probe systems. The probe shall be
extended to each of the prescribed traverse point positions. Then, the
accuracy of the positioning for each traverse point shall be verified by
measuring the distance between the port flange and the probe's impact
pressure port.
8.7 Probe Installation. Insert the probe into the test port. A solid
material shall be used to seal the port.
8.8 System Response Time. Determine the response time of the probe
measurement system. Insert and position the ``cold'' probe (at ambient
temperature and pressure) at any Method 1 traverse point. Read and
record the probe differential pressure, temperature, and elapsed time at
15-second intervals until stable readings for both pressure and
temperature are achieved. The response time is the longer of these two
elapsed times. Record the response time.
8.9 Sampling.
8.9.1 Yaw angle measurement protocol. With manual probes, yaw angle
measurements may be obtained in two alternative ways during the field
test, either by using a yaw angle-measuring device (e.g., digital
inclinometer) affixed to the probe, or using a protractor wheel and
pointer assembly. For horizontal traversing, either approach may be
used. For vertical traversing, i.e., when measuring from on top or into
the bottom of a horizontal duct, only the protractor wheel and pointer
assembly may be used. With automated probes, curve-fitting protocols may
be used to obtain yaw-angle measurements.
8.9.1.1 If a yaw angle-measuring device affixed to the probe is to
be used, lock the device on the probe sheath, aligning it either on the
reference scribe line or in the rotational offset position established
under section 8.3.1.
8.9.1.2 If a protractor wheel and pointer assembly is to be used,
follow the procedures in Annex B of this method.
8.9.1.3 Curve-fitting procedures. Curve-fitting routines sweep
through a range of yaw angles to create curves correlating pressure to
yaw position. To find the zero yaw position and the yaw angle of flow,
the curve found in the stack is computationally compared to a similar
curve that was previously generated under controlled conditions in a
wind tunnel. A probe system that uses a curve-fitting routine for
determining the yaw-null position of the probe head may be used,
provided that it is verified in a wind tunnel to be able to determine
the yaw angle of flow to within 1[deg].
8.9.1.4 Other yaw angle determination procedures. If approved by the
Administrator, other procedures for determining yaw angle may be used,
provided that they are verified in a wind tunnel to be able to perform
the yaw angle calibration procedure as described in section 10.5.
8.9.2 Sampling strategy. At each traverse point, first yaw-null the
probe, as described in section 8.9.3, below. Then, with the probe
oriented into the direction of flow, measure and record the yaw angle,
the differential pressure and the temperature at the traverse point,
after stable readings are achieved, in accordance with sections 8.9.4
and 8.9.5. At the start of testing in each port (i.e., after a probe has
been inserted into the flue gas stream), allow at least the response
time to elapse before beginning to take measurements at the first
traverse point accessed from that port. Provided that the probe is not
removed from the flue gas stream, measurements may be taken at
subsequent traverse points accessed from the same test port without
waiting again for the response time to elapse.
[[Page 97]]
8.9.3 Yaw-nulling procedure. In preparation for yaw angle
determination, the probe must first be yaw nulled. After positioning the
probe at the appropriate traverse point, perform the following
procedures.
8.9.3.1 For Type S probes, rotate the probe until a null
differential pressure reading is obtained. The direction of the probe
rotation shall be such that the thermocouple is located downstream of
the probe pressure ports at the yaw-null position. Rotate the probe
90[deg] back from the yaw-null position to orient the impact pressure
port into the direction of flow. Read and record the angle displayed by
the angle-measuring device.
8.9.3.2 For 3-D probes, rotate the probe until a null differential
pressure reading (the difference in pressures across the P2
and P3 pressure ports is zero, i.e., P2 =
P3) is indicated by the yaw angle pressure gauge. Read and
record the angle displayed by the angle-measuring device.
8.9.3.3 Sign of the measured angle. The angle displayed on the
angle-measuring device is considered positive when the probe's impact
pressure port (as viewed from the ``tail'' end of the probe) is oriented
in a clockwise rotational position relative to the stack or duct axis
and is considered negative when the probe's impact pressure port is
oriented in a counterclockwise rotational position (see Figure 2G-7).
8.9.4 Yaw angle determination. After performing the applicable yaw-
nulling procedure in section 8.9.3, determine the yaw angle of flow
according to one of the following procedures. Special care must be
observed to take into account the signs of the recorded angle reading
and all offsets.
8.9.4.1 Direct-reading. If all rotational offsets are zero or if the
angle-measuring device rotational offset (RADO) determined in
section 8.3 exactly compensates for the scribe line rotational offset
(RSLO) determined in section 10.5, then the magnitude of the
yaw angle is equal to the displayed angle-measuring device reading from
section 8.9.3.1 or 8.9.3.2. The algebraic sign of the yaw angle is
determined in accordance with section 8.9.3.3. [Note: Under certain
circumstances (e.g., testing of horizontal ducts) a 90[deg] adjustment
to the angle-measuring device readings may be necessary to obtain the
correct yaw angles.]
8.9.4.2 Compensation for rotational offsets during data reduction.
When the angle-measuring device rotational offset does not compensate
for reference scribe line rotational offset, the following procedure
shall be used to determine the yaw angle:
(a) Enter the reading indicated by the angle-measuring device from
section 8.9.3.1 or 8.9.3.2.
(b) Associate the proper algebraic sign from section 8.9.3.3 with
the reading in step (a).
(c) Subtract the reference scribe line rotational offset,
RSLO, from the reading in step (b).
(d) Subtract the angle-measuring device rotational offset,
RADO, if any, from the result obtained in step (c).
(e) The final result obtained in step (d) is the yaw angle of flow.
Note: It may be necessary to first apply a 90[deg] adjustment to the
reading in step (a), in order to obtain the correct yaw angle.
8.9.4.3 Record the yaw angle measurements on a form similar to Table
2G-3.
8.9.5 Impact velocity determination. Maintain the probe rotational
position established during the yaw angle determination. Then, begin
recording the pressure-measuring device readings. These pressure
measurements shall be taken over a sampling period of sufficiently long
duration to ensure representative readings at each traverse point. If
the pressure measurements are determined from visual readings of the
pressure device or display, allow sufficient time to observe the
pulsation in the readings to obtain a sight-weighted average, which is
then recorded manually. If an automated data acquisition system (e.g.,
data logger, computer-based data recorder, strip chart recorder) is used
to record the pressure measurements, obtain an integrated average of all
pressure readings at the traverse point. Stack or duct gas temperature
measurements shall be recorded, at a minimum, once at each traverse
point. Record all necessary data as shown in the example field data form
(Table 2G-3).
8.9.6 Alignment check. For manually operated probes, after the
required yaw angle and differential pressure and temperature
measurements have been made at each traverse point, verify (e.g., by
visual inspection) that the yaw angle-measuring device has remained in
proper alignment with the reference scribe line or with the rotational
offset position established in section 8.3. If, for a particular
traverse point, the angle-measuring device is found to be in proper
alignment, proceed to the next traverse point; otherwise, re-align the
device and repeat the angle and differential pressure measurements at
the traverse point. In the course of a traverse, if a mark used to
properly align the angle-measuring device (e.g., as described in section
18.1.1.1) cannot be located, re-establish the alignment mark before
proceeding with the traverse.
8.10 Probe Plugging. Periodically check for plugging of the pressure
ports by observing the responses on the pressure differential readouts.
Plugging causes erratic results or sluggish responses. Rotate the probe
to determine whether the readouts respond in the expected direction. If
plugging is detected, correct the problem and repeat the affected
measurements.
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8.11 Static Pressure. Measure the static pressure in the stack or
duct using the equipment described in section 6.7.
8.11.1 If a Type S probe is used for this measurement, position the
probe at or between any traverse point(s) and rotate the probe until a
null differential pressure reading is obtained. Disconnect the tubing
from one of the pressure ports; read and record the [Delta]P. For
pressure devices with one-directional scales, if a deflection in the
positive direction is noted with the negative side disconnected, then
the static pressure is positive. Likewise, if a deflection in the
positive direction is noted with the positive side disconnected, then
the static pressure is negative.
8.11.2 If a 3-D probe is used for this measurement, position the
probe at or between any traverse point(s) and rotate the probe until a
null differential pressure reading is obtained at P2-
P3. Rotate the probe 90[deg]. Disconnect the P2
pressure side of the probe and read the pressure P1-
Pbar and record as the static pressure. (Note: The spherical
probe, specified in section 6.1.2 of Method 2F, is unable to provide
this measurement and shall not be used to take static pressure
measurements.)
8.12 Atmospheric Pressure. Determine the atmospheric pressure at the
sampling elevation during each test run following the procedure
described in section 2.5 of Method 2.
8.13 Molecular Weight. Determine the stack or duct gas dry molecular
weight. For combustion processes or processes that emit essentially
CO2, O2, CO, and N2, use Method 3 or
3A. For processes emitting essentially air, an analysis need not be
conducted; use a dry molecular weight of 29.0. Other methods may be
used, if approved by the Administrator.
8.14 Moisture. Determine the moisture content of the stack gas using
Method 4 or equivalent.
8.15 Data Recording and Calculations. Record all required data on a
form similar to Table 2G-3.
8.15.1 2-D probe calibration coefficient. When a Type S pitot tube
is used in the field, the appropriate calibration coefficient as
determined in section 10.6 shall be used to perform velocity
calculations. For calibrated Type S pitot tubes, the A-side coefficient
shall be used when the A-side of the tube faces the flow, and the B-side
coefficient shall be used when the B-side faces the flow.
8.15.2 3-D calibration coefficient. When a 3-D probe is used to
collect data with this method, follow the provisions for the calibration
of 3-D probes in section 10.6 of Method 2F to obtain the appropriate
velocity calibration coefficient (F2 as derived using
Equation 2F-2 in Method 2F) corresponding to a pitch angle position of
0[deg].
8.15.3 Calculations. Calculate the yaw-adjusted velocity at each
traverse point using the equations presented in section 12.2. Calculate
the test run average stack gas velocity by finding the arithmetic
average of the point velocity results in accordance with sections 12.3
and 12.4, and calculate the stack gas volumetric flow rate in accordance
with section 12.5 or 12.6, as applicable.
9.0 Quality Control
9.1 Quality Control Activities. In conjunction with the yaw angle
determination and the pressure and temperature measurements specified in
section 8.9, the following quality control checks should be performed.
9.1.1 Range of the differential pressure gauge. In accordance with
the specifications in section 6.4, ensure that the proper differential
pressure gauge is being used for the range of [Delta]P values
encountered. If it is necessary to change to a more sensitive gauge,
replace the gauge with a gauge calibrated according to section 10.3.3,
perform the leak check described in section 8.4 and the zero check
described in section 8.5, and repeat the differential pressure and
temperature readings at each traverse point.
9.1.2 Horizontal stability check. For horizontal traverses of a
stack or duct, visually check that the probe shaft is maintained in a
horizontal position prior to taking a pressure reading. Periodically,
during a test run, the probe's horizontal stability should be verified
by placing a carpenter's level, a digital inclinometer, or other angle-
measuring device on the portion of the probe sheath that extends outside
of the test port. A comparable check should be performed by automated
systems.
10.0 Calibration
10.1 Wind Tunnel Qualification Checks. To qualify for use in
calibrating probes, a wind tunnel shall have the design features
specified in section 6.11 and satisfy the following qualification
criteria. The velocity pressure cross-check in section 10.1.1 and axial
flow verification in section 10.1.2 shall be performed before the
initial use of the wind tunnel and repeated immediately after any
alteration occurs in the wind tunnel's configuration, fans, interior
surfaces, straightening vanes, controls, or other properties that could
reasonably be expected to alter the flow pattern or velocity stability
in the tunnel. The owner or operator of a wind tunnel used to calibrate
probes according to this method shall maintain records documenting that
the wind tunnel meets the requirements of sections 10.1.1 and 10.1.2 and
shall provide these records to the Administrator upon request.
10.1.1 Velocity pressure cross-check. To verify that the wind tunnel
produces the same velocity at the tested probe head as at the
calibration pitot tube impact port, perform the following cross-check.
Take three
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differential pressure measurements at the fixed calibration pitot tube
location, using the calibration pitot tube specified in section 6.10,
and take three measurements with the calibration pitot tube at the wind
tunnel calibration location, as defined in section 3.21. Alternate the
measurements between the two positions. Perform this procedure at the
lowest and highest velocity settings at which the probes will be
calibrated. Record the values on a form similar to Table 2G-4. At each
velocity setting, the average velocity pressure obtained at the wind
tunnel calibration location shall be within 2
percent or 2.5 mm H2O (0.01 in. H2O), whichever is
less restrictive, of the average velocity pressure obtained at the fixed
calibration pitot tube location. This comparative check shall be
performed at 2.5-cm (1-in.), or smaller, intervals across the full
length, width, and depth (if applicable) of the wind tunnel calibration
location. If the criteria are not met at every tested point, the wind
tunnel calibration location must be redefined, so that acceptable
results are obtained at every point. Include the results of the velocity
pressure cross-check in the calibration data section of the field test
report. (See section 16.1.4.)
10.1.2 Axial flow verification. The following procedures shall be
performed to demonstrate that there is fully developed axial flow within
the wind tunnel calibration location and at the calibration pitot tube
location. Two options are available to conduct this check.
10.1.2.1 Using a calibrated 3-D probe. A probe that has been
previously calibrated in a wind tunnel with documented axial flow (as
defined in section 3.22) may be used to conduct this check. Insert the
calibrated 3-D probe into the wind tunnel test section using the tested
probe port. Following the procedures in sections 8.9 and 12.2 of Method
2F, determine the yaw and pitch angles at all the point(s) in the test
section where the velocity pressure cross-check, as specified in section
10.1.1, is performed. This includes all the points in the calibration
location and the point where the calibration pitot tube will be located.
Determine the yaw and pitch angles at each point. Repeat these
measurements at the highest and lowest velocities at which the probes
will be calibrated. Record the values on a form similar to Table 2G-5.
Each measured yaw and pitch angle shall be within 3[deg] of 0[deg]. Exceeding the limits indicates
unacceptable flow in the test section. Until the problem is corrected
and acceptable flow is verified by repetition of this procedure, the
wind tunnel shall not be used for calibration of probes. Include the
results of the axial flow verification in the calibration data section
of the field test report. (See section 16.1.4.)
10.1.2.2 Using alternative probes. Axial flow verification may be
performed using an uncalibrated prism-shaped 3-D probe (e.g., DA or DAT
probe) or an uncalibrated wedge probe. (Figure 2G-8 illustrates a
typical wedge probe.) This approach requires use of two ports: the
tested probe port and a second port located 90[deg] from the tested
probe port. Each port shall provide access to all the points within the
wind tunnel test section where the velocity pressure cross-check, as
specified in section 10.1.1, is conducted. The probe setup shall include
establishing a reference yaw-null position on the probe sheath to serve
as the location for installing the angle-measuring device. Physical
design features of the DA, DAT, and wedge probes are relied on to
determine the reference position. For the DA or DAT probe, this
reference position can be determined by setting a digital inclinometer
on the flat facet where the P1 pressure port is located and
then identifying the rotational position on the probe sheath where a
second angle-measuring device would give the same angle reading. The
reference position on a wedge probe shaft can be determined either
geometrically or by placing a digital inclinometer on each side of the
wedge and rotating the probe until equivalent readings are obtained.
With the latter approach, the reference position is the rotational
position on the probe sheath where an angle-measuring device would give
a reading of 0[deg]. After installation of the angle-measuring device in
the reference yaw-null position on the probe sheath, determine the yaw
angle from the tested port. Repeat this measurement using the 90[deg]
offset port, which provides the pitch angle of flow. Determine the yaw
and pitch angles at all the point(s) in the test section where the
velocity pressure cross-check, as specified in section 10.1.1, is
performed. This includes all the points in the wind tunnel calibration
location and the point where the calibration pitot tube will be located.
Perform this check at the highest and lowest velocities at which the
probes will be calibrated. Record the values on a form similar to Table
2G-5. Each measured yaw and pitch angle shall be within 3[deg] of 0[deg]. Exceeding the limits indicates
unacceptable flow in the test section. Until the problem is corrected
and acceptable flow is verified by repetition of this procedure, the
wind tunnel shall not be used for calibration of probes. Include the
results in the probe calibration report.
10.1.3 Wind tunnel audits.
10.1.3.1 Procedure. Upon the request of the Administrator, the owner
or operator of a wind tunnel shall calibrate a 2-D audit probe in
accordance with the procedures described in sections 10.3 through 10.6.
The calibration shall be performed at two velocities that encompass the
velocities typically used for this method at the facility. The resulting
calibration data shall be submitted to the Agency in an audit test
report. These results shall be
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compared by the Agency to reference calibrations of the audit probe at
the same velocity settings obtained at two different wind tunnels.
10.1.3.2 Acceptance criterion. The audited tunnel's calibration
coefficient is acceptable if it is within 3
percent of the reference calibrations obtained at each velocity setting
by one (or both) of the wind tunnels. If the acceptance criterion is not
met at each calibration velocity setting, the audited wind tunnel shall
not be used to calibrate probes for use under this method until the
problems are resolved and acceptable results are obtained upon
completion of a subsequent audit.
10.2 Probe Inspection.
10.2.1 Type S probe. Before each calibration of a Type S probe,
verify that one leg of the tube is permanently marked A, and the other,
B. Carefully examine the pitot tube from the top, side, and ends.
Measure the angles ([alpha]1, [alpha]2,
[beta]1, and [beta]2) and the dimensions (w and z)
illustrated in Figures 2-2 and 2-3 in Method 2. Also measure the
dimension A, as shown in the diagram in Table 2G-1, and the external
tubing diameter (dimension Dt, Figure 2-2b in Method 2). For
the purposes of this method, Dt shall be no less than 9.5 mm
(\3/8\ in.). The base-to-opening plane distances PA and
PB in Figure 2-3 of Method 2 shall be equal, and the
dimension A in Table 2G-1 should be between 2.10Dt and
3.00Dt. Record the inspection findings and probe measurements
on a form similar to Table CD2-1 of the ``Quality Assurance Handbook for
Air Pollution Measurement Systems: Volume III, Stationary Source-
Specific Methods'' (EPA/600/R-94/038c, September 1994). For reference,
this form is reproduced herein as Table 2G-1. The pitot tube shall not
be used under this method if it fails to meet the specifications in this
section and the alignment specifications in section 6.1.1. All Type S
probes used to collect data with this method shall be calibrated
according to the procedures outlined in sections 10.3 through 10.6
below. During calibration, each Type S pitot tube shall be configured in
the same manner as used, or planned to be used, during the field test,
including all components in the probe assembly (e.g., thermocouple,
probe sheath, sampling nozzle). Probe shaft extensions that do not
affect flow around the probe head need not be attached during
calibration.
10.2.2 3-D probe. If a 3-D probe is used to collect data with this
method, perform the pre-calibration inspection according to procedures
in Method 2F, section 10.2.
10.3 Pre-Calibration Procedures. Prior to calibration, a scribe line
shall have been placed on the probe in accordance with section 10.4. The
yaw angle and velocity calibration procedures shall not begin until the
pre-test requirements in sections 10.3.1 through 10.3.4 have been met.
10.3.1 Perform the horizontal straightness check described in
section 8.2 on the probe assembly that will be calibrated in the wind
tunnel.
10.3.2 Perform a leak check in accordance with section 8.4.
10.3.3 Except as noted in section 10.3.3.3, calibrate all
differential pressure-measuring devices to be used in the probe
calibrations, using the following procedures. At a minimum, calibrate
these devices on each day that probe calibrations are performed.
10.3.3.1 Procedure. Before each wind tunnel use, all differential
pressure-measuring devices shall be calibrated against the reference
device specified in section 6.4.3 using a common pressure source.
Perform the calibration at three reference pressures representing 30,
60, and 90 percent of the full-scale range of the pressure-measuring
device being calibrated. For an inclined-vertical manometer, perform
separate calibrations on the inclined and vertical portions of the
measurement scale, considering each portion of the scale to be a
separate full-scale range. [For example, for a manometer with a 0-to
2.5-cm H2O (0-to 1-in. H2O) inclined scale and a
2.5-to 12.7-cm H2O (1-to 5-in. H2O) vertical
scale, calibrate the inclined portion at 7.6, 15.2, and 22.9 mm
H2O (0.3, 0.6, and 0.9 in. H2O), and calibrate the
vertical portion at 3.8, 7.6, and 11.4 cm H2O (1.5, 3.0, and
4.5 in. H2O).] Alternatively, for the vertical portion of the
scale, use three evenly spaced reference pressures, one of which is
equal to or higher than the highest differential pressure expected in
field applications.
10.3.3.2 Acceptance criteria. At each pressure setting, the two
pressure readings made using the reference device and the pressure-
measuring device being calibrated shall agree to within 2 percent of full scale of the device being calibrated
or 0.5 mm H2O (0.02 in. H2O), whichever is less
restrictive. For an inclined-vertical manometer, these requirements
shall be met separately using the respective full-scale upper limits of
the inclined and vertical portions of the scale. Differential pressure-
measuring devices not meeting the 2 percent of
full scale or 0.5 mm H2O (0.02 in. H2O)
calibration requirement shall not be used.
10.3.3.3 Exceptions. Any precision manometer that meets the
specifications for a reference device in section 6.4.3 and that is not
used for field testing does not require calibration, but must be leveled
and zeroed before each wind tunnel use. Any pressure device used
exclusively for yaw nulling does not require calibration, but shall be
checked for responsiveness to rotation of the probe prior to each wind
tunnel use.
10.3.4 Calibrate digital inclinometers on each day of wind tunnel or
field testing
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(prior to beginning testing) using the following procedures. Calibrate
the inclinometer according to the manufacturer's calibration procedures.
In addition, use a triangular block (illustrated in Figure 2G-9) with a
known angle [theta], independently determined using a protractor or
equivalent device, between two adjacent sides to verify the inclinometer
readings. (Note: If other angle-measuring devices meeting the provisions
of section 6.2.3 are used in place of a digital inclinometer, comparable
calibration procedures shall be performed on such devices.) Secure the
triangular block in a fixed position. Place the inclinometer on one side
of the block (side A) to measure the angle of inclination
(R1). Repeat this measurement on the adjacent side of the
block (side B) using the inclinometer to obtain a second angle reading
(R2). The difference of the sum of the two readings from
180[deg] (i.e., 180[deg]-R1-R2) shall be within
2[deg] of the known angle, [theta].
10.4 Placement of Reference Scribe Line. Prior to the first
calibration of a probe, a line shall be permanently inscribed on the
main probe sheath to serve as a reference mark for determining yaw
angles. Annex C in section 18 of this method gives a guideline for
placement of the reference scribe line.
10.4.1 This reference scribe line shall meet the specifications in
sections 6.1.5.1 and 6.1.5.3 of this method. To verify that the
alignment specification in section 6.1.5.3 is met, secure the probe in a
horizontal position and measure the rotational angle of each scribe line
and scribe line segment using an angle-measuring device that meets the
specifications in section 6.2.1 or 6.2.3. For any scribe line that is
longer than 30.5 cm (12 in.), check the line's rotational position at
30.5-cm (12-in.) intervals. For each line segment that is 12 in. or less
in length, check the rotational position at the two endpoints of the
segment. To meet the alignment specification in section 6.1.5.3, the
minimum and maximum of all of the rotational angles that are measured
along the full length of main probe must not differ by more than 2[deg].
(Note: A short reference scribe line segment [e.g., 15.2 cm (6 in.) or
less in length] meeting the alignment specifications in section 6.1.5.3
is fully acceptable under this method. See section 18.1.1.1 of Annex A
for an example of a probe marking procedure, suitable for use with a
short reference scribe line.)
10.4.2 The scribe line should be placed on the probe first and then
its offset from the yaw-null position established (as specified in
section 10.5). The rotational position of the reference scribe line
relative to the yaw-null position of the probe, as determined by the yaw
angle calibration procedure in section 10.5, is the reference scribe
line rotational offset, RSLO. The reference scribe line
rotational offset shall be recorded and retained as part of the probe's
calibration record.
10.4.3 Scribe line for automated probes. A scribe line may not be
necessary for an automated probe system if a reference rotational
position of the probe is built into the probe system design. For such
systems, a ``flat'' (or comparable, clearly identifiable physical
characteristic) should be provided on the probe casing or flange plate
to ensure that the reference position of the probe assembly remains in a
vertical or horizontal position. The rotational offset of the flat (or
comparable, clearly identifiable physical characteristic) needed to
orient the reference position of the probe assembly shall be recorded
and maintained as part of the automated probe system's specifications.
10.5 Yaw Angle Calibration Procedure. For each probe used to measure
yaw angles with this method, a calibration procedure shall be performed
in a wind tunnel meeting the specifications in section 10.1 to determine
the rotational position of the reference scribe line relative to the
probe's yaw-null position. This procedure shall be performed on the main
probe with all devices that will be attached to the main probe in the
field [such as thermocouples, resistance temperature detectors (RTDs),
or sampling nozzles] that may affect the flow around the probe head.
Probe shaft extensions that do not affect flow around the probe head
need not be attached during calibration. At a minimum, this procedure
shall include the following steps.
10.5.1 Align and lock the angle-measuring device on the reference
scribe line. If a marking procedure (such as described in section
18.1.1.1) is used, align the angle-measuring device on a mark within
1[deg] of the rotational position of the reference
scribe line. Lock the angle-measuring device onto the probe sheath at
this position.
10.5.2 Zero the pressure-measuring device used for yaw nulling.
10.5.3 Insert the probe assembly into the wind tunnel through the
entry port, positioning the probe's impact port at the calibration
location. Check the responsiveness of the pressure-measurement device to
probe rotation, taking corrective action if the response is
unacceptable.
10.5.4 Ensure that the probe is in a horizontal position, using a
carpenter's level.
10.5.5 Rotate the probe either clockwise or counterclockwise until a
yaw null [zero [Delta]P for a Type S probe or zero (P2-
P3) for a 3-D probe] is obtained. If using a Type S probe
with an attached thermocouple, the direction of the probe rotation shall
be such that the thermocouple is located downstream of the probe
pressure ports at the yaw-null position.
10.5.6 Use the reading displayed by the angle-measuring device at
the yaw-null position to determine the magnitude of the reference scribe
line rotational offset, RSLO, as defined in section 3.15.
Annex D in section 18
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of this method gives a recommended procedure for determining the
magnitude of RSLO with a digital inclinometer and a second
procedure for determining the magnitude of RSLO with a
protractor wheel and pointer device. Table 2G-6 gives an example data
form and Table 2G-7 is a look-up table with the recommended procedure.
Procedures other than those recommended in Annex D in section 18 may be
used, if they can determine RSLO to within 1[deg] and are
explained in detail in the field test report. The algebraic sign of
RSLO will either be positive if the rotational position of
the reference scribe line (as viewed from the ``tail'' end of the probe)
is clockwise, or negative, if counterclockwise with respect to the
probe's yaw-null position. (This is illustrated in Figure 2G-10.)
10.5.7 The steps in sections 10.5.3 through 10.5.6 shall be
performed twice at each of the velocities at which the probe will be
calibrated (in accordance with section 10.6). Record the values of
RSLO.
10.5.8 The average of all of the RSLO values shall be
documented as the reference scribe line rotational offset for the probe.
10.5.9 Use of reference scribe line offset. The reference scribe
line rotational offset shall be used to determine the yaw angle of flow
in accordance with section 8.9.4.
10.6 Velocity Calibration Procedure. When a 3-D probe is used under
this method, follow the provisions for the calibration of 3-D probes in
section 10.6 of Method 2F to obtain the necessary velocity calibration
coefficients (F2 as derived using Equation 2F-2 in Method 2F)
corresponding to a pitch angle position of 0[deg]. The following
procedure applies to Type S probes. This procedure shall be performed on
the main probe and all devices that will be attached to the main probe
in the field (e.g., thermocouples, RTDs, sampling nozzles) that may
affect the flow around the probe head. Probe shaft extensions that do
not affect flow around the probe head need not be attached during
calibration. (Note: If a sampling nozzle is part of the assembly, two
additional requirements must be satisfied before proceeding. The
distance between the nozzle and the pitot tube shall meet the minimum
spacing requirement prescribed in Method 2, and a wind tunnel
demonstration shall be performed that shows the probe's ability to yaw
null is not impaired when the nozzle is drawing sample.) To obtain
velocity calibration coefficient(s) for the tested probe, proceed as
follows.
10.6.1 Calibration velocities. The tester may calibrate the probe at
two nominal wind tunnel velocity settings of 18.3 m/sec and 27.4 m/sec
(60 ft/sec and 90 ft/sec) and average the results of these calibrations,
as described in sections 10.6.12 through 10.6.14, in order to generate
the calibration coefficient, Cp. If this option is selected,
this calibration coefficient may be used for all field applications
where the velocities are 9.1 m/sec (30 ft/sec) or greater.
Alternatively, the tester may customize the probe calibration for a
particular field test application (or for a series of applications),
based on the expected average velocity(ies) at the test site(s). If this
option is selected, generate the calibration coefficients by calibrating
the probe at two nominal wind tunnel velocity settings, one of which is
less than or equal to and the other greater than or equal to the
expected average velocity(ies) for the field application(s), and average
the results as described in sections 10.6.12 through 10.6.14. Whichever
calibration option is selected, the probe calibration coefficient(s)
obtained at the two nominal calibration velocities shall meet the
conditions specified in sections 10.6.12 through 10.6.14.
10.6.2 Connect the tested probe and calibration pitot tube to their
respective pressure-measuring devices. Zero the pressure-measuring
devices. Inspect and leak-check all pitot lines; repair or replace them,
if necessary. Turn on the fan, and allow the wind tunnel air flow to
stabilize at the first of the selected nominal velocity settings.
10.6.3 Position the calibration pitot tube at its measurement
location (determined as outlined in section 6.11.4.3), and align the
tube so that its tip is pointed directly into the flow. Ensure that the
entry port surrounding the tube is properly sealed. The calibration
pitot tube may either remain in the wind tunnel throughout the
calibration, or be removed from the wind tunnel while measurements are
taken with the probe being calibrated.
10.6.4 Check the zero setting of each pressure-measuring device.
10.6.5 Insert the tested probe into the wind tunnel and align it so
that the designated pressure port (e.g., either the A-side or B-side of
a Type S probe) is pointed directly into the flow and is positioned
within the wind tunnel calibration location (as defined in section
3.21). Secure the probe at the 0[deg] pitch angle position. Ensure that
the entry port surrounding the probe is properly sealed.
10.6.6 Read the differential pressure from the calibration pitot
tube ([Delta]Pstd), and record its value. Read the barometric
pressure to within 2.5 mm Hg (0.1 in. Hg) and the temperature in the wind tunnel to
within 0.6 [deg]C (1 [deg]F). Record these values on a data form similar
to Table 2G-8. Record the rotational speed of the fan or indicator of
wind tunnel velocity control (damper setting, variac rheostat, etc.) and
make no adjustment to fan speed or wind tunnel velocity control between
this observation and the Type S probe reading.
10.6.7 After the tested probe's differential pressure gauges have
had sufficient time to stabilize, yaw null the probe (and then rotate it
back 90[deg] for Type S probes), then obtain the differential pressure
reading ([Delta]P). Record
[[Page 103]]
the yaw angle and differential pressure readings.
10.6.8 Take paired differential pressure measurements with the
calibration pitot tube and tested probe (according to sections 10.6.6
and 10.6.7). The paired measurements in each replicate can be made
either simultaneously (i.e., with both probes in the wind tunnel) or by
alternating the measurements of the two probes (i.e., with only one
probe at a time in the wind tunnel). Adjustments made to the fan speed
or other changes to the system designed to change the air flow velocity
of the wind tunnel between observation of the calibration pitot tube
([Delta]Pstd) and the Type S pitot tube invalidates the
reading and the observation must be repeated.
10.6.9 Repeat the steps in sections 10.6.6 through 10.6.8 at the
same nominal velocity setting until three pairs of [Delta]P readings
have been obtained from the calibration pitot tube and the tested probe.
10.6.10 Repeat the steps in sections 10.6.6 through 10.6.9 above for
the A-side and B-side of the Type S pitot tube. For a probe assembly
constructed such that its pitot tube is always used in the same
orientation, only one side of the pitot tube need be calibrated (the
side that will face the flow). However, the pitot tube must still meet
the alignment and dimension specifications in section 6.1.1 and must
have an average deviation ([sigma]) value of 0.01 or less as provided in
section 10.6.12.4.
10.6.11 Repeat the calibration procedures in sections 10.6.6 through
10.6.10 at the second selected nominal wind tunnel velocity setting.
10.6.12 Perform the following calculations separately on the A-side
and B-side values.
10.6.12.1 Calculate a Cp value for each of the three
replicates performed at the lower velocity setting where the
calibrations were performed using Equation 2-2 in section 4.1.4 of
Method 2.
10.6.12.2 Calculate the arithmetic average, Cp(avg-low),
of the three Cp values.
10.6.12.3 Calculate the deviation of each of the three individual
values of Cp from the A-side average Cp(avg-low)
value using Equation 2-3 in Method 2.
10.6.12.4 Calculate the average deviation ([sigma]) of the three
individual Cp values from Cp(avg-low) using
Equation 2-4 in Method 2. Use the Type S pitot tube only if the values
of [sigma] (side A) and [sigma] (side B) are less than or equal to 0.01.
If both A-side and B-side calibration coefficients are calculated, the
absolute value of the difference between Cp(avg-low) (side A)
and Cp(avg-low) (side B) must not exceed 0.01.
10.6.13 Repeat the calculations in section 10.6.12 using the data
obtained at the higher velocity setting to derive the arithmetic
Cp values at the higher velocity setting,
Cp(avg-high), and to determine whether the conditions in
10.6.12.4 are met by both the A-side and B-side calibrations at this
velocity setting.
10.6.14 Use equation 2G-1 to calculate the percent difference of the
averaged Cp values at the two calibration velocities.
[GRAPHIC] [TIFF OMITTED] TR14MY99.062
The percent difference between the averaged Cp values shall
not exceed 3 percent. If the specification is met,
average the A-side values of Cp(avg-low) and
Cp(avg-high) to produce a single A-side calibration
coefficient, Cp. Repeat for the B-side values if calibrations
were performed on that side of the pitot. If the specification is not
met, make necessary adjustments in the selected velocity settings and
repeat the calibration procedure until acceptable results are obtained.
10.6.15 If the two nominal velocities used in the calibration were
18.3 and 27.4 m/sec (60 and 90 ft/sec), the average Cp from
section 10.6.14 is applicable to all velocities 9.1 m/sec (30 ft/sec) or
greater. If two other nominal velocities were used in the calibration,
the resulting average Cp value shall be applicable only in
situations where the velocity calculated using the calibration
coefficient is neither less than the lower nominal velocity nor greater
than the higher nominal velocity.
10.7 Recalibration. Recalibrate the probe using the procedures in
section 10 either within 12 months of its first field use after its most
recent calibration or after 10 field tests (as defined in section 3.3),
whichever occurs later. In addition, whenever there is visible damage to
the probe head, the probe shall be recalibrated before it is used again.
10.8 Calibration of pressure-measuring devices used in the field.
Before its initial use in a field test, calibrate each pressure-
measuring device (except those used exclusively for yaw nulling) using
the three-point calibration procedure described in section 10.3.3. The
device shall be recalibrated according to the procedure in section
10.3.3 no later than 90 days after its first field use following its
most recent calibration. At the discretion of the tester, more frequent
calibrations (e.g.,
[[Page 104]]
after a field test) may be performed. No adjustments, other than
adjustments to the zero setting, shall be made to the device between
calibrations.
10.8.1 Post-test calibration check. A single-point calibration check
shall be performed on each pressure-measuring device after completion of
each field test. At the discretion of the tester, more frequent single-
point calibration checks (e.g., after one or more field test runs) may
be performed. It is recommended that the post-test check be performed
before leaving the field test site. The check shall be performed at a
pressure between 50 and 90 percent of full scale by taking a common
pressure reading with the tested probe and a reference pressure-
measuring device (as described in section 6.4.4) or by challenging the
tested device with a reference pressure source (as described in section
6.4.4) or by performing an equivalent check using a reference device
approved by the Administrator.
10.8.2 Acceptance criterion. At the selected pressure setting, the
pressure readings made using the reference device and the tested device
shall agree to within 3 percent of full scale of
the tested device or 0.8 mm H2O (0.03 in. H2O),
whichever is less restrictive. If this specification is met, the test
data collected during the field test are valid. If the specification is
not met, all test data collected since the last successful calibration
or calibration check are invalid and shall be repeated using a pressure-
measuring device with a current, valid calibration. Any device that
fails the calibration check shall not be used in a field test until a
successful recalibration is performed according to the procedures in
section 10.3.3.
10.9 Temperature Gauges. Same as Method 2, section 4.3. The
alternative thermocouple calibration procedures outlined in Emission
Measurement Center (EMC) Approved Alternative Method (ALT-011)
``Alternative Method 2 Thermocouple Calibration Procedure'' may be
performed. Temperature gauges shall be calibrated no more than 30 days
prior to the start of a field test or series of field tests and
recalibrated no more than 30 days after completion of a field test or
series of field tests.
10.10 Barometer. Same as Method 2, section 4.4. The barometer shall
be calibrated no more than 30 days prior to the start of a field test or
series of field tests.
11.0 Analytical Procedure
Sample collection and analysis are concurrent for this method (see
section 8.0).
12.0 Data Analysis and Calculations
These calculations use the measured yaw angle and the differential
pressure and temperature measurements at individual traverse points to
derive the near-axial flue gas velocity (va(i)) at each of
those points. The near-axial velocity values at all traverse points that
comprise a full stack or duct traverse are then averaged to obtain the
average near-axial stack or duct gas velocity (va(avg)).
12.1 Nomenclature
A = Cross-sectional area of stack or duct at the test port location,
m\2\ (ft \2\).
Bws = Water vapor in the gas stream (from Method 4 or
alternative), proportion by volume.
Cp = Pitot tube calibration coefficient, dimensionless.
F2(i) = 3-D probe velocity coefficient at 0 pitch, applicable
at traverse point i.
Kp = Pitot tube constant,
[GRAPHIC] [TIFF OMITTED] TR14MY99.063
for the metric system, and
[GRAPHIC] [TIFF OMITTED] TR14MY99.064
for the English system.
Md = Molecular weight of stack or duct gas, dry basis (see
section 8.13), g/g-mole (lb/lb-mole).
Ms = Molecular weight of stack or duct gas, wet basis, g/g-
mole (lb/lb-mole).
[GRAPHIC] [TIFF OMITTED] TR14MY99.065
Pbar = Barometric pressure at velocity measurement site, mm
Hg (in. Hg).
Pg = Stack or duct static pressure, mm H2O (in.
H2O).
Ps = Absolute stack or duct pressure, mm Hg (in. Hg),
[GRAPHIC] [TIFF OMITTED] TR14MY99.066
Pstd = Standard absolute pressure, 760 mm Hg (29.92 in. Hg).
13.6 = Conversion from mm H2O (in. H2O) to mm Hg
(in. Hg).
Qsd = Average dry-basis volumetric stack or duct gas flow
rate corrected to standard conditions, dscm/hr (dscf/hr).
Qsw = Average wet-basis volumetric stack or duct gas flow
rate corrected to standard conditions, wscm/hr (wscf/hr).
ts(i) = Stack or duct temperature, [deg]C ([deg]F), at
traverse point i.
Ts(i) = Absolute stack or duct temperature, [deg]K ([deg]R),
at traverse point i.
[GRAPHIC] [TIFF OMITTED] TR14MY99.067
for the metric system, and
[[Page 105]]
[GRAPHIC] [TIFF OMITTED] TR14MY99.068
for the English system.
Ts(avg) = Average absolute stack or duct gas temperature
across all traverse points.
Tstd = Standard absolute temperature, 293 [deg]K (528
[deg]R).
va(i) = Measured stack or duct gas impact velocity, m/sec
(ft/sec), at traverse point i.
va(avg) = Average near-axial stack or duct gas velocity, m/
sec (ft/sec) across all traverse points.
[Delta]Pi = Velocity head (differential pressure) of stack or
duct gas, mm H2O (in. H2O), applicable
at traverse point i.
(P1-P2) = Velocity head (differential pressure) of
stack or duct gas measured by a 3-D probe, mm H2O
(in. H2O), applicable at traverse point i.
3,600 = Conversion factor, sec/hr.
18.0 = Molecular weight of water, g/g-mole (lb/lb-mole).
[theta]y(i) = Yaw angle of the flow velocity vector, at
traverse point i.
n = Number of traverse points.
12.2 Traverse Point Velocity Calculations. Perform the following
calculations from the measurements obtained at each traverse point.
12.2.1 Selection of calibration coefficient. Select the calibration
coefficient as described in section 10.6.1.
12.2.2 Near-axial traverse point velocity. When using a Type S
probe, use the following equation to calculate the traverse point near-
axial velocity (va(i)) from the differential pressure
([Delta]Pi), yaw angle ([theta]y(i)), absolute
stack or duct standard temperature (Ts(i)) measured at
traverse point i, the absolute stack or duct pressure (Ps),
and molecular weight (Ms).
[GRAPHIC] [TIFF OMITTED] TR14MY99.069
Use the following equation when using a 3-D probe.
[GRAPHIC] [TIFF OMITTED] TR14MY99.070
12.2.3 Handling multiple measurements at a traverse point. For
pressure or temperature devices that take multiple measurements at a
traverse point, the multiple measurements (or where applicable, their
square roots) may first be averaged and the resulting average values
used in the equations above. Alternatively, the individual measurements
may be used in the equations above and the resulting calculated values
may then be averaged to obtain a single traverse point value. With
either approach, all of the individual measurements recorded at a
traverse point must be used in calculating the applicable traverse point
value.
12.3 Average Near-Axial Velocity in Stack or Duct. Use the reported
traverse point near-axial velocity in the following equation.
[GRAPHIC] [TIFF OMITTED] TR14MY99.071
12.4 Acceptability of Results. The acceptability provisions in
section 12.4 of Method 2F apply to 3-D probes used under Method 2G. The
following provisions apply to Type S probes. For Type S probes, the test
results are acceptable and the calculated value of va(avg)
may be reported as the average near-axial velocity for the test run if
the conditions in either section 12.4.1 or 12.4.2 are met.
12.4.1 The average calibration coefficient Cp used in
Equation 2G-6 was generated at nominal velocities of 18.3 and 27.4 m/sec
(60 and 90 ft/sec) and the value of va(avg) calculated using
Equation 2G-8 is greater than or equal to 9.1 m/sec (30 ft/sec).
12.4.2 The average calibration coefficient Cp used in
Equation 2G-6 was generated at nominal velocities other than 18.3 or
27.4 m/
[[Page 106]]
sec (60 or 90 ft/sec) and the value of va(avg) calculated
using Equation 2G-8 is greater than or equal to the lower nominal
velocity and less than or equal to the higher nominal velocity used to
derive the average Cp.
12.4.3 If the conditions in neither section 12.4.1 nor section
12.4.2 are met, the test results obtained from Equation 2G-8 are not
acceptable, and the steps in sections 12.2 and 12.3 must be repeated
using an average calibration coefficient Cp that satisfies
the conditions in section 12.4.1 or 12.4.2.
12.5 Average Gas Volumetric Flow Rate in Stack or Duct (Wet Basis).
Use the following equation to compute the average volumetric flow rate
on a wet basis.
[GRAPHIC] [TIFF OMITTED] TR14MY99.072
12.6 Average Gas Volumetric Flow Rate in Stack or Duct (Dry Basis).
Use the following equation to compute the average volumetric flow rate
on a dry basis.
[GRAPHIC] [TIFF OMITTED] TR14MY99.073
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Reporting.
16.1 Field Test Reports. Field test reports shall be submitted to
the Agency according to applicable regulatory requirements. Field test
reports should, at a minimum, include the following elements.
16.1.1 Description of the source. This should include the name and
location of the test site, descriptions of the process tested, a
description of the combustion source, an accurate diagram of stack or
duct cross-sectional area at the test site showing the dimensions of the
stack or duct, the location of the test ports, and traverse point
locations and identification numbers or codes. It should also include a
description and diagram of the stack or duct layout, showing the
distance of the test location from the nearest upstream and downstream
disturbances and all structural elements (including breachings, baffles,
fans, straighteners, etc.) affecting the flow pattern. If the source and
test location descriptions have been previously submitted to the Agency
in a document (e.g., a monitoring plan or test plan), referencing the
document in lieu of including this information in the field test report
is acceptable.
16.1.2 Field test procedures. These should include a description of
test equipment and test procedures. Testing conventions, such as
traverse point numbering and measurement sequence (e.g., sampling from
center to wall, or wall to center), should be clearly stated. Test port
identification and directional reference for each test port should be
included on the appropriate field test data sheets.
16.1.3 Field test data.
16.1.3.1 Summary of results. This summary should include the dates
and times of testing, and the average near-axial gas velocity and the
average flue gas volumetric flow results for each run and tested
condition.
16.1.3.2 Test data. The following values for each traverse point
should be recorded and reported:
(a) Differential pressure at traverse point i ([Delta]Pi)
(b) Stack or duct temperature at traverse point i (ts(i))
(c) Absolute stack or duct temperature at traverse point i
(Ts(i))
(d) Yaw angle at traverse point i ([theta]y(i))
(e) Stack gas near-axial velocity at traverse point i
(va(i))
16.1.3.3 The following values should be reported once per run:
(a) Water vapor in the gas stream (from Method 4 or alternative),
proportion by volume (Bws), measured at the frequency
specified in the applicable regulation
(b) Molecular weight of stack or duct gas, dry basis (Md)
(c) Molecular weight of stack or duct gas, wet basis (Ms)
(d) Stack or duct static pressure (Pg)
(e) Absolute stack or duct pressure (Ps)
(f) Carbon dioxide concentration in the flue gas, dry basis
(%d CO2)
[[Page 107]]
(g) Oxygen concentration in the flue gas, dry basis (%d
O2)
(h) Average near-axial stack or duct gas velocity
(va(avg)) across all traverse points
(i) Gas volumetric flow rate corrected to standard conditions, dry
or wet basis as required by the applicable regulation (Qsd or
Qsw)
16.1.3.4 The following should be reported once per complete set of
test runs:
(a) Cross-sectional area of stack or duct at the test location (A)
(b) Pitot tube calibration coefficient (Cp)
(c) Measurement system response time (sec)
(d) Barometric pressure at measurement site (Pbar)
16.1.4 Calibration data. The field test report should include
calibration data for all probes and test equipment used in the field
test. At a minimum, the probe calibration data reported to the Agency
should include the following:
(a) Date of calibration
(b) Probe type
(c) Probe identification number(s) or code(s)
(d) Probe inspection sheets
(e) Pressure measurements and calculations used to obtain
calibration coefficients in accordance with section 10.6 of this method
(f) Description and diagram of wind tunnel used for the calibration,
including dimensions of cross-sectional area and position and size of
the test section
(g) Documentation of wind tunnel qualification tests performed in
accordance with section 10.1 of this method
16.1.5 Quality assurance. Specific quality assurance and quality
control procedures used during the test should be described.
17.0 Bibliography.
(1) 40 CFR Part 60, Appendix A, Method 1--Sample and velocity
traverses for stationary sources.
(2) 40 CFR Part 60, Appendix A, Method 2--Determination of stack gas
velocity and volumetric flow rate (Type S pitot tube) .
(3) 40 CFR Part 60, Appendix A, Method 2F--Determination of stack
gas velocity and volumetric flow rate with three-dimensional probes.
(4) 40 CFR Part 60, Appendix A, Method 2H--Determination of stack
gas velocity taking into account velocity decay near the stack wall.
(5) 40 CFR Part 60, Appendix A, Method 3--Gas analysis for carbon
dioxide, oxygen, excess air, and dry molecular weight.
(6) 40 CFR Part 60, Appendix A, Method 3A--Determination of oxygen
and carbon dioxide concentrations in emissions from stationary sources
(instrumental analyzer procedure).
(7) 40 CFR Part 60, Appendix A, Method 4--Determination of moisture
content in stack gases.
(8) Emission Measurement Center (EMC) Approved Alternative Method
(ALT-011) ``Alternative Method 2 Thermocouple Calibration Procedure.''
(9) Electric Power Research Institute, Interim Report EPRI TR-
106698, ``Flue Gas Flow Rate Measurement Errors,'' June 1996.
(10) Electric Power Research Institute, Final Report EPRI TR-108110,
``Evaluation of Heat Rate Discrepancy from Continuous Emission
Monitoring Systems,'' August 1997.
(11) Fossil Energy Research Corporation, Final Report, ``Velocity
Probe Tests in Non-axial Flow Fields,'' November 1998, Prepared for the
U.S. Environmental Protection Agency.
(12) Fossil Energy Research Corporation, ``Additional Swirl Tunnel
Tests: E-DAT and T-DAT Probes,'' February 24, 1999, Technical Memorandum
Prepared for U.S. Environmental Protection Agency, P.O. No. 7W-1193-
NALX.
(13) Massachusetts Institute of Technology, Report WBWT-TR-1317,
``Calibration of Eight Wind Speed Probes Over a Reynolds Number Range of
46,000 to 725,000 Per Foot, Text and Summary Plots,'' Plus appendices,
October 15, 1998, Prepared for The Cadmus Group, Inc.
(14) National Institute of Standards and Technology, Special
Publication 250, ``NIST Calibration Services Users Guide 1991,'' Revised
October 1991, U.S. Department of Commerce, p. 2.
(15) National Institute of Standards and Technology, 1998, ``Report
of Special Test of Air Speed Instrumentation, Four Prandtl Probes, Four
S-Type Probes, Four French Probes, Four Modified Kiel Probes,'' Prepared
for the U.S. Environmental Protection Agency under IAG DW13938432-01-0.
(16) National Institute of Standards and Technology, 1998, ``Report
of Special Test of Air Speed In-strumentation, Five Autoprobes,''
Prepared for the U.S. Environmental Protection Agency under IAG
DW13938432-01-0.
(17) National Institute of Standards and Technology, 1998, ``Report
of Special Test of Air Speed Instrumentation, Eight Spherical Probes,''
Prepared for the U.S. Environmental Protection Agency under IAG
DW13938432-01-0.
(18) National Institute of Standards and Technology, 1998, ``Report
of Special Test of Air Speed Instrumentation, Four DAT Probes, ``
Prepared for the U.S. Environmental Protection Agency under IAG
DW13938432-01-0.
(19) Norfleet, S.K., ``An Evaluation of Wall Effects on Stack Flow
Velocities and Related Overestimation Bias in EPA's Stack
[[Page 108]]
Flow Reference Methods,'' EPRI CEMS User's Group Meeting, New Orleans,
Louisiana, May 13-15, 1998.
(20) Page, J.J., E.A. Potts, and R.T. Shigehara, ``3-D Pitot Tube
Calibration Study,'' EPA Contract No. 68D10009, Work Assignment No. I-
121, March 11, 1993.
(21) Shigehara, R.T., W.F. Todd, and W.S. Smith, ``Significance of
Errors in Stack Sampling Measurements,'' Presented at the Annual Meeting
of the Air Pollution Control Association, St. Louis, Missouri, June
1419, 1970.
(22) The Cadmus Group, Inc., May 1999, ``EPA Flow Reference Method
Testing and Analysis: Findings Report,'' EPA/430-R-99-009.
(23) The Cadmus Group, Inc., 1998, ``EPA Flow Reference Method
Testing and Analysis: Data Report, Texas Utilities, DeCordova Steam
Electric Station, Volume I: Test Description and Appendix A (Data
Distribution Package),'' EPA/430-R-98-015a.
(24) The Cadmus Group, Inc., 1998, ``EPA Flow Reference Method
Testing and Analysis: Data Report, Texas Utilities, Lake Hubbard Steam
Electric Station, Volume I: Test Description and Appendix A (Data
Distribution Package),'' EPA/430-R-98-017a.
(25) The Cadmus Group, Inc., 1998, ``EPA Flow Reference Method
Testing and Analysis: Data Report, Pennsylvania Electric Co., G.P.U.
Genco Homer City Station: Unit 1, Volume I: Test Description and
Appendix A (Data Distribution Package),'' EPA/430-R-98-018a.
(26) The Cadmus Group, Inc., 1997, ``EPA Flow Reference Method
Testing and Analysis: Wind Tunnel Experimental Results,'' EPA/430-R-97-
013.
18.0 Annexes
Annex A, C, and D describe recommended procedures for meeting
certain provisions in sections 8.3, 10.4, and 10.5 of this method. Annex
B describes procedures to be followed when using the protractor wheel
and pointer assembly to measure yaw angles, as provided under section
8.9.1.
18.1 Annex A--Rotational Position Check. The following are
recommended procedures that may be used to satisfy the rotational
position check requirements of section 8.3 of this method and to
determine the angle-measuring device rotational offset
(RADO).
18.1.1 Rotational position check with probe outside stack. Where
physical constraints at the sampling location allow full assembly of the
probe outside the stack and insertion into the test port, the following
procedures should be performed before the start of testing. Two angle-
measuring devices that meet the specifications in section 6.2.1 or 6.2.3
are required for the rotational position check. An angle measuring
device whose position can be independently adjusted (e.g., by means of a
set screw) after being locked into position on the probe sheath shall
not be used for this check unless the independent adjustment is set so
that the device performs exactly like a device without the capability
for independent adjustment. That is, when aligned on the probe such a
device must give the same reading as a device that does not have the
capability of being independently adjusted. With the fully assembled
probe (including probe shaft extensions, if any) secured in a horizontal
position, affix one yaw angle-measuring device to the probe sheath and
lock it into position on the reference scribe line specified in section
6.1.5.1. Position the second angle-measuring device using the procedure
in section 18.1.1.1 or 18.1.1.2.
18.1.1.1 Marking procedure. The procedures in this section should be
performed at each location on the fully assembled probe where the yaw
angle-measuring device will be mounted during the velocity traverse.
Place the second yaw angle-measuring device on the main probe sheath (or
extension) at the position where a yaw angle will be measured during the
velocity traverse. Adjust the position of the second angle-measuring
device until it indicates the same angle (1[deg])
as the reference device, and affix the second device to the probe sheath
(or extension). Record the angles indicated by the two angle-measuring
devices on a form similar to table 2G-2. In this position, the second
angle-measuring device is considered to be properly positioned for yaw
angle measurement. Make a mark, no wider than 1.6 mm (\1/16\ in.), on
the probe sheath (or extension), such that the yaw angle-measuring
device can be re-affixed at this same properly aligned position during
the velocity traverse.
18.1.1.2 Procedure for probe extensions with scribe lines. If,
during a velocity traverse the angle-measuring device will be affixed to
a probe extension having a scribe line as specified in section 6.1.5.2,
the following procedure may be used to align the extension's scribe line
with the reference scribe line instead of marking the extension as
described in section 18.1.1.1. Attach the probe extension to the main
probe. Align and lock the second angle-measuring device on the probe
extension's scribe line. Then, rotate the extension until both measuring
devices indicate the same angle (1[deg]). Lock the
extension at this rotational position. Record the angles indicated by
the two angle-measuring devices on a form similar to table 2G-2. An
angle-measuring device may be aligned at any position on this scribe
line during the velocity traverse, if the scribe line meets the
alignment specification in section 6.1.5.3.
18.1.1.3 Post-test rotational position check. If the fully assembled
probe includes one or more extensions, the following check should be
performed immediately after the completion of a velocity traverse. At
the discretion
[[Page 109]]
of the tester, additional checks may be conducted after completion of
testing at any sample port. Without altering the alignment of any of the
components of the probe assembly used in the velocity traverse, secure
the fully assembled probe in a horizontal position. Affix an angle-
measuring device at the reference scribe line specified in section
6.1.5.1. Use the other angle-measuring device to check the angle at each
location where the device was checked prior to testing. Record the
readings from the two angle-measuring devices.
18.1.2 Rotational position check with probe in stack. This section
applies only to probes that, due to physical constraints, cannot be
inserted into the test port as fully assembled with all necessary
extensions needed to reach the inner-most traverse point(s).
18.1.2.1 Perform the out-of-stack procedure in section 18.1.1 on the
main probe and any attached extensions that will be initially inserted
into the test port.
18.1.2.2 Use the following procedures to perform additional
rotational position check(s) with the probe in the stack, each time a
probe extension is added. Two angle-measuring devices are required. The
first of these is the device that was used to measure yaw angles at the
preceding traverse point, left in its properly aligned measurement
position. The second angle-measuring device is positioned on the added
probe extension. Use the applicable procedures in section 18.1.1.1 or
18.1.1.2 to align, adjust, lock, and mark (if necessary) the position of
the second angle-measuring device to within 1[deg]
of the first device. Record the readings of the two devices on a form
similar to Table 2G-2.
18.1.2.3 The procedure in section 18.1.2.2 should be performed at
the first port where measurements are taken. The procedure should be
repeated each time a probe extension is re-attached at a subsequent
port, unless the probe extensions are designed to be locked into a
mechanically fixed rotational position (e.g., through use of
interlocking grooves), which can be reproduced from port to port as
specified in section 8.3.5.2.
18.2 Annex B--Angle Measurement Protocol for Protractor Wheel and
Pointer Device. The following procedure shall be used when a protractor
wheel and pointer assembly, such as the one described in section 6.2.2
and illustrated in Figure 2G-5 is used to measure the yaw angle of flow.
With each move to a new traverse point, unlock, re-align, and re-lock
the probe, angle-pointer collar, and protractor wheel to each other. At
each such move, particular attention is required to ensure that the
scribe line on the angle pointer collar is either aligned with the
reference scribe line on the main probe sheath or is at the rotational
offset position established under section 8.3.1. The procedure consists
of the following steps:
18.2.1 Affix a protractor wheel to the entry port for the test probe
in the stack or duct.
18.2.2 Orient the protractor wheel so that the 0[deg] mark
corresponds to the longitudinal axis of the stack or duct. For stacks,
vertical ducts, or ports on the side of horizontal ducts, use a digital
inclinometer meeting the specifications in section 6.2.1 to locate the
0[deg] orientation. For ports on the top or bottom of horizontal ducts,
identify the longitudinal axis at each test port and permanently mark
the duct to indicate the 0[deg] orientation. Once the protractor wheel
is properly aligned, lock it into position on the test port.
18.2.3 Move the pointer assembly along the probe sheath to the
position needed to take measurements at the first traverse point. Align
the scribe line on the pointer collar with the reference scribe line or
at the rotational offset position established under section 8.3.1.
Maintaining this rotational alignment, lock the pointer device onto the
probe sheath. Insert the probe into the entry port to the depth needed
to take measurements at the first traverse point.
18.2.4 Perform the yaw angle determination as specified in sections
8.9.3 and 8.9.4 and record the angle as shown by the pointer on the
protractor wheel. Then, take velocity pressure and temperature
measurements in accordance with the procedure in section 8.9.5. Perform
the alignment check described in section 8.9.6.
18.2.5 After taking velocity pressure measurements at that traverse
point, unlock the probe from the collar and slide the probe through the
collar to the depth needed to reach the next traverse point.
18.2.6 Align the scribe line on the pointer collar with the
reference scribe line on the main probe or at the rotational offset
position established under section 8.3.1. Lock the collar onto the
probe.
18.2.7 Repeat the steps in sections 18.2.4 through 18.2.6 at the
remaining traverse points accessed from the current stack or duct entry
port.
18.2.8 After completing the measurement at the last traverse point
accessed from a port, verify that the orientation of the protractor
wheel on the test port has not changed over the course of the traverse
at that port. For stacks, vertical ducts, or ports on the side of
horizontal ducts, use a digital inclinometer meeting the specifications
in section 6.2.1 to check the rotational position of the 0[deg] mark on
the protractor wheel. For ports on the top or bottom of horizontal
ducts, observe the alignment of the angle wheel 0[deg] mark relative to
the permanent 0[deg] mark on the duct at that test port. If these
observed comparisons exceed 2[deg] of 0[deg], all
angle and pressure measurements taken at that port since the protractor
wheel was last locked into position on the port shall be repeated.
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18.2.9 Move to the next stack or duct entry port and repeat the
steps in sections 18.2.1 through 18.2.8.
18.3 Annex C--Guideline for Reference Scribe Line Placement. Use of
the following guideline is recommended to satisfy the requirements of
section 10.4 of this method. The rotational position of the reference
scribe line should be either 90[deg] or 180[deg] from the probe's impact
pressure port. For Type-S probes, place separate scribe lines, on
opposite sides of the probe sheath, if both the A and B sides of the
pitot tube are to be used for yaw angle measurements.
18.4 Annex D--Determination of Reference Scribe Line Rotational
Offset. The following procedures are recommended for determining the
magnitude and sign of a probe's reference scribe line rotational offset,
RSLO. Separate procedures are provided for two types of
angle-measuring devices: digital inclinometers and protractor wheel and
pointer assemblies.
18.4.1 Perform the following procedures on the main probe with all
devices that will be attached to the main probe in the field [such as
thermocouples, resistance temperature detectors (RTDs), or sampling
nozzles] that may affect the flow around the probe head. Probe shaft
extensions that do not affect flow around the probe head need not be
attached during calibration.
18.4.2 The procedures below assume that the wind tunnel duct used
for probe calibration is horizontal and that the flow in the calibration
wind tunnel is axial as determined by the axial flow verification check
described in section 10.1.2. Angle-measuring devices are assumed to
display angles in alternating 0[deg] to 90[deg] and 90[deg] to 0[deg]
intervals. If angle-measuring devices with other readout conventions are
used or if other calibration wind tunnel duct configurations are used,
make the appropriate calculational corrections. For Type-S probes,
calibrate the A-side and B-sides separately, using the appropriate
scribe line (see section 18.3, above), if both the A and B sides of the
pitot tube are to be used for yaw angle determinations.
18.4.2.1 Position the angle-measuring device in accordance with one
of the following procedures.
18.4.2.1.1 If using a digital inclinometer, affix the calibrated
digital inclinometer to the probe. If the digital inclinometer can be
independently adjusted after being locked into position on the probe
sheath (e.g., by means of a set screw), the independent adjustment must
be set so that the device performs exactly like a device without the
capability for independent adjustment. That is, when aligned on the
probe the device must give the same readings as a device that does not
have the capability of being independently adjusted. Either align it
directly on the reference scribe line or on a mark aligned with the
scribe line determined according to the procedures in section 18.1.1.1.
Maintaining this rotational alignment, lock the digital inclinometer
onto the probe sheath.
18.4.2.1.2 If using a protractor wheel and pointer device, orient
the protractor wheel on the test port so that the 0[deg] mark is aligned
with the longitudinal axis of the wind tunnel duct. Maintaining this
alignment, lock the wheel into place on the wind tunnel test port. Align
the scribe line on the pointer collar with the reference scribe line or
with a mark aligned with the reference scribe line, as determined under
section 18.1.1.1. Maintaining this rotational alignment, lock the
pointer device onto the probe sheath.
18.4.2.2 Zero the pressure-measuring device used for yaw nulling.
18.4.2.3 Insert the probe assembly into the wind tunnel through the
entry port, positioning the probe's impact port at the calibration
location. Check the responsiveness of the pressure-measuring device to
probe rotation, taking corrective action if the response is
unacceptable.
18.4.2.4 Ensure that the probe is in a horizontal position using a
carpenter's level.
18.4.2.5 Rotate the probe either clockwise or counterclockwise until
a yaw null [zero [Delta]P for a Type S probe or zero (P2-
P3) for a 3-D probe] is obtained. If using a Type S probe
with an attached thermocouple, the direction of the probe rotation shall
be such that the thermocouple is located downstream of the probe
pressure ports at the yaw-null position.
18.4.2.6 Read and record the value of [theta]null, the
angle indicated by the angle-measuring device at the yaw-null position.
Record the angle reading on a form similar to Table 2G-6. Do not
associate an algebraic sign with this reading.
18.4.2.7 Determine the magnitude and algebraic sign of the reference
scribe line rotational offset, RSLO. The magnitude of
RSLO will be equal to either [theta]null or
(90[deg]-[theta]null), depending on the type of probe being
calibrated and the type of angle-measuring device used. (See Table 2G-7
for a summary.) The algebraic sign of RSLO will either be
positive if the rotational position of the reference scribe line is
clockwise or negative if counterclockwise with respect to the probe's
yaw-null position. Figure 2G-10 illustrates how the magnitude and sign
of RSLO are determined.
18.4.2.8 Perform the steps in sections 18.3.2.3 through 18.3.2.7
twice at each of the two calibration velocities selected for the probe
under section 10.6. Record the values of RSLO in a form
similar to Table 2G-6.
18.4.2.9 The average of all RSLO values is the reference
scribe line rotational offset for the probe.
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Method 2H--Determination of Stack Gas Velocity Taking Into Account
Velocity Decay Near the Stack Wall
1.0 Scope and Application
1.1 This method is applicable in conjunction with Methods 2, 2F, and
2G (40 CFR Part 60, Appendix A) to account for velocity decay near the
wall in circular stacks and ducts.
1.2 This method is not applicable for testing stacks and ducts less
than 3.3 ft (1.0 m) in diameter.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 A wall effects adjustment factor is determined. It is used to
adjust the average stack gas velocity obtained under Method 2, 2F, or 2G
of this appendix to take into account velocity decay near the stack or
duct wall.
2.2 The method contains two possible procedures: a calculational
approach which derives an adjustment factor from velocity measurements
and a default procedure which assigns a generic adjustment factor based
on the construction of the stack or duct.
2.2.1 The calculational procedure derives a wall effects adjustment
factor from velocity measurements taken using Method 2, 2F, or 2G at 16
(or more) traverse points specified under Method 1 of this appendix and
a total of eight (or more) wall effects traverse points specified under
this method. The calculational procedure based on velocity measurements
is not applicable for horizontal circular ducts where build-up of
particulate matter or other material in the bottom of the duct is
present.
2.2.2 A default wall effects adjustment factor of 0.9900 for brick
and mortar stacks and 0.9950 for all other types of stacks and ducts may
be used without taking wall effects measurements in a stack or duct.
2.3 When the calculational procedure is conducted as part of a
relative accuracy test audit (RATA) or other multiple-run test
procedure, the wall effects adjustment factor derived from a single
traverse (i.e., single RATA run) may be applied to all runs of the same
RATA without repeating the wall effects measurements. Alternatively,
wall effects adjustment factors may be derived for several traverses and
an average wall effects adjustment factor applied to all runs of the
same RATA.
3.0 Definitions.
3.1 Complete wall effects traverse means a traverse in which
measurements are taken at drem (see section 3.3) and at 1-in.
intervals in each of the four Method 1 equal-area sectors closest to the
wall, beginning not farther than 4 in. (10.2 cm) from the wall and
extending either (1) across the entire width of the Method 1 equal-area
sector or (2) for stacks or ducts where this width exceeds 12 in. (30.5
cm) (i.e., stacks or ducts greater than or equal to 15.6 ft [4.8 m] in
diameter), to a distance of not less than 12 in. (30.5 cm) from the
wall. Note: Because this method specifies that measurements must be
taken at whole number multiples of 1 in. from a stack or duct wall, for
clarity numerical quantities in this method are expressed in English
units followed by metric units in parentheses. To enhance readability,
hyphenated terms such as ``1-in. intervals'' or ``1-in. incremented,''
are expressed in English units only.
3.2 dlast Depending on context, dlast means either (1) the distance
from the wall of the last 1-in. incremented wall effects traverse point
or (2) the traverse point located at that distance (see Figure 2H-2).
3.3 drem Depending on context, drem means either (1) the distance
from the wall of the centroid of the area between dlast and the interior
edge of the Method 1 equal-area sector closest to the wall or (2) the
traverse point located at that distance (see Figure 2H-2).
3.4 ``May,'' ``Must,'' ``Shall,'' ``Should,'' and the imperative
form of verbs.
3.4.1 ``May'' is used to indicate that a provision of this method is
optional.
3.4.2 ``Must,'' ``Shall,'' and the imperative form of verbs (such as
``record'' or ``enter'') are used to indicate that a provision of this
method is mandatory.
3.4.3 ``Should'' is used to indicate that a provision of this method
is not mandatory but is highly recommended as good practice.
3.5 Method 1 refers to 40 CFR part 60, appendix A, ``Method 1--
Sample and velocity traverses for stationary sources.''
3.6 Method 1 exterior equal-area sector and Method 1 equal-area
sector closest to the wall mean any one of the four equal-area sectors
that are closest to the wall for a circular stack or duct laid out in
accordance with section 2.3.1 of Method 1 (see Figure 2H-1).
3.7 Method 1 interior equal-area sector means any of the equal-area
sectors other than the Method 1 exterior equal-area sectors (as defined
in section 3.6) for a circular stack or duct laid out in accordance with
section 2.3.1 of Method 1 (see Figure 2H-1).
3.8 Method 1 traverse point and Method 1 equal-area traverse point
mean a traverse point located at the centroid of an equal-area sector of
a circular stack laid out in accordance with section 2.3.1 of Method 1.
3.9 Method 2 refers to 40 CFR part 60, appendix A, ``Method 2--
Determination of stack gas velocity and volumetric flow rate (Type S
pitot tube).''
3.10 Method 2F refers to 40 CFR part 60, appendix A, ``Method 2F--
Determination of stack gas velocity and volumetric flow rate with three-
dimensional probes.''
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3.11 Method 2G refers to 40 CFR part 60, appendix A, ``Method 2G--
Determination of stack gas velocity and volumetric flow rate with two-
dimensional probes.''
3.12 1-in. incremented wall effects traverse point means any of the
wall effects traverse points that are located at 1-in. intervals, i.e.,
traverse points d1 through dlast (see Figure 2H-2).
3.13 Partial wall effects traverse means a traverse in which
measurements are taken at fewer than the number of traverse points
required for a ``complete wall effects traverse'' (as defined in section
3.1), but are taken at a minimum of two traverse points in each Method 1
equal-area sector closest to the wall, as specified in section 8.2.2.
3.14 Relative accuracy test audit (RATA) is a field test procedure
performed in a stack or duct in which a series of concurrent
measurements of the same stack gas stream is taken by a reference method
and an installed monitoring system. A RATA usually consists of series of
9 to 12 sets of such concurrent measurements, each of which is referred
to as a RATA run. In a volumetric flow RATA, each reference method run
consists of a complete traverse of the stack or duct.
3.15 Wall effects-unadjusted average velocity means the average
stack gas velocity, not accounting for velocity decay near the wall, as
determined in accordance with Method 2, 2F, or 2G for a Method 1
traverse consisting of 16 or more points.
3.16 Wall effects-adjusted average velocity means the average stack
gas velocity, taking into account velocity decay near the wall, as
calculated from measurements at 16 or more Method 1 traverse points and
at the additional wall effects traverse points specified in this method.
3.17 Wall effects traverse point means a traverse point located in
accordance with sections 8.2.2 or 8.2.3 of this method.
4.0 Interferences [Reserved]
5.0 Safety
5.1 This method may involve hazardous materials, operations, and
equipment. This method does not purport to address all of the health and
safety considerations associated with its use. It is the responsibility
of the user of this method to establish appropriate health and safety
practices and to determine the applicability of occupational health and
safety regulatory requirements prior to performing this method.
6.0 Equipment and Supplies
6.1 The provisions pertaining to equipment and supplies in the
method that is used to take the traverse point measurements (i.e.,
Method 2, 2F, or 2G) are applicable under this method.
7.0 Reagents and Standards [Reserved]
8.0 Sample Collection and Analysis
8.1 Default Wall Effects Adjustment Factors. A default wall effects
adjustment factor of 0.9900 for brick and mortar stacks and 0.9950 for
all other types of stacks and ducts may be used without conducting the
following procedures.
8.2 Traverse Point Locations. Determine the location of the Method 1
traverse points in accordance with section 8.2.1 and the location of the
traverse points for either a partial wall effects traverse in accordance
with section 8.2.2 or a complete wall effects traverse in accordance
with section 8.2.3.
8.2.1 Method 1 equal-area traverse point locations. Determine the
location of the Method 1 equal-area traverse points for a traverse
consisting of 16 or more points using Table 1-2 (Location of Traverse
Points in Circular Stacks) of Method 1.
8.2.2 Partial wall effects traverse. For a partial wall effects
traverse, measurements must be taken at a minimum of the following two
wall effects traverse point locations in all four Method 1 equal-area
sectors closest to the wall: (1) 1 in. (2.5 cm) from the wall (except as
provided in section 8.2.2.1) and (2) drem, as determined
using Equation 2H-1 or 2H-2 (see section 8.2.2.2).
8.2.2.1 If the probe cannot be positioned at 1 in. (2.5 cm) from the
wall (e.g., because of insufficient room to withdraw the probe shaft) or
if velocity pressure cannot be detected at 1 in. (2.5 cm) from the wall
(for any reason other than build-up of particulate matter in the bottom
of a duct), take measurements at the 1-in. incremented wall effects
traverse point closest to the wall where the probe can be positioned and
velocity pressure can be detected.
8.2.2.2 Calculate the distance of drem from the wall to
within \1/4\ in. (6.4 mm) using Equation 2H-1 or
Equation 2H-2 (for a 16-point traverse).
[GRAPHIC] [TIFF OMITTED] TR14MY99.074
Where:
r = the stack or duct radius determined from direct measurement of the
stack or duct diameter in accordance with section 8.6 of
Method 2F or Method 2G, in. (cm);
p = the number of Method 1 equal-area traverse points on a diameter, p
=8 (e.g., for a 16-point traverse, p = 8); dlast
and drem are defined in sections 3.2 and 3.3 respectively, in.
(cm).
For a 16-point Method 1 traverse, Equation 2H-1 becomes:
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8.2.2.3 Measurements may be taken at any number of additional wall
effects traverse points, with the following provisions.
(a) dlast must not be closer to the center of the stack or duct than
the distance of the interior edge (boundary), db, of the Method 1 equal-
area sector closest to the wall (see Figure 2H-2 or 2H-3). That is,
Where:
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Table 2H-1 shows db as a function of the stack or duct radius, r, for
traverses ranging from 16 to 48 points (i.e., for values of p ranging
from 8 to 24).
(b) Each point must be located at a distance that is a whole number
(e.g., 1, 2, 3) multiple of 1 in. (2.5 cm).
(c) Points do not have to be located at consecutive 1-in. intervals.
That is, one or more 1-in. incremented points may be skipped. For
example, it would be acceptable for points to be located at 1 in. (2.5
cm), 3 in. (7.6 cm), 5 in. (12.7 cm), dlast, and drem; or at 1 in. (2.5
cm), 2 in. (5.1 cm), 4 in. (10.2 cm), 7 in. (17.8 cm), dlast, and drem.
Follow the instructions in section 8.7.1.2 of this method for recording
results for wall effects traverse points that are skipped. It should be
noted that the full extent of velocity decay may not be accounted for if
measurements are not taken at all 1-in. incremented points close to the
wall.
8.2.3 Complete wall effects traverse. For a complete wall effects
traverse, measurements must be taken at the following points in all four
Method 1 equal-area sectors closest to the wall.
(a) The 1-in. incremented wall effects traverse point closest to the
wall where the probe can be positioned and velocity can be detected, but
no farther than 4 in. (10.2 cm) from the wall.
(b) Every subsequent 1-in. incremented wall effects traverse point
out to the interior edge of the Method 1 equal-area sector or to 12 in.
(30.5 cm) from the wall, whichever comes first. Note: In stacks or ducts
with diameters greater than 15.6 ft (4.8 m) the interior edge of the
Method 1 equal-area sector is farther from the wall than 12 in. (30.5
cm).
(c) drem, as determined using Equation 2H-1 or 2H-2 (as
applicable). Note: For a complete traverse of a stack or duct with a
diameter less than 16.5 ft (5.0 m), the distance between drem
and dlast is less than or equal to \1/2\ in. (12.7 mm). As
discussed in section 8.2.4.2, when the distance between drem
and dlast is less than or equal to \1/2\ in. (12.7 mm), the
velocity measured at dlast may be used for drem.
Thus, it is not necessary to calculate the distance of drem
or to take measurements at drem when conducting a complete
traverse of a stack or duct with a diameter less than 16.5 ft (5.0 m).
8.2.4 Special considerations. The following special considerations
apply when the distance between traverse points is less than or equal to
\1/2\ in. (12.7 mm).
8.2.4.1 A wall effects traverse point and the Method 1 traverse
point. If the distance between a wall effects traverse point and the
Method 1 traverse point is less than or equal to \1/2\ in. (12.7 mm),
taking measurements at both points is allowed but not required or
recommended; if measurements are taken at only one point, take the
measurements at the point that is farther from the wall and use the
velocity obtained at that point as the value for both points (see
sections 8.2.3 and 9.2 for related requirements).
8.2.4.2 drem and dlast. If the distance
between drem and dlast is less than or equal to
\1/2\ in. (12.7 mm), taking measurements at drem is allowed
but not required or recommended; if measurements are not taken at
drem, the measured velocity value at dlast must be
used as the value for both dlast and drem.
8.3 Traverse Point Sampling Order and Probe Selection. Determine the
sampling order of the Method 1 and wall effects traverse points and
select the appropriate probe for the measurements, taking into account
the following considerations.
8.3.1 Traverse points on any radius may be sampled in either
direction (i.e., from the wall toward the center of the stack or duct,
or vice versa).
8.3.2 To reduce the likelihood of velocity variations during the
time of the traverse and the attendant potential impact on the wall
effects-adjusted and unadjusted average velocities, the following
provisions of this method shall be met.
8.3.2.1 Each complete set of Method 1 and wall effects traverse
points accessed from the same port shall be sampled without
interruption. Unless traverses are performed simultaneously in all ports
using separate probes at each port, this provision disallows first
sampling all Method 1 points at all ports and then sampling all the wall
effects points.
8.3.2.2 The entire integrated Method 1 and wall effects traverse
across all test ports shall be as short as practicable, consistent with
the measurement system response time
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(see section 8.4.1.1) and sampling (see section 8.4.1.2) provisions of
this method.
8.3.3 It is recommended but not required that in each Method 1
equal-area sector closest to the wall, the Method 1 equal-area traverse
point should be sampled in sequence between the adjacent wall effects
traverse points. For example, for the traverse point configuration shown
in Figure 2H-2, it is recommended that the Method 1 equal-area traverse
point be sampled between dlast and drem. In this
example, if the traverse is conducted from the wall toward the center of
the stack or duct, it is recommended that measurements be taken at
points in the following order: d1, d2,
dlast, the Method 1 traverse point, drem, and then
at the traverse points in the three Method 1 interior equal-area
sectors.
8.3.4 The same type of probe must be used to take measurements at
all Method 1 and wall effects traverse points. However, different copies
of the same type of probe may be used at different ports (e.g., Type S
probe 1 at port A, Type S probe 2 at port B) or at different traverse
points accessed from a particular port (e.g., Type S probe 1 for Method
1 interior traverse points accessed from port A, Type S probe 2 for wall
effects traverse points and the Method 1 exterior traverse point
accessed from port A). The identification number of the probe used to
obtain measurements at each traverse point must be recorded.
8.4 Measurements at Method 1 and Wall Effects Traverse Points.
Conduct measurements at Method 1 and wall effects traverse points in
accordance with Method 2, 2F, or 2G and in accordance with the
provisions of the following subsections (some of which are included in
Methods 2F and 2G but not in Method 2), which are particularly important
for wall effects testing.
8.4.1 Probe residence time at wall effects traverse points. Due to
the steep temperature and pressure gradients that can occur close to the
wall, it is very important for the probe residence time (i.e., the total
time spent at a traverse point) to be long enough to ensure collection
of representative temperature and pressure measurements. The provisions
of Methods 2F and 2G in the following subsections shall be observed.
8.4.1.1 System response time. Determine the response time of each
probe measurement system by inserting and positioning the ``cold'' probe
(at ambient temperature and pressure) at any Method 1 traverse point.
Read and record the probe differential pressure, temperature, and
elapsed time at 15-second intervals until stable readings for both
pressure and temperature are achieved. The response time is the longer
of these two elapsed times. Record the response time.
8.4.1.2 Sampling. At the start of testing in each port (i.e., after
a probe has been inserted into the stack gas stream), allow at least the
response time to elapse before beginning to take measurements at the
first traverse point accessed from that port. Provided that the probe is
not removed from the stack gas stream, measurements may be taken at
subsequent traverse points accessed from the same test port without
waiting again for the response time to elapse.
8.4.2 Temperature measurement for wall effects traverse points.
Either (1) take temperature measurements at each wall effects traverse
point in accordance with the applicable provisions of Method 2, 2F, or
2G; or (2) use the temperature measurement at the Method 1 traverse
point closest to the wall as the temperature measurement for all the
wall effects traverse points in the corresponding equal-area sector.
8.4.3 Non-detectable velocity pressure at wall effects traverse
points. If the probe cannot be positioned at a wall effects traverse
point or if no velocity pressure can be detected at a wall effects
point, measurements shall be taken at the first subsequent wall effects
traverse point farther from the wall where velocity can be detected.
Follow the instructions in section 8.7.1.2 of this method for recording
results for wall effects traverse points where velocity pressure cannot
be detected. It should be noted that the full extent of velocity decay
may not be accounted for if measurements are not taken at the 1-in.
incremented wall effects traverse points closest to the wall.
8.5 Data Recording. For each wall effects and Method 1 traverse
point where measurements are taken, record all pressure, temperature,
and attendant measurements prescribed in section 3 of Method 2 or
section 8.0 of Method 2F or 2G, as applicable.
8.6 Point Velocity Calculation. For each wall effects and Method 1
traverse point, calculate the point velocity value (vi) in accordance
with sections 12.1 and 12.2 of Method 2F for tests using Method 2F and
in accordance with sections 12.1 and 12.2 of Method 2G for tests using
Method 2 and Method 2G. (Note that the term (vi) in this method
corresponds to the term (va(i)) in Methods 2F and 2G.) When the
equations in the indicated sections of Method 2G are used in deriving
point velocity values for Method 2 tests, set the value of the yaw
angles appearing in the equations to 0[deg].
8.7 Tabulating Calculated Point Velocity Values for Wall Effects
Traverse Points. Enter the following values in a hardcopy or electronic
form similar to Form 2H-1 (for 16-point Method 1 traverses) or Form 2H-2
(for Method 1 traverses consisting of more than 16 points). A separate
form must be completed for each of the four Method 1 equal-area sectors
that are closest to the wall.
(a) Port ID (e.g., A, B, C, or D)
(b) Probe type
(c) Probe ID
[[Page 130]]
(d) Stack or duct diameter in ft (m) (determined in accordance with
section 8.6 of Method 2F or Method 2G)
(e) Stack or duct radius in in. (cm)
(f) Distance from the wall of wall effects traverse points at 1-in.
intervals, in ascending order starting with 1 in. (2.5 cm) (column A of
Form 2H-1 or 2H-2)
(g) Point velocity values (vd) for 1-in. incremented traverse points
(see section 8.7.1), including dlast (see section 8.7.2)
(h) Point velocity value (vdrem) at drem (see section 8.7.3).
8.7.1 Point velocity values at wall effects traverse points other
than dlast. For every 1-in. incremented wall effects traverse point
other than dlast, enter in column B of Form 2H-1 or 2H-2 either the
velocity measured at the point (see section 8.7.1.1) or the velocity
measured at the first subsequent traverse point farther from the wall
(see section 8.7.1.2). A velocity value must be entered in column B of
Form 2H-1 or 2H-2 for every 1-in. incremented traverse point from d1
(representing the wall effects traverse point 1 in. [2.5 cm] from the
wall) to dlast.
8.7.1.1 For wall effects traverse points where the probe can be
positioned and velocity pressure can be detected, enter the value
obtained in accordance with section 8.6.
8.7.1.2 For wall effects traverse points that were skipped [see
section 8.2.2.3(c)] and for points where the probe cannot be positioned
or where no velocity pressure can be detected, enter the value obtained
at the first subsequent traverse point farther from the wall where
velocity pressure was detected and measured and follow the entered value
with a ``flag,'' such as the notation ``NM,'' to indicate that ``no
measurements'' were actually taken at this point.
8.7.2 Point velocity value at dlast. For dlast, enter in column B of
Form 2H-1 or 2H-2 the measured value obtained in accordance with section
8.6.
8.7.3 Point velocity value (vdrem) at drem. Enter the point velocity
value obtained at drem in column G of row 4a in Form 2H-1 or 2H-2. If
the distance between drem and dlast is less than or equal to \1/2\ in.
(12.7 mm), the measured velocity value at dlast may be used as the value
at drem (see section 8.2.4.2).
9.0 Quality Control.
9.1 Particulate Matter Build-up in Horizontal Ducts. Wall effects
testing of horizontal circular ducts should be conducted only if build-
up of particulate matter or other material in the bottom of the duct is
not present.
9.2 Verifying Traverse Point Distances. In taking measurements at
wall effects traverse points, it is very important for the probe impact
pressure port to be positioned as close as practicable to the traverse
point locations in the gas stream. For this reason, before beginning
wall effects testing, it is important to calculate and record the
traverse point positions that will be marked on each probe for each
port, taking into account the distance that each port nipple (or probe
mounting flange for automated probes) extends out of the stack and any
extension of the port nipple (or mounting flange) into the gas stream.
To ensure that traverse point positions are properly identified, the
following procedures should be performed on each probe used.
9.2.1 Manual probes. Mark the probe insertion distance of the wall
effects and Method 1 traverse points on the probe sheath so that when a
mark is aligned with the outside face of the stack port, the probe
impact port is located at the calculated distance of the traverse point
from the stack inside wall. The use of different colored marks is
recommended for designating the wall effects and Method 1 traverse
points. Before the first use of each probe, check to ensure that the
distance of each mark from the center of the probe impact pressure port
agrees with the previously calculated traverse point positions to within
\1/4\ in. (6.4 mm).
9.2.2 Automated probe systems. For automated probe systems that
mechanically position the probe head at prescribed traverse point
positions, activate the system with the probe assemblies removed from
the test ports and sequentially extend the probes to the programmed
location of each wall effects traverse point and the Method 1 traverse
points. Measure the distance between the center of the probe impact
pressure port and the inside of the probe assembly mounting flange for
each traverse point. The measured distances must agree with the
previously calculated traverse point positions to within \1/4\ in. (6.4 mm).
9.3 Probe Installation. Properly sealing the port area is
particularly important in taking measurements at wall effects traverse
points. For testing involving manual probes, the area between the probe
sheath and the port should be sealed with a tightly fitting flexible
seal made of an appropriate material such as heavy cloth so that leakage
is minimized. For automated probe systems, the probe assembly mounting
flange area should be checked to verify that there is no leakage.
9.4 Velocity Stability. This method should be performed only when
the average gas velocity in the stack or duct is relatively constant
over the duration of the test. If the average gas velocity changes
significantly during the course of a wall effects test, the test results
should be discarded.
10.0 Calibration
10.1 The calibration coefficient(s) or curves obtained under Method
2, 2F, or 2G and used to perform the Method 1 traverse are applicable
under this method.
[[Page 131]]
11.0 Analytical Procedure
11.1 Sample collection and analysis are concurrent for this method
(see section 8).
12.0 Data Analysis and Calculations
12.1 The following calculations shall be performed to obtain a wall
effects adjustment factor (WAF) from (1) the wall effects-unadjusted
average velocity (T4avg), (2) the replacement velocity (vej) for each of
the four Method 1 sectors closest to the wall, and (3) the average stack
gas velocity that accounts for velocity decay near the wall (vavg).
12.2 Nomenclature. The following terms are listed in the order in
which they appear in Equations 2H-5 through 2H-21.
vavg = the average stack gas velocity, unadjusted for wall effects,
actual ft/sec (m/sec);
vii = stack gas point velocity value at Method 1 interior equal-area
sectors, actual ft/sec (m/sec);
vej = stack gas point velocity value, unadjusted for wall effects, at
Method 1 exterior equal-area sectors, actual ft/sec (m/sec);
i = index of Method 1 interior equal-area traverse points;
j = index of Method 1 exterior equal-area traverse points;
n = total number of traverse points in the Method 1 traverse;
vdecd = the wall effects decay velocity for a sub-sector located between
the traverse points at distances d-1 (in metric units, d-2.5)
and d from the wall, actual ft/sec (m/sec);
vd = the measured stack gas velocity at distance d from the wall, actual
ft/sec (m/sec); Note: v0 = 0;
d = the distance of a 1-in. incremented wall effects traverse point from
the wall, for traverse points d1 through dlast, in. (cm);
Ad = the cross-sectional area of a sub-sector located between the
traverse points at distances d-1 (in metric units, d-2.5) and
d from the wall, in.\2\ (cm\2\) ( e.g., sub-sector
A2 shown in Figures 2H-3 and 2H-4);
r = the stack or duct radius, in. (cm);
Qd = the stack gas volumetric flow rate for a sub-sector located between
the traverse points at distances d-1 (in metric units, d-2.5)
and d from the wall, actual ft-in.\2\/sec (m-cm\2\/sec);
Qd1[rarr]dlast = the total stack gas volumetric flow rate for all sub-
sectors located between the wall and dlast, actual ft-in.\2\/
sec (m-cm\2\/sec);
dlast = the distance from the wall of the last 1-in. incremented wall
effects traverse point, in. (cm);
Adrem = the cross-sectional area of the sub-sector located between dlast
and the interior edge of the Method 1 equal-area sector
closest to the wall, in.\2\ (cm\2\) (see Figure 2H-4);
p = the number of Method 1 traverse points per diameter, p=8
(e.g., for a 16-point traverse, p = 8);
drem = the distance from the wall of the centroid of the area between
dlast and the interior edge of the Method 1 equal-area sector
closest to the wall, in. (cm);
Qdrem = the total stack gas volumetric flow rate for the sub-sector
located between dlast and the interior edge of the Method 1
equal-area sector closest to the wall, actual ft-in.\2\/sec
(m-cm\2\/sec);
vdrem = the measured stack gas velocity at distance drem from the wall,
actual ft/sec (m/sec);
QT = the total stack gas volumetric flow rate for the Method 1 equal-
area sector closest to the wall, actual ft-in.\2\/sec (m-
cm\2\/sec);
vej = the replacement stack gas velocity for the Method 1 equal-area
sector closest to the wall, i.e., the stack gas point velocity
value, adjusted for wall effects, for the j\th\ Method 1
equal-area sector closest to the wall, actual ft/sec (m/sec);
vavg = the average stack gas velocity that accounts for velocity decay
near the wall, actual ft/sec (m/sec);
WAF = the wall effects adjustment factor derived from vavg and vavg for
a single traverse, dimensionless;
vfinal = the final wall effects-adjusted average stack gas velocity that
replaces the unadjusted average stack gas velocity obtained
using Method 2, 2F, or 2G for a field test consisting of a
single traverse, actual ft/sec (m/sec);
WAF = the wall effects adjustment factor that is applied to the average
velocity, unadjusted for wall effects, in order to obtain the
final wall effects-adjusted stack gas velocity, vfinal or,
vfinal(k), dimensionless;
vfinal(k) = the final wall effects-adjusted average stack gas velocity
that replaces the unadjusted average stack gas velocity
obtained using Method 2, 2F, or 2G on run k of a RATA or other
multiple-run field test procedure, actual ft/sec (m/sec);
vavg(k) = the average stack gas velocity, obtained on run k of a RATA or
other multiple-run procedure, unadjusted for velocity decay
near the wall, actual ft/sec (m/sec);
k=index of runs in a RATA or other multiple-run procedure.
12.3 Calculate the average stack gas velocity that does not account
for velocity decay near the wall (vavg) using Equation 2H-5.
[[Page 132]]
[GRAPHIC] [TIFF OMITTED] TR14MY99.077
(Note that vavg in Equation 2H-5 is the same as v(a)avg in Equations 2F-
9 and 2G-8 in Methods 2F and 2G, respectively.)
For a 16-point traverse, Equation 2H-5 may be written as follows:
[GRAPHIC] [TIFF OMITTED] TR14MY99.078
12.4 Calculate the replacement velocity, vej, for each of the four
Method 1 equal-area sectors closest to the wall using the procedures
described in sections 12.4.1 through 12.4.8. Forms 2H-1 and 2H-2 provide
sample tables that may be used in either hardcopy or spreadsheet format
to perform the calculations described in sections 12.4.1 through 12.4.8.
Forms 2H-3 and 2H-4 provide examples of Form 2H-1 filled in for partial
and complete wall effects traverses.
12.4.1 Calculate the average velocity (designated the ``decay
velocity,'' vdecd) for each sub-sector located between the
wall and dlast (see Figure 2H-3) using Equation 2H-7.
[GRAPHIC] [TIFF OMITTED] TR14MY99.079
For each line in column A of Form 2H-1 or 2H-2 that contains a value of
d, enter the corresponding calculated value of vdecd in
column C.
12.4.2 Calculate the cross-sectional area between the wall and the
first 1-in. incremented wall effects traverse point and between
successive 1-in. incremented wall effects traverse points, from the wall
to dlast (see Figure 2H-3), using Equation 2H-8.
[GRAPHIC] [TIFF OMITTED] TR14MY99.080
For each line in column A of Form 2H-1 or 2H-2 that contains a value of
d, enter the value of the expression \1/4\ [pi](r-d + 1)\2\ in column D,
the value of the expression \1/4\ [pi](r-d)\2\ in column E, and the
value of Ad in column F. Note that Equation 2H-8 is designed
for use only with English units (in.). If metric units (cm) are used,
the first term, \1/4\ [pi](r-d + 1)\2\, must be changed to \1/4\ [pi](r-
d + 2.5)\2\. This change must also be made in column D of Form 2H-1 or
2H-2.
12.4.3 Calculate the volumetric flow through each cross-sectional
area derived in section 12.4.2 by multiplying the values of vdecd,
derived according to section 12.4.1, by the cross-sectional areas
derived in section 12.4.2 using Equation 2H-9.
[GRAPHIC] [TIFF OMITTED] TR14MY99.081
For each line in column A of Form 2H-1 or 2H-2 that contains a value of
d, enter the corresponding calculated value of Qd in column G.
12.4.4 Calculate the total volumetric flow through all sub-sectors
located between the wall and dlast, using Equation 2H-10.
[GRAPHIC] [TIFF OMITTED] TN09JY99.003
Enter the calculated value of Qd1[rarr]cdlast in line 3 of column G of
Form 2H-1 or 2H-2.
12.4.5 Calculate the cross-sectional area of the sub-sector located
between dlast and the interior edge of the Method 1 equal-area sector
(e.g., sub-sector Adrem shown in Figures 2H-3 and 2H-4) using Equation
2H-11.
[GRAPHIC] [TIFF OMITTED] TR14MY99.083
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For a 16-point traverse (eight points per diameter), Equation 2H-11 may
be written as follows:
[GRAPHIC] [TIFF OMITTED] TR14MY99.084
Enter the calculated value of Adrem in line 4b of column G of
Form 2H-1 or 2H-2.
12.4.6 Calculate the volumetric flow for the sub-sector located
between dlast and the interior edge of the Method 1 equal-
area sector, using Equation 2H-13.
[GRAPHIC] [TIFF OMITTED] TR14MY99.085
In Equation 2H-13, vdrem is either (1) the measured velocity
value at drem or (2) the measured velocity at
dlast, if the distance between drem and
dlast is less than or equal to \1/2\ in. (12.7 mm) and no
velocity measurement is taken at drem (see section 8.2.4.2).
Enter the calculated value of Qdrem in line 4c of column G of
Form 2H-1 or 2H-2.
12.4.7 Calculate the total volumetric flow for the Method 1 equal-
area sector closest to the wall, using Equation 2H-14.
[GRAPHIC] [TIFF OMITTED] TR14MY99.086
Enter the calculated value of QT in line 5a of column G of
Form 2H-1 or 2H-2.
12.4.8 Calculate the wall effects-adjusted replacement velocity
value for the Method 1 equal-area sector closest to the wall, using
Equation 2H-15.
[GRAPHIC] [TIFF OMITTED] TR14MY99.087
For a 16-point traverse (eight points per diameter), Equation 2H-15 may
be written as follows:
[GRAPHIC] [TIFF OMITTED] TR14MY99.088
Enter the calculated value of vej in line 5B of column G of Form 2H-1 or
2H-2.
12.5 Calculate the wall effects-adjusted average velocity, vavg, by
replacing the four values of vej shown in Equation 2H-5 with
the four wall effects-adjusted replacement velocity
values,vej, calculated according to section 12.4.8, using
Equation 2H-17.
[GRAPHIC] [TIFF OMITTED] TR14MY99.089
For a 16-point traverse, Equation 2H-17 may be written as follows:
[GRAPHIC] [TIFF OMITTED] TR14MY99.090
12.6 Calculate the wall effects adjustment factor, WAF, using
Equation 2H-19.
[GRAPHIC] [TIFF OMITTED] TR14MY99.091
12.6.1 Partial wall effects traverse. If a partial wall effects
traverse (see section 8.2.2) is conducted, the value obtained from
Equation 2H-19 is acceptable and may be reported as the wall effects
adjustment factor provided that the value is greater than or equal to
0.9800. If the value is less than 0.9800, it shall not be used and a
wall effects adjustment factor of 0.9800 may be used instead.
12.6.2 Complete wall effects traverse. If a complete wall effects
traverse (see section 8.2.3) is conducted, the value obtained from
Equation 2H-19 is acceptable and may be reported as the wall effects
adjustment factor provided that the value is greater than or equal to
0.9700. If the value is less than 0.9700, it shall not be used and a
wall effects adjustment factor of 0.9700 may be used instead. If the
wall effects adjustment factor for a particular stack or duct is less
than 0.9700, the tester may (1) repeat the wall effects test, taking
measurements at more Method 1 traverse points and (2) recalculate the
wall effects adjustment factor from these measurements, in an attempt to
obtain a wall effects adjustment factor that meets the 0.9700
specification and completely characterizes the wall effects.
12.7 Applying a Wall Effects Adjustment Factor. A default wall
effects adjustment factor, as specified in section 8.1, or a calculated
wall effects adjustment factor meeting the requirements of section
12.6.1 or 12.6.2
[[Page 134]]
may be used to adjust the average stack gas velocity obtained using
Methods 2, 2F, or 2G to take into account velocity decay near the wall
of circular stacks or ducts. Default wall effects adjustment factors
specified in section 8.1 and calculated wall effects adjustment factors
that meet the requirements of section 12.6.1 and 12.6.2 are summarized
in Table 2H-2.
12.7.1 Single-run tests. Calculate the final wall effects-adjusted
average stack gas velocity for field tests consisting of a single
traverse using Equation 2H-20.
[GRAPHIC] [TIFF OMITTED] TR14MY99.092
The wall effects adjustment factor, WAF, shown in Equation 2H-20, may be
(1) a default wall effects adjustment factor, as specified in section
8.1, or (2) a calculated adjustment factor that meets the specifications
in sections 12.6.1 or 12.6.2. If a calculated adjustment factor is used
in Equation 2H-20, the factor must have been obtained during the same
traverse in which vavg was obtained.
12.7.2 RATA or other multiple run test procedure. Calculate the
final wall effects-adjusted average stack gas velocity for any run k of
a RATA or other multiple-run procedure using Equation 2H-21.
[GRAPHIC] [TIFF OMITTED] TR14MY99.093
The wall effects adjustment factor, WAF, shown in Equation 2H-21 may be
(1) a default wall effects adjustment factor, as specified in section
8.1; (2) a calculated adjustment factor (meeting the specifications in
sections 12.6.1 or 12.6.2) obtained from any single run of the RATA that
includes run k; or (3) the arithmetic average of more than one WAF (each
meeting the specifications in sections 12.6.1 or 12.6.2) obtained
through wall effects testing conducted during several runs of the RATA
that includes run k. If wall effects adjustment factors (meeting the
specifications in sections 12.6.1 or 12.6.2) are determined for more
than one RATA run, the arithmetic average of all of the resulting
calculated wall effects adjustment factors must be used as the value of
WAF and applied to all runs of that RATA. If a calculated, not a
default, wall effects adjustment factor is used in Equation 2H-21, the
average velocity unadjusted for wall effects, vavg(k) must be
obtained from runs in which the number of Method 1 traverse points
sampled does not exceed the number of Method 1 traverse points in the
runs used to derive the wall effects adjustment factor, WAF, shown in
Equation 2H-21.
12.8 Calculating Volumetric Flow Using Final Wall Effects-Adjusted
Average Velocity Value. To obtain a stack gas flow rate that accounts
for velocity decay near the wall of circular stacks or ducts, replace
vs in Equation 2-10 in Method 2, or va(avg) in
Equations 2F-10 and 2F-11 in Method 2F, or va(avg) in
Equations 2G-9 and 2G-10 in Method 2G with one of the following.
12.8.1 For single-run test procedures, use the final wall effects-
adjusted average stack gas velocity, vfinal, calculated according to
Equation 2H-20.
12.8.2 For RATA and other multiple run test procedures, use the
final wall effects-adjusted average stack gas velocity, vfinal(k),
calculated according to Equation 2H-21.
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Reporting
16.1 Field Test Reports. Field test reports shall be submitted to
the Agency according to the applicable regulatory requirements. When
Method 2H is performed in conjunction with Method 2, 2F, or 2G to derive
a wall effects adjustment factor, a single consolidated Method 2H/2F (or
2H/2G) field test report should be prepared. At a minimum, the
consolidated field test report should contain (1) all of the general
information, and data for Method 1 points, specified in section 16.0 of
Method 2F (when Method 2H is used in conjunction with Method 2F) or
section 16.0 of Method 2G (when Method 2H is used in conjunction with
Method 2 or 2G) and (2) the additional general information, and data for
Method 1 points and wall effects points, specified in this section (some
of which are included in section 16.0 of Methods 2F and 2G and are
repeated in this section to ensure complete reporting for wall effects
testing).
16.1.1 Description of the source and site. The field test report
should include the descriptive information specified in section 16.1.1
of Method 2F (when using Method 2F) or 2G (when using either Method 2 or
2G). It should also include a description of the stack or duct's
construction material along with the diagram showing the dimensions of
the stack or duct at the test port elevation prescribed in Methods 2F
and 2G. The diagram should indicate the location of all wall effects
traverse points where measurements were taken as well as the Method 1
traverse points. The diagram should provide a unique identification
number for each wall effects and Method 1 traverse point, its distance
from the wall, and its location relative to the probe entry ports.
16.1.2 Field test forms. The field test report should include a copy
of Form 2H-1, 2H-2, or an equivalent for each Method 1 exterior equal-
area sector.
16.1.3 Field test data. The field test report should include the
following data for the Method 1 and wall effects traverse.
16.1.3.1 Data for each traverse point. The field test report should
include the values
[[Page 135]]
specified in section 16.1.3.2 of Method 2F (when using Method 2F) or 2G
(when using either Method 2 or 2G) for each Method 1 and wall effects
traverse point. The provisions of section 8.4.2 of Method 2H apply to
the temperature measurements reported for wall effects traverse points.
For each wall effects and Method 1 traverse point, the following values
should also be included in the field test report.
(a) Traverse point identification number for each Method 1 and wall
effects traverse point.
(b) Probe type.
(c) Probe identification number.
(d) Probe velocity calibration coefficient (i.e., Cp when Method 2
or 2G is used; F2 when Method 2F is used).
For each Method 1 traverse point in an exterior equal-area sector,
the following additional value should be included.
(e) Calculated replacement velocity, vej, accounting for wall
effects.
16.1.3.2 Data for each run. The values specified in section 16.1.3.3
of Method 2F (when using Method 2F) or 2G (when using either Method 2 or
2G) should be included in the field test report once for each run. The
provisions of section 12.8 of Method 2H apply for calculating the
reported gas volumetric flow rate. In addition, the following Method 2H
run values should also be included in the field test report.
(a) Average velocity for run, accounting for wall effects, vavg.
(b) Wall effects adjustment factor derived from a test run, WAF.
16.1.3.3 Data for a complete set of runs. The values specified in
section 16.1.3.4 of Method 2F (when using Method 2F) or 2G (when using
either Method 2 or 2G) should be included in the field test report once
for each complete set of runs. In addition, the field test report should
include the wall effects adjustment factor, WAF, that is applied in
accordance with section 12.7.1 or 12.7.2 to obtain the final wall
effects-adjusted average stack gas velocity vfinal or vfinal(k).
16.1.4 Quality assurance and control. Quality assurance and control
procedures, specifically tailored to wall effects testing, should be
described.
16.2 Reporting a Default Wall Effects Adjustment Factor. When a
default wall effects adjustment factor is used in accordance with
section 8.1 of this method, its value and a description of the stack or
duct's construction material should be reported in lieu of submitting a
test report.
17.0 References.
(1) 40 CFR Part 60, Appendix A, Method 1--Sample and velocity
traverses for stationary sources.
(2) 40 CFR Part 60, Appendix A, Method 2--Determination of stack gas
velocity and volumetric flow rate (Type S pitot tube).
(3) 40 CFR Part 60, Appendix A, Method 2F--Determination of stack
gas velocity and volumetric flow rate with three-dimensional probes.
(4) 40 CFR Part 60, Appendix A, Method 2G--Determination of stack
gas velocity and volumetric flow rate with two-dimensional probes.
(5) 40 CFR Part 60, Appendix A, Method 3--Gas analysis for carbon
dioxide, oxygen, excess air, and dry molecular weight.
(6) 40 CFR Part 60, Appendix A, Method 3A--Determination of oxygen
and carbon dioxide concentrations in emissions from stationary sources
(instrumental analyzer procedure).
(7) 40 CFR Part 60, Appendix A, Method 4--Determination of moisture
content in stack gases.
(8) Emission Measurement Center (EMC) Approved Alternative Method
(ALT-011) ``Alternative Method 2 Thermocouple Calibration Procedure.''
(9) The Cadmus Group, Inc., 1998, ``EPA Flow Reference Method
Testing and Analysis: Data Report, Texas Utilities, DeCordova Steam
Electric Station, Volume I: Test Description and Appendix A (Data
Distribution Package),'' EPA/430-R-98-015a.
(10) The Cadmus Group, Inc., 1998, ``EPA Flow Reference Method
Testing and Analysis: Data Report, Texas Utilities, Lake Hubbard Steam
Electric Station, Volume I: Test Description and Appendix A (Data
Distribution Package),'' EPA/430-R-98-017a.
(11) The Cadmus Group, Inc., 1998, ``EPA Flow Reference Method
Testing and Analysis: Data Report, Pennsylvania Electric Co., G.P.U.
Genco Homer City Station: Unit 1, Volume I: Test Description and
Appendix A (Data Distribution Package),'' EPA/430-R-98-018a.
(12) The Cadmus Group, Inc., May 1999, ``EPA Flow Reference Method
Testing and Analysis: Findings Report,'' EPA/430-R-99-009.
(13) The Cadmus Group, Inc., 1997, ``EPA Flow Reference Method
Testing and Analysis: Wind Tunnel Experimental Results,'' EPA/430-R-97-
013.
(14) National Institute of Standards and Technology, 1998, ``Report
of Special Test of Air Speed Instrumentation, Four Prandtl Probes, Four
S-Type Probes, Four French Probes, Four Modified Kiel Probes,'' Prepared
for the U.S. Environmental Protection Agency under IAG No. DW13938432-
01-0.
(15) National Institute of Standards and Technology, 1998, ``Report
of Special Test of Air Speed Instrumentation, Five Autoprobes,''
Prepared for the U.S. Environmental Protection Agency under IAG No.
DW13938432-01-0.
[[Page 136]]
(16) National Institute of Standards and Technology, 1998, ``Report
of Special Test of Air Speed Instrumentation, Eight Spherical Probes,''
Prepared for the U.S. Environmental Protection Agency under IAG No.
DW13938432-01-0.
(17) National Institute of Standards and Technology, 1998, ``Report
of Special Test of Air Speed Instrumentation, Four DAT Probes,''
Prepared for the U.S. Environmental Protection Agency under IAG No.
DW13938432-01-0.
(18) Massachusetts Institute of Technology (MIT), 1998,
``Calibration of Eight Wind Speed Probes Over a Reynolds Number Range of
46,000 to 725,000 per Foot, Text and Summary Plots,'' Plus Appendices,
WBWT-TR-1317, Prepared for The Cadmus Group, Inc., under EPA Contract
68-W6-0050, Work Assignment 0007AA-3.
(19) Fossil Energy Research Corporation, Final Report, ``Velocity
Probe Tests in Non-axial Flow Fields,'' November 1998, Prepared for the
U.S. Environmental Protection Agency.
(20) Fossil Energy Research Corporation, ``Additional Swirl Tunnel
Tests: E-DAT and T-DAT Probes,'' February 24, 1999, Technical Memorandum
Prepared for U.S. Environmental Protection Agency, P.O. No. 7W-1193-
NALX.
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Method 3--Gas Analysis for the Determination of Dry Molecular Weight
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling) essential to its
performance. Some material is incorporated by reference from other
methods in this part. Therefore, to obtain reliable results, persons
using this method should also have a thorough knowledge of Method 1.
1.0 Scope and Application
1.1 Analytes.
[[Page 145]]
------------------------------------------------------------------------
Analytes CAS No. Sensitivity
------------------------------------------------------------------------
Oxygen (O2)....................... 7782-44-7 2,000 ppmv.
Nitrogen (N2)..................... 7727-37-9 N/A.
Carbon dioxide (CO2).............. 124-38-9 2,000 ppmv.
Carbon monoxide (CO).............. 630-08-0 N/A.
------------------------------------------------------------------------
1.2 Applicability. This method is applicable for the determination
of CO2 and O2 concentrations and dry molecular
weight of a sample from an effluent gas stream of a fossil-fuel
combustion process or other process.
1.3 Other methods, as well as modifications to the procedure
described herein, are also applicable for all of the above
determinations. Examples of specific methods and modifications include:
(1) A multi-point grab sampling method using an Orsat analyzer to
analyze the individual grab sample obtained at each point; (2) a method
for measuring either CO2 or O2 and using
stoichiometric calculations to determine dry molecular weight; and (3)
assigning a value of 30.0 for dry molecular weight, in lieu of actual
measurements, for processes burning natural gas, coal, or oil. These
methods and modifications may be used, but are subject to the approval
of the Administrator. The method may also be applicable to other
processes where it has been determined that compounds other than
CO2, O2, carbon monoxide (CO), and nitrogen
(N2) are not present in concentrations sufficient to affect
the results.
1.4 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 A gas sample is extracted from a stack by one of the following
methods: (1) single-point, grab sampling; (2) single-point, integrated
sampling; or (3) multi-point, integrated sampling. The gas sample is
analyzed for percent CO2 and percent O2. For dry
molecular weight determination, either an Orsat or a Fyrite analyzer may
be used for the analysis.
3.0 Definitions [Reserved]
4.0 Interferences
4.1 Several compounds can interfere, to varying degrees, with the
results of Orsat or Fyrite analyses. Compounds that interfere with
CO2 concentration measurement include acid gases (e.g.,
sulfur dioxide, hydrogen chloride); compounds that interfere with
O2 concentration measurement include unsaturated hydrocarbons
(e.g., acetone, acetylene), nitrous oxide, and ammonia. Ammonia reacts
chemically with the O2 absorbing solution, and when present
in the effluent gas stream must be removed before analysis.
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and determine the applicability of regulatory limitations
prior to performing this test method.
5.2 Corrosive Reagents.
5.2.1 A typical Orsat analyzer requires four reagents: a gas-
confining solution, CO2 absorbent, O2 absorbent,
and CO absorbent. These reagents may contain potassium hydroxide, sodium
hydroxide, cuprous chloride, cuprous sulfate, alkaline pyrogallic acid,
and/or chromous chloride. Follow manufacturer's operating instructions
and observe all warning labels for reagent use.
5.2.2 A typical Fyrite analyzer contains zinc chloride, hydrochloric
acid, and either potassium hydroxide or chromous chloride. Follow
manufacturer's operating instructions and observe all warning labels for
reagent use.
6.0 Equipment and Supplies
Note: As an alternative to the sampling apparatus and systems
described herein, other sampling systems (e.g., liquid displacement) may
be used, provided such systems are capable of obtaining a representative
sample and maintaining a constant sampling rate, and are, otherwise,
capable of yielding acceptable results. Use of such systems is subject
to the approval of the Administrator.
6.1 Grab Sampling (See Figure 3-1).
6.1.1 Probe. Stainless steel or borosilicate glass tubing equipped
with an in-stack or out-of-stack filter to remove particulate matter (a
plug of glass wool is satisfactory for this purpose). Any other
materials, resistant to temperature at sampling conditions and inert to
all components of the gas stream, may be used for the probe. Examples of
such materials may include aluminum, copper, quartz glass, and Teflon.
6.1.2 Pump. A one-way squeeze bulb, or equivalent, to transport the
gas sample to the analyzer.
6.2 Integrated Sampling (Figure 3-2).
6.2.1 Probe. Same as in section 6.1.1.
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6.2.2 Condenser. An air-cooled or water-cooled condenser, or other
condenser no greater than 250 ml that will not remove O2,
CO2, CO, and N2, to remove excess moisture which
would interfere with the operation of the pump and flowmeter.
6.2.3 Valve. A needle valve, to adjust sample gas flow rate.
6.2.4 Pump. A leak-free, diaphragm-type pump, or equivalent, to
transport sample gas to the flexible bag. Install a small surge tank
between the pump and rate meter to eliminate the pulsation effect of the
diaphragm pump on the rate meter.
6.2.5 Rate Meter. A rotameter, or equivalent, capable of measuring
flow rate to 2 percent of the selected flow rate.
A flow rate range of 500 to 1000 ml/min is suggested.
6.2.6 Flexible Bag. Any leak-free plastic (e.g., Tedlar, Mylar,
Teflon) or plastic-coated aluminum (e.g., aluminized Mylar) bag, or
equivalent, having a capacity consistent with the selected flow rate and
duration of the test run. A capacity in the range of 55 to 90 liters
(1.9 to 3.2 ft\3\) is suggested. To leak-check the bag, connect it to a
water manometer, and pressurize the bag to 5 to 10 cm H2O (2
to 4 in. H2O). Allow to stand for 10 minutes. Any
displacement in the water manometer indicates a leak. An alternative
leak-check method is to pressurize the bag to 5 to 10 cm (2 to 4 in.)
H2O and allow to stand overnight. A deflated bag indicates a
leak.
6.2.7 Pressure Gauge. A water-filled U-tube manometer, or
equivalent, of about 30 cm (12 in.), for the flexible bag leak-check.
6.2.8 Vacuum Gauge. A mercury manometer, or equivalent, of at least
760 mm (30 in.) Hg, for the sampling train leak-check.
6.3 Analysis. An Orsat or Fyrite type combustion gas analyzer.
7.0 Reagents and Standards
7.1 Reagents. As specified by the Orsat or Fyrite-type combustion
analyzer manufacturer.
7.2 Standards. Two standard gas mixtures, traceable to National
Institute of Standards and Technology (NIST) standards, to be used in
auditing the accuracy of the analyzer and the analyzer operator
technique:
7.2.1. Gas cylinder containing 2 to 4 percent O2 and 14
to 18 percent CO2.
7.2.2. Gas cylinder containing 2 to 4 percent CO2 and
about 15 percent O2.
8.0 Sample Collection, Preservation, Storage, and Transport
8.1 Single Point, Grab Sampling Procedure.
8.1.1 The sampling point in the duct shall either be at the centroid
of the cross section or at a point no closer to the walls than 1.0 m
(3.3 ft), unless otherwise specified by the Administrator.
8.1.2 Set up the equipment as shown in Figure 3-1, making sure all
connections ahead of the analyzer are tight. If an Orsat analyzer is
used, it is recommended that the analyzer be leak-checked by following
the procedure in section 11.5; however, the leak-check is optional.
8.1.3 Place the probe in the stack, with the tip of the probe
positioned at the sampling point. Purge the sampling line long enough to
allow at least five exchanges. Draw a sample into the analyzer, and
immediately analyze it for percent CO2 and percent
O2 according to section 11.2.
8.2 Single-Point, Integrated Sampling Procedure.
8.2.1 The sampling point in the duct shall be located as specified
in section 8.1.1.
8.2.2 Leak-check (optional) the flexible bag as in section 6.2.6.
Set up the equipment as shown in Figure 3-2. Just before sampling, leak-
check (optional) the train by placing a vacuum gauge at the condenser
inlet, pulling a vacuum of at least 250 mm Hg (10 in. Hg), plugging the
outlet at the quick disconnect, and then turning off the pump. The
vacuum should remain stable for at least 0.5 minute. Evacuate the
flexible bag. Connect the probe, and place it in the stack, with the tip
of the probe positioned at the sampling point. Purge the sampling line.
Next, connect the bag, and make sure that all connections are tight.
8.2.3 Sample Collection. Sample at a constant rate (10 percent). The sampling run should be simultaneous
with, and for the same total length of time as, the pollutant emission
rate determination. Collection of at least 28 liters (1.0 ft\3\) of
sample gas is recommended; however, smaller volumes may be collected, if
desired.
8.2.4 Obtain one integrated flue gas sample during each pollutant
emission rate determination. Within 8 hours after the sample is taken,
analyze it for percent CO2 and percent O2 using
either an Orsat analyzer or a Fyrite type combustion gas analyzer
according to section 11.3.
Note: When using an Orsat analyzer, periodic Fyrite readings may be
taken to verify/confirm the results obtained from the Orsat.
8.3 Multi-Point, Integrated Sampling Procedure.
8.3.1 Unless otherwise specified in an applicable regulation, or by
the Administrator, a minimum of eight traverse points shall be used for
circular stacks having diameters less than 0.61 m (24 in.), a minimum of
nine shall be used for rectangular stacks having equivalent diameters
less than 0.61 m (24 in.), and a minimum of 12 traverse points shall be
used for all other cases. The traverse points shall be located according
to Method 1.
8.3.2 Follow the procedures outlined in sections 8.2.2 through
8.2.4, except for the following: Traverse all sampling points, and
sample at each point for an equal length of
[[Page 147]]
time. Record sampling data as shown in Figure 3-3.
9.0 Quality Control
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
8.2........................... Use of Fyrite to Ensures the accurate
confirm Orsat measurement of CO2
results. and O2.
10.1.......................... Periodic audit of Ensures that the
analyzer and analyzer is
operator operating properly
technique. and that the
operator performs
the sampling
procedure correctly
and accurately.
11.3.......................... Replicable Minimizes
analyses of experimental error.
integrated
samples.
------------------------------------------------------------------------
10.0 Calibration and Standardization
10.1 Analyzer. The analyzer and analyzer operator's technique should
be audited periodically as follows: take a sample from a manifold
containing a known mixture of CO2 and O2, and
analyze according to the procedure in section 11.3. Repeat this
procedure until the measured concentration of three consecutive samples
agrees with the stated value 0.5 percent. If
necessary, take corrective action, as specified in the analyzer users
manual.
10.2 Rotameter. The rotameter need not be calibrated, but should be
cleaned and maintained according to the manufacturer's instruction.
11.0 Analytical Procedure
11.1 Maintenance. The Orsat or Fyrite-type analyzer should be
maintained and operated according to the manufacturers specifications.
11.2 Grab Sample Analysis. Use either an Orsat analyzer or a Fyrite-
type combustion gas analyzer to measure O2 and CO2
concentration for dry molecular weight determination, using procedures
as specified in the analyzer user's manual. If an Orsat analyzer is
used, it is recommended that the Orsat leak-check, described in section
11.5, be performed before this determination; however, the check is
optional. Calculate the dry molecular weight as indicated in section
12.0. Repeat the sampling, analysis, and calculation procedures until
the dry molecular weights of any three grab samples differ from their
mean by no more than 0.3 g/g-mole (0.3 lb/lb-mole). Average these three
molecular weights, and report the results to the nearest 0.1 g/g-mole
(0.1 lb/lb-mole).
11.3 Integrated Sample Analysis. Use either an Orsat analyzer or a
Fyrite-type combustion gas analyzer to measure O2 and
CO2 concentration for dry molecular weight determination,
using procedures as specified in the analyzer user's manual. If an Orsat
analyzer is used, it is recommended that the Orsat leak-check, described
in section 11.5, be performed before this determination; however, the
check is optional. Calculate the dry molecular weight as indicated in
section 12.0. Repeat the analysis and calculation procedures until the
individual dry molecular weights for any three analyses differ from
their mean by no more than 0.3 g/g-mole (0.3 lb/lb-mole). Average these
three molecular weights, and report the results to the nearest 0.1 g/g-
mole (0.1 lb/lb-mole).
11.4 Standardization. A periodic check of the reagents and of
operator technique should be conducted at least once every three series
of test runs as outlined in section 10.1.
11.5 Leak-Check Procedure for Orsat Analyzer. Moving an Orsat
analyzer frequently causes it to leak. Therefore, an Orsat analyzer
should be thoroughly leak-checked on site before the flue gas sample is
introduced into it. The procedure for leak-checking an Orsat analyzer is
as follows:
11.5.1 Bring the liquid level in each pipette up to the reference
mark on the capillary tubing, and then close the pipette stopcock.
11.5.2 Raise the leveling bulb sufficiently to bring the confining
liquid meniscus onto the graduated portion of the burette, and then
close the manifold stopcock.
11.5.3 Record the meniscus position.
11.5.4 Observe the meniscus in the burette and the liquid level in
the pipette for movement over the next 4 minutes.
11.5.5 For the Orsat analyzer to pass the leak-check, two conditions
must be met:
11.5.5.1 The liquid level in each pipette must not fall below the
bottom of the capillary tubing during this 4-minute interval.
11.5.5.2 The meniscus in the burette must not change by more than
0.2 ml during this 4-minute interval.
11.5.6 If the analyzer fails the leak-check procedure, check all
rubber connections and stopcocks to determine whether they might be the
cause of the leak. Disassemble, clean, and regrease any leaking
stopcocks. Replace leaking rubber connections. After the analyzer is
reassembled, repeat the leak-check procedure.
12.0 Calculations and Data Analysis
12.1 Nomenclature.
Md = Dry molecular weight, g/g-mole (lb/lb-mole).
%CO2 = Percent CO2 by volume, dry basis.
%O2 = Percent O2 by volume, dry basis.
%CO = Percent CO by volume, dry basis.
%N2 = Percent N2 by volume, dry basis.
[[Page 148]]
0.280 = Molecular weight of N2 or CO, divided by 100.
0.320 = Molecular weight of O2 divided by 100.
0.440 = Molecular weight of CO2 divided by 100.
12.2 Nitrogen, Carbon Monoxide Concentration. Determine the
percentage of the gas that is N2 and CO by subtracting the
sum of the percent CO2 and percent O2 from 100
percent.
12.3 Dry Molecular Weight. Use Equation 3-1 to calculate the dry
molecular weight of the stack gas.
[GRAPHIC] [TIFF OMITTED] TR17OC00.090
Note: The above Equation 3-1 does not consider the effect on
calculated dry molecular weight of argon in the effluent gas. The
concentration of argon, with a molecular weight of 39.9, in ambient air
is about 0.9 percent. A negative error of approximately 0.4 percent is
introduced. The tester may choose to include argon in the analysis using
procedures subject to approval of the Administrator.
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
1. Altshuller, A.P. Storage of Gases and Vapors in Plastic Bags.
International Journal of Air and Water Pollution. 6:75-81. 1963.
2. Conner, William D. and J.S. Nader. Air Sampling with Plastic
Bags. Journal of the American Industrial Hygiene Association. 25:291-
297. 1964.
3. Burrell Manual for Gas Analysts, Seventh edition. Burrell
Corporation, 2223 Fifth Avenue, Pittsburgh, PA. 15219. 1951.
4. Mitchell, W.J. and M.R. Midgett. Field Reliability of the Orsat
Analyzer. Journal of Air Pollution Control Association. 26:491-495. May
1976.
5. Shigehara, R.T., R.M. Neulicht, and W.S. Smith. Validating Orsat
Analysis Data from Fossil Fuel-Fired Units. Stack Sampling News.
4(2):21-26. August 1976.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
[GRAPHIC] [TIFF OMITTED] TR17OC00.091
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[GRAPHIC] [TIFF OMITTED] TR17OC00.092
----------------------------------------------------------------------------------------------------------------
Time Traverse point Q (liter/min) % Deviation \a\
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Average
----------------------------------------------------------------------------------------------------------------
\a\ % Dev.=[(Q-Qavg)/Qavg] x 100 (Must be <=10%)
Figure 3-3. Sampling Rate Data
Method 3A--Determination of Oxygen and Carbon Dioxide Concentrations in
Emissions From Stationary Sources (Instrumental Analyzer Procedure)
1.0 Scope and Application
What is Method 3A?
Method 3A is a procedure for measuring oxygen (O2) and
carbon dioxide (CO2) in stationary source emissions using a
continuous instrumental analyzer. Quality assurance and quality control
requirements are included to assure that you, the tester, collect data
of known quality. You must document your adherence to these specific
requirements for equipment, supplies, sample collection and analysis,
calculations, and data analysis.
This method does not completely describe all equipment, supplies,
and sampling and
[[Page 150]]
analytical procedures you will need but refers to other methods for some
of the details. Therefore, to obtain reliable results, you should also
have a thorough knowledge of these additional test methods which are
found in appendix A to this part:
(a) Method 1--Sample and Velocity Traverses for Stationary Sources.
(b) Method 3--Gas Analysis for the Determination of Molecular
Weight.
(c) Method 4--Determination of Moisture Content in Stack Gases.
(d) Method 7E--Determination of Nitrogen Oxides Emissions from
Stationary Sources (Instrumental Analyzer Procedure).
1.1 Analytes. What does this method determine? This method measures
the concentration of oxygen and carbon dioxide.
------------------------------------------------------------------------
Analyte CAS No. Sensitivity
------------------------------------------------------------------------
Oxygen (O2).................... 7782-44-7 Typically <2% of
Calibration Span.
Carbon dioxide (CO2)........... 124-38-9 Typically <2% of
Calibration Span.
------------------------------------------------------------------------
1.2 Applicability. When is this method required? The use of Method
3A may be required by specific New Source Performance Standards, Clean
Air Marketing rules, State Implementation Plans and permits, where
measurements of O2 and CO2 concentrations in
stationary source emissions must be made, either to determine compliance
with an applicable emission standard or to conduct performance testing
of a continuous emission monitoring system (CEMS). Other regulations may
also require the use of Method 3A.
1.3 Data Quality Objectives. How good must my collected data be?
Refer to section 1.3 of Method 7E.
2.0 Summary of Method
In this method, you continuously or intermittently sample the
effluent gas and convey the sample to an analyzer that measures the
concentration of O2 or CO2. You must meet the
performance requirements of this method to validate your data.
3.0 Definitions
Refer to section 3.0 of Method 7E for the applicable definitions.
4.0 Interferences [Reserved]
5.0 Safety
Refer to section 5.0 of Method 7E.
6.0 Equipment and Supplies
Figure 7E-1 in Method 7E is a schematic diagram of an acceptable
measurement system.
6.1 What do I need for the measurement system? The components of the
measurement system are described (as applicable) in sections 6.1 and 6.2
of Method 7E, except that the analyzer described in section 6.2 of this
method must be used instead of the analyzer described in Method 7E. You
must follow the noted specifications in section 6.1 of Method 7E except
that the requirements to use stainless steel, Teflon, or non-reactive
glass filters do not apply. Also, a heated sample line is not required
to transport dry gases or for systems that measure the O2 or
CO2 concentration on a dry basis, provided that the system is
not also being used to concurrently measure SO2 and/or
NOX.
6.2 What analyzer must I use? You must use an analyzer that
continuously measures O2 or CO2 in the gas stream
and meets the specifications in section 13.0.
7.0 Reagents and Standards
7.1 Calibration Gas. What calibration gases do I need? Refer to
Section 7.1 of Method 7E for the calibration gas requirements. Example
calibration gas mixtures are listed below. Pre-cleaned or scrubbed air
may be used for the O2 high-calibration gas provided it does
not contain other gases that interfere with the O2
measurement.
(a) CO2 in Nitrogen (N2).
(b) CO2/SO2 gas mixture in N2.
(c) O2/SO2 gas mixture in N2.
(d) O2/CO2/SO2 gas mixture in
N2.
(e) CO2/NOX gas mixture in N2.
(f) CO2/SO2/NOX gas mixture in
N2.
The tests for analyzer calibration error and system bias require
high-, mid-, and low-level gases.
7.2 Interference Check. What reagents do I need for the interference
check? Potential interferences may vary among available analyzers. Table
7E-3 of Method 7E lists a number of gases that should be considered in
conducting the interference test.
8.0 Sample Collection, Preservation, Storage, and Transport
8.1 Sampling Site and Sampling Points. You must follow the
procedures of section 8.1 of Method 7E to determine the appropriate
sampling points, unless you are using Method 3A only to determine the
stack gas molecular weight and for no other purpose. In that case, you
may use single-point integrated sampling as described in section 8.2.1
of Method 3. If the stratification test provisions in section 8.1.2 of
Method 7E are used to reduce the number of required sampling points, the
alternative acceptance criterion for 3-
[[Page 151]]
point sampling will be 0.5 percent CO2
or O2, and the alternative acceptance criterion for single-
point sampling will be 0.3 percent CO2
or O2. In that case, you may use single-point integrated
sampling as described in section 8.2.1 of Method 3.
8.2 Initial Measurement System Performance Tests. You must follow
the procedures in section 8.2 of Method 7E. If a dilution-type
measurement system is used, the special considerations in section 8.3 of
Method 7E apply.
8.3 Interference Check. The O2 or CO2 analyzer
must be documented to show that interference effects to not exceed 2.5
percent of the calibration span. The interference test in section 8.2.7
of Method 7E is a procedure that may be used to show this. The effects
of all potential interferences at the concentrations encountered during
testing must be addressed and documented. This testing and documentation
may be done by the instrument manufacturer.
8.4 Sample Collection. You must follow the procedures in section 8.4
of Method 7E.
8.5 Post-Run System Bias Check and Drift Assessment. You must follow
the procedures in section 8.5 of Method 7E.
9.0 Quality Control
Follow quality control procedures in section 9.0 of Method 7E.
10.0 Calibration and Standardization
Follow the procedures for calibration and standardization in section
10.0 of Method 7E.
11.0 Analytical Procedures
Because sample collection and analysis are performed together (see
section 8), additional discussion of the analytical procedure is not
necessary.
12.0 Calculations and Data Analysis
You must follow the applicable procedures for calculations and data
analysis in section 12.0 of Method 7E, substituting percent
O2 and percent CO2 for ppmv of NOX as
appropriate.
13.0 Method Performance
The specifications for the applicable performance checks are the
same as in section 13.0 of Method 7E except for the alternative
specifications for system bias, drift, and calibration error. In these
alternative specifications, replace the term ``0.5 ppmv'' with the term
``0.5 percent O2'' or ``0.5 percent CO2'' (as
applicable).
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Alternative Procedures [Reserved]
17.0 References
1. ``EPA Traceability Protocol for Assay and Certification of
Gaseous Calibration Standards'' September 1997 as amended, EPA-600/R-97/
121.
18.0 Tables, Diagrams, Flowcharts, and Validation Data
Refer to section 18.0 of Method 7E.
Method 3B--Gas Analysis for the Determination of Emission Rate
Correction Factor or Excess Air
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling) essential to its
performance. Some material is incorporated by reference from other
methods in this part. Therefore, to obtain reliable results, persons
using this method should have a thorough knowledge of at least the
following additional test methods: Method 1 and 3.
1.0 Scope and Application
1.1 Analytes.
------------------------------------------------------------------------
Analyte CAS No. Sensitivity
------------------------------------------------------------------------
Oxygen (O2)....................... 7782-44-7 2,000 ppmv.
Carbon Dioxide (CO2).............. 124-38-9 2,000 ppmv.
Carbon Monoxide (CO).............. 630-08-0 N/A.
------------------------------------------------------------------------
1.2 Applicability. This method is applicable for the determination
of O2, CO2, and CO concentrations in the effluent
from fossil-fuel combustion processes for use in excess air or emission
rate correction factor calculations. Where compounds other than
CO2, O2, CO, and nitrogen (N2) are
present in concentrations sufficient to affect the results, the
calculation procedures presented in this method must be modified,
subject to the approval of the Administrator.
1.3 Other methods, as well as modifications to the procedure
described herein, are also applicable for all of the above
determinations. Examples of specific methods and modifications include:
(1) A multi-point sampling method using an Orsat analyzer to analyze
individual grab samples obtained at each point, and (2) a method using
CO2 or O2 and stoichiometric calculations to
determine excess air. These methods and modifications may be used, but
are subject to the approval of the Administrator.
[[Page 152]]
1.4 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 A gas sample is extracted from a stack by one of the following
methods: (1) Single-point, grab sampling; (2) single-point, integrated
sampling; or (3) multi-point, integrated sampling. The gas sample is
analyzed for percent CO2, percent O2, and, if
necessary, percent CO using an Orsat combustion gas analyzer.
3.0 Definitions [Reserved]
4.0 Interferences
4.1 Several compounds can interfere, to varying degrees, with the
results of Orsat analyses. Compounds that interfere with CO2
concentration measurement include acid gases (e.g., sulfur dioxide,
hydrogen chloride); compounds that interfere with O2
concentration measurement include unsaturated hydrocarbons (e.g.,
acetone, acetylene), nitrous oxide, and ammonia. Ammonia reacts
chemically with the O2 absorbing solution, and when present
in the effluent gas stream must be removed before analysis.
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and determine the applicability of regulatory limitations
prior to performing this test method.
5.2 Corrosive Reagents. A typical Orsat analyzer requires four
reagents: a gas-confining solution, CO2 absorbent,
O2 absorbent, and CO absorbent. These reagents may contain
potassium hydroxide, sodium hydroxide, cuprous chloride, cuprous
sulfate, alkaline pyrogallic acid, and/or chromous chloride. Follow
manufacturer's operating instructions and observe all warning labels for
reagent use.
6.0 Equipment and Supplies
Note: As an alternative to the sampling apparatus and systems
described herein, other sampling systems (e.g., liquid displacement) may
be used, provided such systems are capable of obtaining a representative
sample and maintaining a constant sampling rate, and are, otherwise,
capable of yielding acceptable results. Use of such systems is subject
to the approval of the Administrator.
6.1 Grab Sampling and Integrated Sampling. Same as in sections 6.1
and 6.2, respectively for Method 3.
6.2 Analysis. An Orsat analyzer only. For low CO2 (less
than 4.0 percent) or high O2 (greater than 15.0 percent)
concentrations, the measuring burette of the Orsat must have at least
0.1 percent subdivisions. For Orsat maintenance and operation
procedures, follow the instructions recommended by the manufacturer,
unless otherwise specified herein.
7.0 Reagents and Standards
7.1 Reagents. Same as in Method 3, section 7.1.
7.2 Standards. Same as in Method 3, section 7.2.
8.0 Sample Collection, Preservation, Storage, and Transport
Note: Each of the three procedures below shall be used only when
specified in an applicable subpart of the standards. The use of these
procedures for other purposes must have specific prior approval of the
Administrator. A Fyrite-type combustion gas analyzer is not acceptable
for excess air or emission rate correction factor determinations, unless
approved by the Administrator. If both percent CO2 and
percent O2 are measured, the analytical results of any of the
three procedures given below may also be used for calculating the dry
molecular weight (see Method 3).
8.1 Single-Point, Grab Sampling and Analytical Procedure.
8.1.1 The sampling point in the duct shall either be at the centroid
of the cross section or at a point no closer to the walls than 1.0 m
(3.3 ft), unless otherwise specified by the Administrator.
8.1.2 Set up the equipment as shown in Figure 3-1 of Method 3,
making sure all connections ahead of the analyzer are tight. Leak-check
the Orsat analyzer according to the procedure described in section 11.5
of Method 3. This leak-check is mandatory.
8.1.3 Place the probe in the stack, with the tip of the probe
positioned at the sampling point; purge the sampling line long enough to
allow at least five exchanges. Draw a sample into the analyzer. For
emission rate correction factor determinations, immediately analyze the
sample for percent CO2 or percent O2, as outlined
in section 11.2. For excess air determination, immediately analyze the
sample for percent CO2, O2, and CO, as outlined in
section 11.2, and calculate excess air as outlined in section 12.2.
8.1.4 After the analysis is completed, leak-check (mandatory) the
Orsat analyzer once again, as described in section 11.5 of Method 3. For
the results of the analysis to be valid, the Orsat analyzer must pass
this leak-test before and after the analysis.
8.2 Single-Point, Integrated Sampling and Analytical Procedure.
[[Page 153]]
8.2.1 The sampling point in the duct shall be located as specified
in section 8.1.1.
8.2.2 Leak-check (mandatory) the flexible bag as in section 6.2.6 of
Method 3. Set up the equipment as shown in Figure 3-2 of Method 3. Just
before sampling, leak-check (mandatory) the train by placing a vacuum
gauge at the condenser inlet, pulling a vacuum of at least 250 mm Hg (10
in. Hg), plugging the outlet at the quick disconnect, and then turning
off the pump. The vacuum should remain stable for at least 0.5 minute.
Evacuate the flexible bag. Connect the probe, and place it in the stack,
with the tip of the probe positioned at the sampling point; purge the
sampling line. Next, connect the bag, and make sure that all connections
are tight.
8.2.3 Sample at a constant rate, or as specified by the
Administrator. The sampling run must be simultaneous with, and for the
same total length of time as, the pollutant emission rate determination.
Collect at least 28 liters (1.0 ft\3\) of sample gas. Smaller volumes
may be collected, subject to approval of the Administrator.
8.2.4 Obtain one integrated flue gas sample during each pollutant
emission rate determination. For emission rate correction factor
determination, analyze the sample within 4 hours after it is taken for
percent CO2 or percent O2 (as outlined in section
11.2).
8.3 Multi-Point, Integrated Sampling and Analytical Procedure.
8.3.1 Unless otherwise specified in an applicable regulation, or by
the Administrator, a minimum of eight traverse points shall be used for
circular stacks having diameters less than 0.61 m (24 in.), a minimum of
nine shall be used for rectangular stacks having equivalent diameters
less than 0.61 m (24 in.), and a minimum of 12 traverse points shall be
used for all other cases. The traverse points shall be located according
to Method 1.
8.3.2 Follow the procedures outlined in sections 8.2.2 through
8.2.4, except for the following: Traverse all sampling points, and
sample at each point for an equal length of time. Record sampling data
as shown in Figure 3-3 of Method 3.
9.0 Quality Control
9.1 Data Validation Using Fuel Factor. Although in most instances,
only CO2 or O2 measurement is required, it is
recommended that both CO2 and O2 be measured to
provide a check on the quality of the data. The data validation
procedure of section 12.3 is suggested.
Note: Since this method for validating the CO2 and
O2 analyses is based on combustion of organic and fossil
fuels and dilution of the gas stream with air, this method does not
apply to sources that (1) remove CO2 or O2 through
processes other than combustion, (2) add O2 (e.g., oxygen
enrichment) and N2 in proportions different from that of air,
(3) add CO2 (e.g., cement or lime kilns), or (4) have no fuel
factor, FO, values obtainable (e.g., extremely variable waste
mixtures). This method validates the measured proportions of
CO2 and O2 for fuel type, but the method does not
detect sample dilution resulting from leaks during or after sample
collection. The method is applicable for samples collected downstream of
most lime or limestone flue-gas desulfurization units as the
CO2 added or removed from the gas stream is not significant
in relation to the total CO2 concentration. The
CO2 concentrations from other types of scrubbers using only
water or basic slurry can be significantly affected and would render the
fuel factor check minimally useful.
10.0 Calibration and Standardization
10.1 Analyzer. The analyzer and analyzer operator technique should
be audited periodically as follows: take a sample from a manifold
containing a known mixture of CO2 and O2, and
analyze according to the procedure in section 11.3. Repeat this
procedure until the measured concentration of three consecutive samples
agrees with the stated value 0.5 percent. If
necessary, take corrective action, as specified in the analyzer users
manual.
10.2 Rotameter. The rotameter need not be calibrated, but should be
cleaned and maintained according to the manufacturer's instruction.
11.0 Analytical Procedure
11.1 Maintenance. The Orsat analyzer should be maintained according
to the manufacturers specifications.
11.2 Grab Sample Analysis. To ensure complete absorption of the
CO2, O2, or if applicable, CO, make repeated
passes through each absorbing solution until two consecutive readings
are the same. Several passes (three or four) should be made between
readings. (If constant readings cannot be obtained after three
consecutive readings, replace the absorbing solution.) Although in most
cases, only CO2 or O2 concentration is required,
it is recommended that both CO2 and O2 be
measured, and that the procedure in section 12.3 be used to validate the
analytical data.
Note: Since this single-point, grab sampling and analytical
procedure is normally conducted in conjunction with a single-point, grab
sampling and analytical procedure for a pollutant, only one analysis is
ordinarily conducted. Therefore, great care must be taken to obtain a
valid sample and analysis.
11.3 Integrated Sample Analysis. The Orsat analyzer must be leak-
checked (see section 11.5 of Method 3) before the analysis. If excess
air is desired, proceed as follows: (1) within 4 hours after the sample
is taken, analyze it (as in sections 11.3.1 through
[[Page 154]]
11.3.3) for percent CO2, O2, and CO; (2) determine
the percentage of the gas that is N2 by subtracting the sum
of the percent CO2, percent O2, and percent CO
from 100 percent; and (3) calculate percent excess air, as outlined in
section 12.2.
11.3.1 To ensure complete absorption of the CO2,
O2, or if applicable, CO, follow the procedure described in
section 11.2.
Note: Although in most instances only CO2 or
O2 is required, it is recommended that both CO2
and O2 be measured, and that the procedures in section 12.3
be used to validate the analytical data.
11.3.2 Repeat the analysis until the following criteria are met:
11.3.2.1 For percent CO2, repeat the analytical procedure
until the results of any three analyses differ by no more than (a) 0.3
percent by volume when CO2 is greater than 4.0 percent or (b)
0.2 percent by volume when CO2 is less than or equal to 4.0
percent. Average three acceptable values of percent CO2, and
report the results to the nearest 0.2 percent.
11.3.2.2 For percent O2, repeat the analytical procedure
until the results of any three analyses differ by no more than (a) 0.3
percent by volume when O2 is less than 15.0 percent or (b)
0.2 percent by volume when O2 is greater than or equal to
15.0 percent. Average the three acceptable values of percent
O2, and report the results to the nearest 0.1 percent.
11.3.2.3 For percent CO, repeat the analytical procedure until the
results of any three analyses differ by no more than 0.3 percent.
Average the three acceptable values of percent CO, and report the
results to the nearest 0.1 percent.
11.3.3 After the analysis is completed, leak-check (mandatory) the
Orsat analyzer once again, as described in section 11.5 of Method 3. For
the results of the analysis to be valid, the Orsat analyzer must pass
this leak-test before and after the analysis.
11.4 Standardization. A periodic check of the reagents and of
operator technique should be conducted at least once every three series
of test runs as indicated in section 10.1.
12.0 Calculations and Data Analysis
12.1 Nomenclature. Same as section 12.1 of Method 3 with the
addition of the following:
%EA = Percent excess air.
0.264 = Ratio of O2 to N2 in air, v/v.
12.2 Percent Excess Air. Determine the percentage of the gas that is
N2 by subtracting the sum of the percent CO2,
percent CO, and percent O2 from 100 percent. Calculate the
percent excess air (if applicable) by substituting the appropriate
values of percent O2, CO, and N2 into Equation 3B-
1.
[GRAPHIC] [TIFF OMITTED] TR17OC00.093
Note: The equation above assumes that ambient air is used as the
source of O2 and that the fuel does not contain appreciable
amounts of N2 (as do coke oven or blast furnace gases). For
those cases when appreciable amounts of N2 are present (coal,
oil, and natural gas do not contain appreciable amounts of
N2) or when oxygen enrichment is used, alternative methods,
subject to approval of the Administrator, are required.
12.3 Data Validation When Both CO2 and O2 Are
Measured.
12.3.1 Fuel Factor, Fo. Calculate the fuel factor (if
applicable) using Equation 3B-2:
[GRAPHIC] [TIFF OMITTED] TR17OC00.094
Where:
%O2 = Percent O2 by volume, dry basis.
%CO2 = Percent CO2 by volume, dry basis.
20.9 = Percent O2 by volume in ambient air.
If CO is present in quantities measurable by this method, adjust the
O2 and CO2 values using Equations 3B-3 and 3B-4
before performing the calculation for Fo:
[GRAPHIC] [TIFF OMITTED] TR17OC00.095
[GRAPHIC] [TIFF OMITTED] TR17OC00.096
Where:
%CO = Percent CO by volume, dry basis.
12.3.2 Compare the calculated Fo factor with the expected
Fo values. Table 3B-1 in section 17.0 may be used in
establishing acceptable ranges for the expected Fo if the
fuel being burned is known. When fuels are burned in combinations,
calculate the combined fuel Fd and Fc factors (as
defined in Method 19, section 12.2) according to the procedure in Method
19, sections 12.2 and 12.3. Then calculate the Fo factor
according to Equation 3B-5.
[GRAPHIC] [TIFF OMITTED] TR17OC00.097
[[Page 155]]
12.3.3 Calculated Fo values, beyond the acceptable ranges
shown in this table, should be investigated before accepting the test
results. For example, the strength of the solutions in the gas analyzer
and the analyzing technique should be checked by sampling and analyzing
a known concentration, such as air; the fuel factor should be reviewed
and verified. An acceptability range of 12 percent
is appropriate for the Fo factor of mixed fuels with variable
fuel ratios. The level of the emission rate relative to the compliance
level should be considered in determining if a retest is appropriate;
i.e., if the measured emissions are much lower or much greater than the
compliance limit, repetition of the test would not significantly change
the compliance status of the source and would be unnecessarily time
consuming and costly.
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
Same as Method 3, section 16.0.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
Table 3B-1--Fo Factors for Selected Fuels
------------------------------------------------------------------------
Fuel type Fo range
------------------------------------------------------------------------
Coal:
Anthracite and lignite.............................. 1.016-1.130
Bituminous.......................................... 1.083-1.230
Oil:
Distillate.......................................... 1.260-1.413
Residual............................................ 1.210-1.370
Gas:
Natural............................................. 1.600-1.836
Propane............................................. 1.434-1.586
Butane.............................................. 1.405-1.553
Wood.................................................... 1.000-1.120
Wood bark............................................... 1.003-1.130
------------------------------------------------------------------------
Method 3C--Determination of Carbon Dioxide, Methane, Nitrogen, and
Oxygen From Stationary Sources
1. Applicability and Principle
1.1 Applicability. This method applies to the analysis of carbon
dioxide (CO2), methane (CH4), nitrogen
(N2), and oxygen (O2) in samples from municipal
solid waste landfills and other sources when specified in an applicable
subpart.
1.2 Principle. A portion of the sample is injected into a gas
chromatograph (GC) and the CO2, CH4,
N2, and O2 concentrations are determined by using
a thermal conductivity detector (TCD) and integrator.
2. Range and Sensitivity
2.1 Range. The range of this method depends upon the concentration
of samples. The analytical range of TCD's is generally between
approximately 10 ppmv and the upper percent range.
2.2 Sensitivity. The sensitivity limit for a compound is defined as
the minimum detectable concentration of that compound, or the
concentration that produces a signal-to-noise ratio of three to one. For
CO2, CH4, N2, and O2, the
sensitivity limit is in the low ppmv range.
3. Interferences
Since the TCD exhibits universal response and detects all gas
components except the carrier, interferences may occur. Choosing the
appropriate GC or shifting the retention times by changing the column
flow rate may help to eliminate resolution interferences.
To assure consistent detector response, helium is used to prepare
calibration gases. Frequent exposure to samples or carrier gas
containing oxygen may gradually destroy filaments.
4. Apparatus
4.1 Gas Chromatograph. GC having at least the following components:
4.1.1 Separation Column. Appropriate column(s) to resolve
CO2, CH4, N2, O2, and other
gas components that may be present in the sample.
4.1.2 Sample Loop. Teflon or stainless steel tubing of the
appropriate diameter.
Note: Mention of trade names or specific products does not
constitute endorsement or recommendation by the U. S. Environmental
Protection Agency.
4.1.3 Conditioning System. To maintain the column and sample loop at
constant temperature.
4.1.4 Thermal Conductivity Detector.
4.2 Recorder. Recorder with linear strip chart. Electronic
integrator (optional) is recommended.
4.3 Teflon Tubing. Diameter and length determined by connection
requirements of cylinder regulators and the GC.
4.4 Regulators. To control gas cylinder pressures and flow rates.
4.5 Adsorption Tubes. Applicable traps to remove any O2
from the carrier gas.
5. Reagents
5.1 Calibration and Linearity Gases. Standard cylinder gas mixtures
for each compound of interest with at least three concentration levels
spanning the range of suspected sample concentrations. The calibration
gases shall be prepared in helium.
5.2 Carrier Gas. Helium, high-purity.
[[Page 156]]
6. Analysis
6.1 Sample Collection. Use the sample collection procedures
described in Methods 3 or 25C to collect a sample of landfill gas (LFG).
6.2 Preparation of GC. Before putting the GC analyzer into routine
operation, optimize the operational conditions according to the
manufacturer's specifications to provide good resolution and minimum
analysis time. Establish the appropriate carrier gas flow and set the
detector sample and reference cell flow rates at exactly the same
levels. Adjust the column and detector temperatures to the recommended
levels. Allow sufficient time for temperature stabilization. This may
typically require 1 hour for each change in temperature.
6.3 Analyzer Linearity Check and Calibration. Perform this test
before sample analysis.
6.3.1 Using the gas mixtures in section 5.1, verify the detector
linearity over the range of suspected sample concentrations with at
least three concentrations per compound of interest. This initial check
may also serve as the initial instrument calibration.
6.3.2 You may extend the use of the analyzer calibration by
performing a single-point calibration verification. Calibration
verifications shall be performed by triplicate injections of a single-
point standard gas. The concentration of the single-point calibration
must either be at the midpoint of the calibration curve or at
approximately the source emission concentration measured during
operation of the analyzer.
6.3.3 Triplicate injections must agree within 5 percent of their
mean, and the average calibration verification point must agree within
10 percent of the initial calibration response factor. If these
calibration verification criteria are not met, the initial calibration
described in section 6.3.1, using at least three concentrations, must be
repeated before analysis of samples can continue.
6.3.4 For each instrument calibration, record the carrier and
detector flow rates, detector filament and block temperatures,
attenuation factor, injection time, chart speed, sample loop volume, and
component concentrations.
6.3.5 Plot a linear regression of the standard concentrations versus
area values to obtain the response factor of each compound.
Alternatively, response factors of uncorrected component concentrations
(wet basis) may be generated using instrumental integration.
Note: Peak height may be used instead of peak area throughout this
method.
6.4 Sample Analysis. Purge the sample loop with sample, and allow to
come to atmospheric pressure before each injection. Analyze each sample
in duplicate, and calculate the average sample area (A). The results are
acceptable when the peak areas for two consecutive injections agree
within 5 percent of their average. If they do not agree, run additional
samples until consistent area data are obtained. Determine the tank
sample concentrations according to section 7.2.
7. Calculations
Carry out calculations retaining at least one extra decimal figure
beyond that of the acquired data. Round off results only after the final
calculation.
7.1 Nomenclature.
Bw = Moisture content in the sample, fraction.
CN2 = Measured N2 concentration (by Method 3C),
fraction.
CN2Corr = Measured N2 concentration corrected only
for dilution, fraction.
Ct = Calculated NMOC concentration, ppmv C equivalent.
Ctm = Measured NMOC concentration, ppmv C equivalent.
Pb = Barometric pressure, mm Hg.
Pt = Gas sample tank pressure after sampling, but before
pressurizing, mm Hg absolute.
Ptf = Final gas sample tank pressure after pressurizing, mm
Hg absolute.
Pti = Gas sample tank pressure after evacuation, mm Hg
absolute.
Pw = Vapor pressure of H2O (from Table 25C-1), mm
Hg.
r = Total number of analyzer injections of sample tank during analysis
(where j = injection number, 1 . . . r).
R = Mean calibration response factor for specific sample component,
area/ppm.
Tt = Sample tank temperature at completion of sampling,
[deg]K.
Tti = Sample tank temperature before sampling, [deg]K.
Ttf = Sample tank temperature after pressurizing, [deg]K.
7.2 Concentration of Sample Components. Calculate C for each
compound using Equations 3C-1 and 3C-2. Use the temperature and
barometric pressure at the sampling site to calculate Bw. If the sample
was diluted with helium using the procedures in Method 25C, use Equation
3C-3 to calculate the concentration.
[[Page 157]]
[GRAPHIC] [TIFF OMITTED] TR12MR96.031
7.3 Measured N2 Concentration Correction. Calculate the
reported N2 correction for Method 25-C using Eq. 3C-4. If
oxygen is determined in place of N2, substitute the oxygen
concentration for the nitrogen concentration in the equation.
[GRAPHIC] [TIFF OMITTED] TR27FE14.010
8. Bibliography
1. McNair, H.M., and E.J. Bonnelli. Basic Gas Chromatography.
Consolidated Printers, Berkeley, CA. 1969.
[36 FR 24877, Dec. 23, 1971]
Editorial Note: For Federal Register citations affecting appendix A-
2 to part 60, see the List of CFR sections Affected, which appears in
the Finding Aids section of the printed volume and at www.govinfo.gov.
Sec. Appendix A-3 to Part 60--Test Methods 4 through 5I
Method 4--Determination of moisture content in stack gases
Method 5--Determination of particulate matter emissions from stationary
sources
Method 5A--Determination of particulate matter emissions from the
asphalt processing and asphalt roofing industry
Method 5B--Determination of nonsulfuric acid particulate matter
emissions from stationary sources
Method 5C [Reserved]
Method 5D--Determination of particulate matter emissions from positive
pressure fabric filters
Method 5E--Determination of particulate matter emissions from the wool
fiberglass insulation manufacturing industry
Method 5F--Determination of nonsulfate particulate matter emissions from
stationary sources
Method 5G--Determination of particulate matter emissions from wood
heaters (dilution tunnel sampling location)
Method 5H--Determination of particulate emissions from wood heaters from
a stack location
Method 5I--Determination of Low Level Particulate Matter Emissions From
Stationary Sources
The test methods in this appendix are referred to in Sec. 60.8
(Performance Tests) and Sec. 60.11 (Compliance With Standards and
Maintenance Requirements) of 40 CFR part 60, subpart A (General
Provisions). Specific uses of these test methods are described in the
standards of performance contained in the subparts, beginning with
Subpart D.
Within each standard of performance, a section title ``Test Methods
and Procedures'' is provided to: (1) Identify the test methods to be
used as reference methods to the facility subject to the respective
standard and (2) identify any special instructions or conditions to be
followed when applying a method to the respective facility. Such
instructions (for example, establish sampling rates, volumes, or
temperatures) are to be used either in addition to, or as a substitute
for procedures in a test method. Similarly, for sources subject to
emission monitoring requirements, specific instructions pertaining to
any use of a test method as a reference
[[Page 158]]
method are provided in the subpart or in Appendix B.
Inclusion of methods in this appendix is not intended as an
endorsement or denial of their applicability to sources that are not
subject to standards of performance. The methods are potentially
applicable to other sources; however, applicability should be confirmed
by careful and appropriate evaluation of the conditions prevalent at
such sources.
The approach followed in the formulation of the test methods
involves specifications for equipment, procedures, and performance. In
concept, a performance specification approach would be preferable in all
methods because this allows the greatest flexibility to the user. In
practice, however, this approach is impractical in most cases because
performance specifications cannot be established. Most of the methods
described herein, therefore, involve specific equipment specifications
and procedures, and only a few methods in this appendix rely on
performance criteria.
Minor changes in the test methods should not necessarily affect the
validity of the results and it is recognized that alternative and
equivalent methods exist. section 60.8 provides authority for the
Administrator to specify or approve (1) equivalent methods, (2)
alternative methods, and (3) minor changes in the methodology of the
test methods. It should be clearly understood that unless otherwise
identified all such methods and changes must have prior approval of the
Administrator. An owner employing such methods or deviations from the
test methods without obtaining prior approval does so at the risk of
subsequent disapproval and retesting with approved methods.
Within the test methods, certain specific equipment or procedures
are recognized as being acceptable or potentially acceptable and are
specifically identified in the methods. The items identified as
acceptable options may be used without approval but must be identified
in the test report. The potentially approvable options are cited as
``subject to the approval of the Administrator'' or as ``or
equivalent.'' Such potentially approvable techniques or alternatives may
be used at the discretion of the owner without prior approval. However,
detailed descriptions for applying these potentially approvable
techniques or alternatives are not provided in the test methods. Also,
the potentially approvable options are not necessarily acceptable in all
applications. Therefore, an owner electing to use such potentially
approvable techniques or alternatives is responsible for: (1) assuring
that the techniques or alternatives are in fact applicable and are
properly executed; (2) including a written description of the
alternative method in the test report (the written method must be clear
and must be capable of being performed without additional instruction,
and the degree of detail should be similar to the detail contained in
the test methods); and (3) providing any rationale or supporting data
necessary to show the validity of the alternative in the particular
application. Failure to meet these requirements can result in the
Administrator's disapproval of the alternative.
Method 4--Determination of Moisture Content in Stack Gases
Note: This method does not include all the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling) essential to its
performance. Some material is incorporated by reference from other
methods in this part. Therefore, to obtain reliable results, persons
using this method should have a thorough knowledge of at least the
following additional test methods: Method 1, Method 5, and Method 6.
1.0 Scope and Application
1.1 Analytes.
------------------------------------------------------------------------
Analyte CAS No. Sensitivity
------------------------------------------------------------------------
Water vapor (H2O)................. 7732-18-5 N/A
------------------------------------------------------------------------
1.2 Applicability. This method is applicable for the determination
of the moisture content of stack gas.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 A gas sample is extracted at a constant rate from the source;
moisture is removed from the sample stream and determined either
volumetrically or gravimetrically.
2.2 The method contains two possible procedures: a reference method
and an approximation method.
2.2.1 The reference method is used for accurate determinations of
moisture content (such as are needed to calculate emission data). The
approximation method, provides estimates of percent moisture to aid in
setting isokinetic sampling rates prior to a pollutant emission
measurement run. The approximation method described herein is only a
suggested approach; alternative means for approximating the moisture
content (e.g., drying tubes, wet bulb-dry bulb techniques, condensation
techniques, stoichiometric calculations, previous experience, etc.) are
also acceptable.
2.2.2 The reference method is often conducted simultaneously with a
pollutant emission measurement run. When it is, calculation of percent
isokinetic, pollutant emission rate, etc., for the run shall be based
upon the results of the reference method or its equivalent. These
calculations shall not
[[Page 159]]
be based upon the results of the approximation method, unless the
approximation method is shown, to the satisfaction of the Administrator,
to be capable of yielding results within one percent H2O of
the reference method.
3.0 Definitions [Reserved]
4.0 Interferences
4.1 The moisture content of saturated gas streams or streams that
contain water droplets, as measured by the reference method, may be
positively biased. Therefore, when these conditions exist or are
suspected, a second determination of the moisture content shall be made
simultaneously with the reference method, as follows: Assume that the
gas stream is saturated. Attach a temperature sensor [capable of
measuring to 1 [deg]C (2 [deg]F)] to the reference
method probe. Measure the stack gas temperature at each traverse point
(see section 8.1.1.1) during the reference method traverse, and
calculate the average stack gas temperature. Next, determine the
moisture percentage, either by: (1) Using a psychrometric chart and
making appropriate corrections if the stack pressure is different from
that of the chart, or (2) using saturation vapor pressure tables. In
cases where the psychrometric chart or the saturation vapor pressure
tables are not applicable (based on evaluation of the process),
alternative methods, subject to the approval of the Administrator, shall
be used.
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and determine the applicability of regulatory limitations
prior to performing this test method.
6.0 Equipment and Supplies
6.1 Reference Method. A schematic of the sampling train used in this
reference method is shown in Figure 4-1.
6.1.1 Probe. Stainless steel or glass tubing, sufficiently heated to
prevent water condensation, and equipped with a filter, either in-stack
(e.g., a plug of glass wool inserted into the end of the probe) or
heated out-of-stack (e.g., as described in Method 5), to remove
particulate matter. When stack conditions permit, other metals or
plastic tubing may be used for the probe, subject to the approval of the
Administrator.
6.1.2 Condenser. Same as Method 5, section 6.1.1.8.
6.1.3 Cooling System. An ice bath container, crushed ice, and water
(or equivalent), to aid in condensing moisture.
6.1.4 Metering System. Same as in Method 5, section 6.1.1.9, except
do not use sampling systems designed for flow rates higher than 0.0283
m\3\/min (1.0 cfm). Other metering systems, capable of maintaining a
constant sampling rate to within 10 percent and determining sample gas
volume to within 2 percent, may be used, subject to the approval of the
Administrator.
6.1.5 Barometer and Graduated Cylinder and/or Balance. Same as
Method 5, sections 6.1.2 and 6.2.5, respectively.
6.2. Approximation Method. A schematic of the sampling train used in
this approximation method is shown in Figure 4-2.
6.2.1 Probe. Same as section 6.1.1.
6.2.2 Condenser. Two midget impingers, each with 30-ml capacity, or
equivalent.
6.2.3 Cooling System. Ice bath container, crushed ice, and water, to
aid in condensing moisture in impingers.
6.2.4 Drying Tube. Tube packed with new or regenerated 6- to 16-mesh
indicating-type silica gel (or equivalent desiccant), to dry the sample
gas and to protect the meter and pump.
6.2.5 Valve. Needle valve, to regulate the sample gas flow rate.
6.2.6 Pump. Leak-free, diaphragm type, or equivalent, to pull the
gas sample through the train.
6.2.7 Volume Meter. Dry gas meter, sufficiently accurate to measure
the sample volume to within 2 percent, and calibrated over the range of
flow rates and conditions actually encountered during sampling.
6.2.8 Rate Meter. Rotameter, or equivalent, to measure the flow
range from 0 to 3 liters/min (0 to 0.11 cfm).
6.2.9 Graduated Cylinder. 25-ml.
6.2.10 Barometer. Same as Method 5, section 6.1.2.
6.2.11 Vacuum Gauge. At least 760-mm (30-in.) Hg gauge, to be used
for the sampling leak check.
7.0 Reagents and Standards [Reserved]
8.0 Sample Collection, Preservation, Transport, and Storage
8.1 Reference Method. The following procedure is intended for a
condenser system (such as the impinger system described in section
6.1.1.8 of Method 5) incorporating volumetric analysis to measure the
condensed moisture, and silica gel and gravimetric analysis to measure
the moisture leaving the condenser.
8.1.1 Preliminary Determinations.
8.1.1.1 Unless otherwise specified by the Administrator, a minimum
of eight traverse points shall be used for circular stacks having
diameters less than 0.61 m (24 in.), a minimum of nine points shall be
used for rectangular stacks having equivalent diameters less than 0.61 m
(24 in.), and a minimum of twelve traverse points shall be used in all
[[Page 160]]
other cases. The traverse points shall be located according to Method 1.
The use of fewer points is subject to the approval of the Administrator.
Select a suitable probe and probe length such that all traverse points
can be sampled. Consider sampling from opposite sides of the stack (four
total sampling ports) for large stacks, to permit use of shorter probe
lengths. Mark the probe with heat resistant tape or by some other method
to denote the proper distance into the stack or duct for each sampling
point.
8.1.1.2 Select a total sampling time such that a minimum total gas
volume of 0.60 scm (21 scf) will be collected, at a rate no greater than
0.021 m\3\/min (0.75 cfm). When both moisture content and pollutant
emission rate are to be determined, the moisture determination shall be
simultaneous with, and for the same total length of time as, the
pollutant emission rate run, unless otherwise specified in an applicable
subpart of the standards.
8.1.2 Preparation of Sampling Train.
8.1.2.1 Place known volumes of water in the first two impingers;
alternatively, transfer water into the first two impingers and record
the weight of each impinger (plus water) to the nearest 0.5 g. Weigh and
record the weight of the silica gel to the nearest 0.5 g, and transfer
the silica gel to the fourth impinger; alternatively, the silica gel may
first be transferred to the impinger, and the weight of the silica gel
plus impinger recorded.
8.1.2.2 Set up the sampling train as shown in Figure 4-1. Turn on
the probe heater and (if applicable) the filter heating system to
temperatures of approximately 120 [deg]C (248 [deg]F), to prevent water
condensation ahead of the condenser. Allow time for the temperatures to
stabilize. Place crushed ice and water in the ice bath container.
8.1.3 Leak Check Procedures. It is recommended, but not required,
that the volume metering system and sampling train be leak-checked as
follows:
8.1.3.1 Metering System. Same as Method 5, section 8.4.1.
8.1.3.2 Sampling Train. Disconnect the probe from the first impinger
or (if applicable) from the filter holder. Plug the inlet to the first
impinger (or filter holder), and pull a 380 mm (15 in.) Hg vacuum. A
lower vacuum may be used, provided that it is not exceeded during the
test. A leakage rate in excess of 4 percent of the average sampling rate
or 0.00057 m\3\/min (0.020 cfm), whichever is less, is unacceptable.
Following the leak check, reconnect the probe to the sampling train.
8.1.4 Sampling Train Operation. During the sampling run, maintain a
sampling rate within 10 percent of constant rate, or as specified by the
Administrator. For each run, record the data required on a data sheet
similar to that shown in Figure 4-3. Be sure to record the dry gas meter
reading at the beginning and end of each sampling time increment and
whenever sampling is halted. Take other appropriate readings at each
sample point at least once during each time increment.
Note: When Method 4 is used concurrently with an isokinetic method
(e.g., Method 5) the sampling rate should be maintained at isokinetic
conditions rather than 10 percent of constant rate.
8.1.4.1 To begin sampling, position the probe tip at the first
traverse point. Immediately start the pump, and adjust the flow to the
desired rate. Traverse the cross section, sampling at each traverse
point for an equal length of time. Add more ice and, if necessary, salt
to maintain a temperature of less than 20 [deg]C (68 [deg]F) at the
silica gel outlet.
8.1.4.2 After collecting the sample, disconnect the probe from the
first impinger (or from the filter holder), and conduct a leak check
(mandatory) of the sampling train as described in section 8.1.3.2.
Record the leak rate. If the leakage rate exceeds the allowable rate,
either reject the test results or correct the sample volume as in
section 12.3 of Method 5.
8.2 Approximation Method.
Note: The approximation method described below is presented only as
a suggested method (see section 2.0).
8.2.1 Place exactly 5 ml water in each impinger. Leak check the
sampling train as follows: Temporarily insert a vacuum gauge at or near
the probe inlet. Then, plug the probe inlet and pull a vacuum of at
least 250 mm (10 in.) Hg. Note the time rate of change of the dry gas
meter dial; alternatively, a rotameter (0 to 40 ml/min) may be
temporarily attached to the dry gas meter outlet to determine the
leakage rate. A leak rate not in excess of 2 percent of the average
sampling rate is acceptable.
Note: Release the probe inlet plug slowly before turning off the
pump.
8.2.2 Connect the probe, insert it into the stack, and sample at a
constant rate of 2 liters/min (0.071 cfm). Continue sampling until the
dry gas meter registers about 30 liters (1.1 ft\3\) or until visible
liquid droplets are carried over from the first impinger to the second.
Record temperature, pressure, and dry gas meter readings as indicated by
Figure 4-4.
9.0 Quality Control
9.1 Miscellaneous Quality Control Measures.
[[Page 161]]
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
Section 8.1.1.4............. Leak rate of the Ensures the accuracy
sampling system of the volume of
cannot exceed four gas sampled.
percent of the (Reference Method).
average sampling
rate or 0.00057
m\3\/min (0.020
cfm).
Section 8.2.1............... Leak rate of the Ensures the accuracy
sampling system of the volume of
cannot exceed two gas sampled.
percent of the (Approximation
average sampling Method).
rate.
------------------------------------------------------------------------
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
10.0 Calibration and Standardization
Note: Maintain a laboratory log of all calibrations.
10.1 Reference Method. Calibrate the metering system, temperature
sensors, and barometer according to Method 5, sections 10.3, 10.5, and
10.6, respectively.
10.2 Approximation Method. Calibrate the metering system and the
barometer according to Method 6, section 10.1 and Method 5, section
10.6, respectively.
10.3 Field Balance Calibration Check. Check the calibration of the
balance used to weigh impingers with a weight that is at least 500g or
within 50g of a loaded impinger. The weight must be ASTM E617-13
``Standard Specification for Laboratory Weights and Precision Mass
Standards'' (incorporated by reference-see 40 CFR 60.17) Class 6 (or
better). Daily, before use, the field balance must measure the weight
within 0.5g of the certified mass. If the daily
balance calibration check fails, perform corrective measures and repeat
the check before using balance.
11.0 Analytical Procedure
11.1 Reference Method. Measure the volume of the moisture condensed
in each of the impingers to the nearest ml. Alternatively, if the
impingers were weighed prior to sampling, weigh the impingers after
sampling and record the difference in weight to the nearest 0.5 g.
Determine the increase in weight of the silica gel (or silica gel plus
impinger) to the nearest 0.5 g. Record this information (see example
data sheet, Figure 4-5), and calculate the moisture content, as
described in section 12.0.
11.2 Approximation Method. Combine the contents of the two
impingers, and measure the volume to the nearest 0.5 ml.
12.0 Data Analysis and Calculations
Carry out the following calculations, retaining at least one extra
significant figure beyond that of the acquired data. Round off figures
after final calculation.
12.1 Reference Method.
12.1.1 Nomenclature.
Bws = Proportion of water vapor, by volume, in the gas
stream.
Mw = Molecular weight of water, 18.0 g/g-mole (18.0 lb/lb-
mole).
Pm = Absolute pressure (for this method, same as barometric
pressure) at the dry gas meter, mm Hg (in. Hg).
Pstd = Standard absolute pressure, 760 mm Hg (29.92 in. Hg).
R = Ideal gas constant, 0.06236 (mm Hg)(m\3\)/(g-mole)([deg]K) for
metric units and 21.85 (in. Hg)(ft\3\)/(lb-mole)([deg]R) for
English units.
Tm = Absolute temperature at meter, [deg]K ([deg]R).
Tstd = Standard absolute temperature, 293 [deg]K (528
[deg]R).
Vf = Final volume of condenser water, ml.
Vi = Initial volume, if any, of condenser water, ml.
Vm = Dry gas volume measured by dry gas meter, dcm (dcf).
Vm(std) = Dry gas volume measured by the dry gas meter,
corrected to standard conditions, dscm (dscf).
Vwc(std) = Volume of water vapor condensed, corrected to
standard conditions, scm (scf).
Vwsg(std) = Volume of water vapor collected in silica gel,
corrected to standard conditions, scm (scf).
Wf = Final weight of silica gel or silica gel plus impinger,
g.
Wi = Initial weight of silica gel or silica gel plus
impinger, g.
Y = Dry gas meter calibration factor.
[Delta]Vm = Incremental dry gas volume measured by dry gas
meter at each traverse point, dcm (dcf).
[rho]w = Density of water, 0.9982 g/ml (0.002201 lb/ml).
12.1.2 Volume of Water Vapor Condensed.
[GRAPHIC] [TIFF OMITTED] TR17OC00.098
Where:
K1 = 0.001333 m\3\/ml for metric units,
= 0.04706 ft\3\/ml for English units.
12.1.3 Volume of Water Collected in Silica Gel.
[GRAPHIC] [TIFF OMITTED] TR17OC00.099
Where:
[[Page 162]]
K2 = 1.0 g/g for metric units,
= 453.6 g/lb for English units.
K3 = 0.001335 m\3\/g for metric units,
= 0.04715 ft\3\/g for English units.
12.1.4 Sample Gas Volume.
[GRAPHIC] [TIFF OMITTED] TR17OC00.100
Where:
K4 = 0.3855 [deg]K/mm Hg for metric units,
= 17.64 [deg]R/in. Hg for English units.
Note: If the post-test leak rate (Section 8.1.4.2) exceeds the
allowable rate, correct the value of Vm in Equation 4-3, as described in
section 12.3 of Method 5.
12.1.5 Moisture Content.
[GRAPHIC] [TIFF OMITTED] TR17OC00.101
12.1.6 Verification of Constant Sampling Rate. For each time
increment, determine the [Delta]Vm. Calculate the average. If
the value for any time increment differs from the average by more than
10 percent, reject the results, and repeat the run.
12.1.7 In saturated or moisture droplet-laden gas streams, two
calculations of the moisture content of the stack gas shall be made, one
using a value based upon the saturated conditions (see section 4.1), and
another based upon the results of the impinger analysis. The lower of
these two values of Bws shall be considered correct.
12.2 Approximation Method. The approximation method presented is
designed to estimate the moisture in the stack gas; therefore, other
data, which are only necessary for accurate moisture determinations, are
not collected. The following equations adequately estimate the moisture
content for the purpose of determining isokinetic sampling rate
settings.
12.2.1 Nomenclature.
Bwm = Approximate proportion by volume of water vapor in the
gas stream leaving the second impinger, 0.025.
Bws = Water vapor in the gas stream, proportion by volume.
Mw = Molecular weight of water, 18.0 g/g-mole (18.0 lb/lb-
mole).
Pm = Absolute pressure (for this method, same as barometric
pressure) at the dry gas meter, mm Hg (in. Hg).
Pstd = Standard absolute pressure, 760 mm Hg (29.92 in. Hg).
R = Ideal gas constant, 0.06236 [(mm Hg)(m\3\)]/[(g-mole)(K)] for metric
units and 21.85 [(in. Hg)(ft\3\)]/[(lb-mole)([deg]R)] for
English units.
Tm = Absolute temperature at meter, [deg]K ([deg]R).
Tstd = Standard absolute temperature, 293 [deg]K (528
[deg]R).
Vf = Final volume of impinger contents, ml.
Vi = Initial volume of impinger contents, ml.
Vm = Dry gas volume measured by dry gas meter, dcm (dcf).
Vm(std) = Dry gas volume measured by dry gas meter, corrected
to standard conditions, dscm (dscf).
Vwc(std) = Volume of water vapor condensed, corrected to
standard conditions, scm (scf).
Y = Dry gas meter calibration factor.
[rho]w = Density of water, 0.09982 g/ml (0.002201 lb/ml).
12.2.2 Volume of Water Vapor Collected.
[GRAPHIC] [TIFF OMITTED] TR17OC00.102
Where:
K5 = 0.001333 m\3\/ml for metric units,
= 0.04706 ft\3\/ml for English units.
12.2.3 Sample Gas Volume.
[GRAPHIC] [TIFF OMITTED] TR17OC00.103
Where:
K6 = 0.3855 [deg]K/mm Hg for metric units,
= 17.64 [deg]R/in. Hg for English units.
12.2.4 Approximate Moisture Content.
[GRAPHIC] [TIFF OMITTED] TR17OC00.104
[[Page 163]]
12.2.5 Using F-factors to determine approximate moisture for
estimating moisture content where no wet scrubber is being used, for the
purpose of determining isokinetic sampling rate settings with no fuel
sample, is acceptable using the average Fc or Fd
factor from Method 19 (see Method 19, section 12.3.1). If this option is
selected, calculate the approximate moisture as follows:
Bws = BH + BA+ BF
Where:
BA = Mole Fraction of moisture in the ambient air.
[GRAPHIC] [TIFF OMITTED] TR30AU16.004
Bws = Mole fraction of moisture in the stack gas.
Fd = Volume of dry combustion components per unit of heat
content at 0 percent oxygen, dscf/10\6\.
Btu (scm/J). See Table 19-2 in Method 19.
Fw = Volume of wet combustion components per unit of heat
content at 0 percent oxygen, wet.
scf/10\6\ Btu (scm/J). See Table 19-2 in Method 19.
%RH = Percent relative humidity (calibrated hygrometer acceptable),
percent.
PBar = Barometric pressure, in. Hg.
T = Ambient temperature, [deg]F.
W = Percent free water by weight, percent.
O2 = Percent oxygen in stack gas, dry basis, percent.
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Alternative Procedures
16.1 The procedure described in Method 5 for determining moisture
content is an acceptable alternative to Method 4.
16.2 The procedures in Method 6A for determining moisture is an
acceptable alternative to Method 4.
16.3 Method 320 is an acceptable alternative to Method 4 for
determining moisture.
16.4 Using F-factors to determine moisture is an acceptable
alternative to Method 4 for a combustion stack not using a scrubber, and
where a fuel sample is taken during the test run and analyzed for
development of an Fd factor (see Method 19, section 12.3.2),
and where stack O2 content is measured by Method 3A or 3B
during each test run. If this option is selected, calculate the moisture
content as follows:
Bws = BH + BA + BF
Where:
BA = Mole fraction of moisture in the ambient air.
[[Page 164]]
[GRAPHIC] [TIFF OMITTED] TR30AU16.005
Note: Values of BA should be between 0.00 and 0.06 with
common values being about 0.015.
BF = Mole fraction of moisture from free water in the fuel.
[GRAPHIC] [TIFF OMITTED] TR30AU16.006
Note: Free water in fuel is minimal for distillate oil and gases,
such as propane and natural gas, so this step may be omitted for those
fuels.
BH = Mole fraction of moisture from the hydrogen in the fuel.
[GRAPHIC] [TIFF OMITTED] TR30AU16.007
Bws = Mole fraction of moisture in the stack gas.
Fd = Volume of dry combustion components per unit of heat
content at 0 percent oxygen, dscf/10\6\ Btu (scm/J). Develop a
test specific Fd value using an integrated fuel
sample from each test run and Equation 19-13 in section 12.3.2
of Method 19.
Fw = Volume of wet combustion components per unit of heat
content at 0 percent oxygen, wet scf/10\6\ Btu (scm/J).
Develop a test specific Fw value using an
integrated fuel sample from each test run and Equation 19-14
in section 12.3.2 of Method 19.
%RH = Percent relative humidity (calibrated hygrometer acceptable),
percent.
PBar = Barometric pressure, in. Hg.
T = Ambient temperature, [deg]F.
W = Percent free water by weight, percent.
O2 = Percent oxygen in stack gas, dry basis, percent.
17.0 References
1. Air Pollution Engineering Manual (Second Edition). Danielson,
J.A. (ed.). U.S. Environmental Protection Agency, Office of Air Quality
Planning and Standards. Research Triangle Park, NC. Publication No. AP-
40. 1973.
2. Devorkin, Howard, et al. Air Pollution Source Testing Manual. Air
Pollution Control District, Los Angeles, CA. November 1963.
3. Methods for Determination of Velocity, Volume, Dust and Mist
Content of Gases. Western Precipitation Division of Joy Manufacturing
Co. Los Angeles, CA. Bulletin WP-50. 1968.
18.0 Tables, Diagrams, Flowcharts, and Validation Data
[[Page 165]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.105
[[Page 166]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.106
[[Page 167]]
Plant___________________________________________________________________
Location________________________________________________________________
Operator________________________________________________________________
Date____________________________________________________________________
Run No._________________________________________________________________
Ambient temperature_____________________________________________________
Barometric pressure_____________________________________________________
Probe Length____________________________________________________________
------------------------------------------------------------------------
-------------------------------------------------------------------------
------------------------------------------------------------------------
[[Page 168]]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gas sample temperature Temperature
Pressure at dry gas meter of gas
Sampling Stack differential Meter -------------------------- leaving
time temperature across reading gas [Delta]Vm condenser
Traverse Pt. No. ([Delta]), [deg]C ( orifice sample m\3\ Inlet Tmin Outlet or last
min [deg]F) meter volume m\3\ (ft\3\) [deg]C ( Tmout impinger
[Delta]H mm (ft\3\) [deg]F) [deg]C ( [deg]C (
(in.) H2O [deg]F) [deg]F)
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------
Average
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 169]]
Location________________________________________________________________
Test____________________________________________________________________
Date____________________________________________________________________
Operator________________________________________________________________
Barometric pressure_____________________________________________________
Comments:_______________________________________________________________
________________________________________________________________________
Figure 4-3. Moisture Determination--Reference Method
----------------------------------------------------------------------------------------------------------------
Gas Volume through
Clock time meter, (Vm), m\3\ Rate meter setting m\3\/ Meter temperature
(ft\3\) min (ft\3\/min) [deg]C ( [deg]F)
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Figure 4-4. Example Moisture Determination Field Data Sheet--
Approximation Method
------------------------------------------------------------------------
Impinger volume, Silica gel weight,
ml g
------------------------------------------------------------------------
Final
Initial
Difference
------------------------------------------------------------------------
Figure 4-5. Analytical Data--Reference Method
Method 5--Determination of Particulate Matter Emissions From Stationary
Sources
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 2, Method 3.
1.0 Scope and Application
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the determination
of PM emissions from stationary sources.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
Particulate matter is withdrawn isokinetically from the source and
collected on a glass fiber filter maintained at a temperature of 120
14 [deg]C (248 25 [deg]F) or
such other temperature as specified by an applicable subpart of the
standards or approved by the Administrator for a particular application.
The PM mass, which includes any material that condenses at or above the
filtration temperature, is determined gravimetrically after the removal
of uncombined water.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and to determine the applicability of regulatory limitations
prior to performing this test method.
6.0 Equipment and Supplies
6.1 Sample Collection. The following items are required for sample
collection:
6.1.1 Sampling Train. A schematic of the sampling train used in this
method is shown in Figure 5-1 in section 18.0. Complete construction
details are given in APTD-0581 (Reference 2 in section 17.0); commercial
models of this train are also available. For
[[Page 170]]
changes from APTD-0581 and for allowable modifications of the train
shown in Figure 5-1, see the following subsections.
Note: The operating and maintenance procedures for the sampling
train are described in APTD-0576 (Reference 3 in section 17.0). Since
correct usage is important in obtaining valid results, all users should
read APTD-0576 and adopt the operating and maintenance procedures
outlined in it, unless otherwise specified herein.
6.1.1.1 Probe Nozzle. Stainless steel (316) or glass with a sharp,
tapered leading edge. The angle of taper shall be <=30[deg], and the
taper shall be on the outside to preserve a constant internal diameter.
The probe nozzle shall be of the button-hook or elbow design, unless
otherwise specified by the Administrator. If made of stainless steel,
the nozzle shall be constructed from seamless tubing. Other materials of
construction may be used, subject to the approval of the Administrator.
A range of nozzle sizes suitable for isokinetic sampling should be
available. Typical nozzle sizes range from 0.32 to 1.27 cm (\1/8\ to \1/
2\ in) inside diameter (ID) in increments of 0.16 cm (\1/16\ in). Larger
nozzles sizes are also available if higher volume sampling trains are
used. Each nozzle shall be calibrated, according to the procedures
outlined in section 10.1.
6.1.1.2 Probe Liner. Borosilicate or quartz glass tubing with a
heating system capable of maintaining a probe gas temperature during
sampling of 120 14 [deg]C (248 25 [deg]F), or such other temperature as specified by an
applicable subpart of the standards or as approved by the Administrator
for a particular application. Since the actual temperature at the outlet
of the probe is not usually monitored during sampling, probes
constructed according to APTD-0581 and utilizing the calibration curves
of APTD-0576 (or calibrated according to the procedure outlined in APTD-
0576) will be considered acceptable. Either borosilicate or quartz glass
probe liners may be used for stack temperatures up to about 480 [deg]C
(900 [deg]F); quartz glass liners shall be used for temperatures between
480 and 900 [deg]C (900 and 1,650 [deg]F). Both types of liners may be
used at higher temperatures than specified for short periods of time,
subject to the approval of the Administrator. The softening temperature
for borosilicate glass is 820 [deg]C (1500 [deg]F), and for quartz glass
it is 1500 [deg]C (2700 [deg]F). Whenever practical, every effort should
be made to use borosilicate or quartz glass probe liners. Alternatively,
metal liners (e.g., 316 stainless steel, Incoloy 825 or other corrosion
resistant metals) made of seamless tubing may be used, subject to the
approval of the Administrator.
6.1.1.3 Pitot Tube. Type S, as described in section 6.1 of Method 2,
or other device approved by the Administrator. The pitot tube shall be
attached to the probe (as shown in Figure 5-1) to allow constant
monitoring of the stack gas velocity. The impact (high pressure) opening
plane of the pitot tube shall be even with or above the nozzle entry
plane (see Method 2, Figure 2-7) during sampling. The Type S pitot tube
assembly shall have a known coefficient, determined as outlined in
section 10.0 of Method 2.
6.1.1.4 Differential Pressure Gauge. Inclined manometer or
equivalent device (two), as described in section 6.2 of Method 2. One
manometer shall be used for velocity head ([Delta]p) readings, and the
other, for orifice differential pressure readings.
6.1.1.5 Filter Holder. Borosilicate glass, with a glass or Teflon
frit filter support and a silicone rubber gasket. Other materials of
construction (e.g., stainless steel or Viton) may be used, subject to
the approval of the Administrator. The holder design shall provide a
positive seal against leakage from the outside or around the filter. The
holder shall be attached immediately at the outlet of the probe (or
cyclone, if used).
6.1.1.6 Filter Heating System. Any heating system capable of
monitoring and maintaining temperature around the filter shall be used
to ensure the sample gas temperature exiting the filter of 120 14 [deg]C (248 25 [deg]F) during
sampling or such other temperature as specified by an applicable subpart
of the standards or approved by the Administrator for a particular
application. The monitoring and regulation of the temperature around the
filter may be done with the filter temperature sensor or another
temperature sensor.
6.1.1.7 Filter Temperature Sensor. A temperature sensor capable of
measuring temperature to within 3 [deg]C (5.4
[deg]F) shall be installed so that the sensing tip of the temperature
sensor is in direct contact with the sample gas exiting the filter. The
sensing tip of the sensor may be encased in glass, Teflon, or metal and
must protrude at least \1/2\ in. into the sample gas exiting the filter.
The filter temperature sensor must be monitored and recorded during
sampling to ensure a sample gas temperature exiting the filter of 120
14 [deg]C (248 25 [deg]F),
or such other temperature as specified by an applicable subpart of the
standards or approved by the Administrator for a particular application.
6.1.1.8 Condenser. The following system shall be used to determine
the stack gas moisture content: Four impingers connected in series with
leak-free ground glass fittings or any similar leak-free
noncontaminating fittings. The first, third, and fourth impingers shall
be of the Greenburg-Smith design, modified by replacing the tip with a
1.3 cm (\1/2\ in.) ID glass tube extending to about 1.3 cm (\1/2\ in.)
from the bottom of the flask. The second impinger shall be of the
Greenburg-Smith design with the standard
[[Page 171]]
tip. Modifications (e.g., using flexible connections between the
impingers, using materials other than glass, or using flexible vacuum
lines to connect the filter holder to the condenser) may be used,
subject to the approval of the Administrator. The first and second
impingers shall contain known quantities of water (Section 8.3.1), the
third shall be empty, and the fourth shall contain a known weight of
silica gel, or equivalent desiccant. A temperature sensor, capable of
measuring temperature to within 1 [deg]C (2 [deg]F) shall be placed at
the outlet of the fourth impinger for monitoring purposes.
Alternatively, any system that cools the sample gas stream and allows
measurement of the water condensed and moisture leaving the condenser,
each to within 1 ml or 1 g may be used, subject to the approval of the
Administrator. An acceptable technique involves the measurement of
condensed water either gravimetrically or volumetrically and the
determination of the moisture leaving the condenser by: (1) monitoring
the temperature and pressure at the exit of the condenser and using
Dalton's law of partial pressures; or (2) passing the sample gas stream
through a tared silica gel (or equivalent desiccant) trap with exit
gases kept below 20 [deg]C (68 [deg]F) and determining the weight gain.
If means other than silica gel are used to determine the amount of
moisture leaving the condenser, it is recommended that silica gel (or
equivalent) still be used between the condenser system and pump to
prevent moisture condensation in the pump and metering devices and to
avoid the need to make corrections for moisture in the metered volume.
Note: If a determination of the PM collected in the impingers is
desired in addition to moisture content, the impinger system described
above shall be used, without modification. Individual States or control
agencies requiring this information shall be contacted as to the sample
recovery and analysis of the impinger contents.
6.1.1.9 Metering System. Vacuum gauge, leak-free pump, calibrated
temperature sensors, dry gas meter (DGM) capable of measuring volume to
within 2 percent, and related equipment, as shown in Figure 5-1. Other
metering systems capable of maintaining sampling rates within 10 percent
of isokinetic and of determining sample volumes to within 2 percent may
be used, subject to the approval of the Administrator. When the metering
system is used in conjunction with a pitot tube, the system shall allow
periodic checks of isokinetic rates. The average DGM temperature for use
in the calculations of section 12.0 may be obtained by averaging the two
temperature sensors located at the inlet and outlet of the DGM as shown
in Figure 5-3 or alternatively from a single temperature sensor located
at the immediate outlet of the DGM or the plenum of the DGM.
6.1.1.10 Sampling trains utilizing metering systems designed for
higher flow rates than that described in APTD-0581 or APTD-0576 may be
used provided that the specifications of this method are met.
6.1.2 Barometer. Mercury, aneroid, or other barometer capable of
measuring atmospheric pressure to within 2.5 mm Hg (0.1 in.).
Note: The barometric pressure reading may be obtained from a nearby
National Weather Service station. In this case, the station value (which
is the absolute barometric pressure) shall be requested and an
adjustment for elevation differences between the weather station and
sampling point shall be made at a rate of minus 2.5 mm Hg (0.1 in.) per
30 m (100 ft) elevation increase or plus 2.5 mm Hg (0.1 in) per 30 m
(100 ft) elevation decrease.
6.1.3 Gas Density Determination Equipment. Temperature sensor and
pressure gauge, as described in sections 6.3 and 6.4 of Method 2, and
gas analyzer, if necessary, as described in Method 3. The temperature
sensor shall, preferably, be permanently attached to the pitot tube or
sampling probe in a fixed configuration, such that the tip of the sensor
extends beyond the leading edge of the probe sheath and does not touch
any metal. Alternatively, the sensor may be attached just prior to use
in the field. Note, however, that if the temperature sensor is attached
in the field, the sensor must be placed in an interference-free
arrangement with respect to the Type S pitot tube openings (see Method
2, Figure 2-4). As a second alternative, if a difference of not more
than 1 percent in the average velocity measurement is to be introduced,
the temperature sensor need not be attached to the probe or pitot tube.
(This alternative is subject to the approval of the Administrator.)
6.2 Sample Recovery. The following items are required for sample
recovery:
6.2.1 Probe-Liner and Probe-Nozzle Brushes. Nylon bristle brushes
with stainless steel wire handles. The probe brush shall have extensions
(at least as long as the probe) constructed of stainless steel, Nylon,
Teflon, or similarly inert material. The brushes shall be properly sized
and shaped to brush out the probe liner and nozzle.
6.2.2 Wash Bottles. Two Glass wash bottles are recommended.
Alternatively, polyethylene wash bottles may be used. It is recommended
that acetone not be stored in polyethylene bottles for longer than a
month.
6.2.3 Glass Sample Storage Containers. Chemically resistant,
borosilicate glass bottles, for acetone washes, 500 ml or 1000 ml. Screw
cap liners shall either be rubber-backed Teflon or shall be constructed
so as
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to be leak-free and resistant to chemical attack by acetone. (Narrow
mouth glass bottles have been found to be less prone to leakage.)
Alternatively, polyethylene bottles may be used.
6.2.4 Petri Dishes. For filter samples; glass or polyethylene,
unless otherwise specified by the Administrator.
6.2.5 Graduated Cylinder and/or Balance. To measure condensed water
to within 1 ml or 0.5 g. Graduated cylinders shall have subdivisions no
greater than 2 ml.
6.2.6 Plastic Storage Containers. Air-tight containers to store
silica gel.
6.2.7 Funnel and Rubber Policeman. To aid in transfer of silica gel
to container; not necessary if silica gel is weighed in the field.
6.2.8 Funnel. Glass or polyethylene, to aid in sample recovery.
6.3 Sample Analysis. The following equipment is required for sample
analysis:
6.3.1 Glass Weighing Dishes.
6.3.2 Desiccator.
6.3.3 Analytical Balance. To measure to within 0.1 mg.
6.3.4 Balance. To measure to within 0.5 g.
6.3.5 Beakers. 250 ml.
6.3.6 Hygrometer. To measure the relative humidity of the laboratory
environment.
6.3.7 Temperature Sensor. To measure the temperature of the
laboratory environment.
7.0 Reagents and Standards
7.1 Sample Collection. The following reagents are required for
sample collection:
7.1.1 Filters. Glass fiber filters, without organic binder,
exhibiting at least 99.95 percent efficiency (<0.05 percent penetration)
on 0.3 micron dioctyl phthalate smoke particles. The filter efficiency
test shall be conducted in accordance with ASTM Method D 2986-71, 78, or
95a (incorporated by reference--see Sec. 60.17). Test data from the
supplier's quality control program are sufficient for this purpose. In
sources containing SO2 or SO3, the filter material
must be of a type that is unreactive to SO2 or
SO3. Reference 10 in section 17.0 may be used to select the
appropriate filter.
7.1.2 Silica Gel. Indicating type, 6 to 16 mesh. If previously used,
dry at 175 [deg]C (350 [deg]F) for 2 hours. New silica gel may be used
as received. Alternatively, other types of desiccants (equivalent or
better) may be used, subject to the approval of the Administrator.
7.1.3 Water. When analysis of the material caught in the impingers
is required, deionized distilled water [to conform to ASTM D1193-77 or
91 Type 3 (incorporated by reference--see Sec. 60.17)] with at least
<0.001 percent residue shall be used or as specified in the applicable
method requiring analysis of the water. Run reagent blanks prior to
field use to eliminate a high blank on test samples.
7.1.4 Crushed Ice.
7.2 Sample Recovery. Acetone, reagent grade, <=0.001 percent
residue, in glass bottles, is required. Acetone from metal containers
generally has a high residue blank and should not be used. Sometimes,
suppliers transfer acetone to glass bottles from metal containers; thus,
acetone blanks shall be run prior to field use and only acetone with low
blank values (<=0.001 percent) shall be used. In no case shall a blank
value of greater than 0.001 percent of the weight of acetone used be
subtracted from the sample weight.
7.3 Sample Analysis. The following reagents are required for sample
analysis:
7.3.1 Acetone. Same as in section 7.2.
7.3.2 Desiccant. Anhydrous calcium sulfate, indicating type.
Alternatively, other types of desiccants may be used, subject to the
approval of the Administrator.
8.0 Sample Collection, Preservation, Storage, and Transport
8.1 Pretest Preparation. It is suggested that sampling equipment be
maintained according to the procedures described in APTD-0576.
Alternative mercury-free thermometers may be used if the thermometers
are at a minimum equivalent in terms of performance or suitably
effective for the specific temperature measurement application.
8.1.1 Place 200 to 300 g of silica gel in each of several air-tight
containers. Weigh each container, including silica gel, to the nearest
0.5 g, and record this weight. As an alternative, the silica gel need
not be preweighed, but may be weighed directly in its impinger or
sampling holder just prior to train assembly.
8.1.2 Check filters visually against light for irregularities,
flaws, or pinhole leaks. Label filters of the proper diameter on the
back side near the edge using numbering machine ink. As an alternative,
label the shipping containers (glass or polyethylene petri dishes), and
keep each filter in its identified container at all times except during
sampling.
8.1.3 Desiccate the filters at 20 5.6 [deg]C
(68 10 [deg]F) and ambient pressure for at least
24 hours. Weigh each filter (or filter and shipping container) at
intervals of at least 6 hours to a constant weight (i.e., <=0.5 mg
change from previous weighing). Record results to the nearest 0.1 mg.
During each weighing, the period for which the filter is exposed to the
laboratory atmosphere shall be less than 2 minutes. Alternatively
(unless otherwise specified by the Administrator), the filters may be
oven dried at 105 [deg]C (220 [deg]F) for 2 to 3 hours, desiccated for 2
hours, and weighed. Procedures other than those described, which account
for relative humidity effects, may be used, subject to the approval of
the Administrator.
8.2 Preliminary Determinations.
8.2.1 Select the sampling site and the minimum number of sampling
points according
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to Method 1 or as specified by the Administrator. Determine the stack
pressure, temperature, and the range of velocity heads using Method 2;
it is recommended that a leak check of the pitot lines (see Method 2,
section 8.1) be performed. Determine the moisture content using
Approximation Method 4 or its alternatives for the purpose of making
isokinetic sampling rate settings. Determine the stack gas dry molecular
weight, as described in Method 2, section 8.6; if integrated Method 3
sampling is used for molecular weight determination, the integrated bag
sample shall be taken simultaneously with, and for the same total length
of time as, the particulate sample run.
8.2.2 Select a nozzle size based on the range of velocity heads,
such that it is not necessary to change the nozzle size in order to
maintain isokinetic sampling rates. During the run, do not change the
nozzle size. Ensure that the proper differential pressure gauge is
chosen for the range of velocity heads encountered (see section 8.3 of
Method 2).
8.2.3 Select a suitable probe liner and probe length such that all
traverse points can be sampled. For large stacks, consider sampling from
opposite sides of the stack to reduce the required probe length.
8.2.4 Select a total sampling time greater than or equal to the
minimum total sampling time specified in the test procedures for the
specific industry such that (l) the sampling time per point is not less
than 2 minutes (or some greater time interval as specified by the
Administrator), and (2) the sample volume taken (corrected to standard
conditions) will exceed the required minimum total gas sample volume.
The latter is based on an approximate average sampling rate.
8.2.5 The sampling time at each point shall be the same. It is
recommended that the number of minutes sampled at each point be an
integer or an integer plus one-half minute, in order to avoid
timekeeping errors.
8.2.6 In some circumstances (e.g., batch cycles) it may be necessary
to sample for shorter times at the traverse points and to obtain smaller
gas sample volumes. In these cases, the Administrator's approval must
first be obtained.
8.3 Preparation of Sampling Train.
8.3.1 During preparation and assembly of the sampling train, keep
all openings where contamination can occur covered until just prior to
assembly or until sampling is about to begin. Place 100 ml of water in
each of the first two impingers, leave the third impinger empty, and
transfer approximately 200 to 300 g of preweighed silica gel from its
container to the fourth impinger. More silica gel may be used, but care
should be taken to ensure that it is not entrained and carried out from
the impinger during sampling. Place the container in a clean place for
later use in the sample recovery. Alternatively, the weight of the
silica gel plus impinger may be determined to the nearest 0.5 g and
recorded.
8.3.2 Using a tweezer or clean disposable surgical gloves, place a
labeled (identified) and weighed filter in the filter holder. Be sure
that the filter is properly centered and the gasket properly placed so
as to prevent the sample gas stream from circumventing the filter. Check
the filter for tears after assembly is completed.
8.3.3 When glass probe liners are used, install the selected nozzle
using a Viton A O-ring when stack temperatures are less than 260 [deg]C
(500 [deg]F) or a heat-resistant string gasket when temperatures are
higher. See APTD-0576 for details. Other connecting systems using either
316 stainless steel or Teflon ferrules may be used. When metal liners
are used, install the nozzle as discussed above or by a leak-free direct
mechanical connection. Mark the probe with heat resistant tape or by
some other method to denote the proper distance into the stack or duct
for each sampling point.
8.3.4 Set up the train as shown in Figure 5-1 ensuring that the
connections are leak-tight. Subject to the approval of the
Administrator, a glass cyclone may be used between the probe and filter
holder when the total particulate catch is expected to exceed 100 mg or
when water droplets are present in the stack gas.
8.3.5 Place crushed ice around the impingers.
8.4 Leak-Check Procedures.
8.4.1 Leak Check of Metering System Shown in Figure 5-1. That
portion of the sampling train from the pump to the orifice meter should
be leak-checked prior to initial use and after each shipment. Leakage
after the pump will result in less volume being recorded than is
actually sampled. The following procedure is suggested (see Figure 5-2):
Close the main valve on the meter box. Insert a one-hole rubber stopper
with rubber tubing attached into the orifice exhaust pipe. Disconnect
and vent the low side of the orifice manometer. Close off the low side
orifice tap. Pressurize the system to 13 to 18 cm (5 to 7 in.) water
column by blowing into the rubber tubing. Pinch off the tubing, and
observe the manometer for one minute. A loss of pressure on the
manometer indicates a leak in the meter box; leaks, if present, must be
corrected.
8.4.2 Pretest Leak Check. A pretest leak check of the sampling train
is recommended, but not required. If the pretest leak check is
conducted, the following procedure should be used.
8.4.2.1 After the sampling train has been assembled, turn on and set
the filter and probe heating systems to the desired operating
temperatures. Allow time for the temperatures to stabilize. If a Viton A
O-ring or
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other leak-free connection is used in assembling the probe nozzle to the
probe liner, leak-check the train at the sampling site by plugging the
nozzle and pulling a 380 mm (15 in.) Hg vacuum.
Note: A lower vacuum may be used, provided that it is not exceeded
during the test.
8.4.2.2 If a heat-resistant string is used, do not connect the probe
to the train during the leak check. Instead, leak-check the train by
first plugging the inlet to the filter holder (cyclone, if applicable)
and pulling a 380 mm (15 in.) Hg vacuum (see note in section 8.4.2.1).
Then connect the probe to the train, and leak-check at approximately 25
mm (1 in.) Hg vacuum; alternatively, the probe may be leak-checked with
the rest of the sampling train, in one step, at 380 mm (15 in.) Hg
vacuum. Leakage rates in excess of 4 percent of the average sampling
rate or 0.00057 m\3\/min (0.020 cfm), whichever is less, are
unacceptable.
8.4.2.3 The following leak-check instructions for the sampling train
described in APTD-0576 and APTD-0581 may be helpful. Start the pump with
the bypass valve fully open and the coarse adjust valve completely
closed. Partially open the coarse adjust valve, and slowly close the
bypass valve until the desired vacuum is reached. Do not reverse the
direction of the bypass valve, as this will cause water to back up into
the filter holder. If the desired vacuum is exceeded, either leak-check
at this higher vacuum, or end the leak check and start over.
8.4.2.4 When the leak check is completed, first slowly remove the
plug from the inlet to the probe, filter holder, or cyclone (if
applicable), and immediately turn off the vacuum pump. This prevents the
water in the impingers from being forced backward into the filter holder
and the silica gel from being entrained backward into the third
impinger.
8.4.3 Leak Checks During Sample Run. If, during the sampling run, a
component (e.g., filter assembly or impinger) change becomes necessary,
a leak check shall be conducted immediately before the change is made.
The leak check shall be done according to the procedure outlined in
section 8.4.2 above, except that it shall be done at a vacuum equal to
or greater than the maximum value recorded up to that point in the test.
If the leakage rate is found to be no greater than 0.00057 m\3\/min
(0.020 cfm) or 4 percent of the average sampling rate (whichever is
less), the results are acceptable, and no correction will need to be
applied to the total volume of dry gas metered; if, however, a higher
leakage rate is obtained, either record the leakage rate and plan to
correct the sample volume as shown in section 12.3 of this method, or
void the sample run.
Note: Immediately after component changes, leak checks are optional.
If such leak checks are done, the procedure outlined in section 8.4.2
above should be used.
8.4.4 Post-Test Leak Check. A leak check of the sampling train is
mandatory at the conclusion of each sampling run. The leak check shall
be performed in accordance with the procedures outlined in section
8.4.2, except that it shall be conducted at a vacuum equal to or greater
than the maximum value reached during the sampling run. If the leakage
rate is found to be no greater than 0.00057 m\3\ min (0.020 cfm) or 4
percent of the average sampling rate (whichever is less), the results
are acceptable, and no correction need be applied to the total volume of
dry gas metered. If, however, a higher leakage rate is obtained, either
record the leakage rate and correct the sample volume as shown in
section 12.3 of this method, or void the sampling run.
8.5 Sampling Train Operation. During the sampling run, maintain an
isokinetic sampling rate (within 10 percent of true isokinetic unless
otherwise specified by the Administrator) and a sample gas temperature
through the filter of 120 14 [deg]C (248 25 [deg]F) or such other temperature as specified by an
applicable subpart of the standards or approved by the Administrator.
8.5.1 For each run, record the data required on a data sheet such as
the one shown in Figure 5-3. Be sure to record the initial DGM reading.
Record the DGM readings at the beginning and end of each sampling time
increment, when changes in flow rates are made, before and after each
leak check, and when sampling is halted. Take other readings indicated
by Figure 5-3 at least once at each sample point during each time
increment and additional readings when significant changes (20 percent
variation in velocity head readings) necessitate additional adjustments
in flow rate. Level and zero the manometer. Because the manometer level
and zero may drift due to vibrations and temperature changes, make
periodic checks during the traverse.
8.5.2 Clean the portholes prior to the test run to minimize the
chance of collecting deposited material. To begin sampling, verify that
the filter and probe heating systems are up to temperature, remove the
nozzle cap, verify that the pitot tube and probe are properly
positioned. Position the nozzle at the first traverse point with the tip
pointing directly into the gas stream. Immediately start the pump, and
adjust the flow to isokinetic conditions. Nomographs are available which
aid in the rapid adjustment of the isokinetic sampling rate without
excessive computations. These nomographs are designed for use when the
Type S pitot tube coefficient (Cp) is 0.85 0.02, and the stack gas equivalent density [dry
molecular weight (Md)] is equal to 29 4. APTD-0576 details the procedure for using the
nomographs. If Cp and Md are outside the above
stated ranges,
[[Page 175]]
do not use the nomographs unless appropriate steps (see Reference 7 in
section 17.0) are taken to compensate for the deviations.
8.5.3 When the stack is under significant negative pressure (i.e.,
height of impinger stem), take care to close the coarse adjust valve
before inserting the probe into the stack to prevent water from backing
into the filter holder. If necessary, the pump may be turned on with the
coarse adjust valve closed.
8.5.4 When the probe is in position, block off the openings around
the probe and porthole to prevent unrepresentative dilution of the gas
stream.
8.5.5 Traverse the stack cross-section, as required by Method 1 or
as specified by the Administrator, being careful not to bump the probe
nozzle into the stack walls when sampling near the walls or when
removing or inserting the probe through the portholes; this minimizes
the chance of extracting deposited material.
8.5.6 During the test run, make periodic adjustments to keep the
temperature around the filter holder at the proper level to maintain the
sample gas temperature exiting the filter; add more ice and, if
necessary, salt to maintain a temperature of less than 20 [deg]C (68
[deg]F) at the condenser/silica gel outlet. Also, periodically check the
level and zero of the manometer.
8.5.7 If the pressure drop across the filter becomes too high,
making isokinetic sampling difficult to maintain, the filter may be
replaced in the midst of the sample run. It is recommended that another
complete filter assembly be used rather than attempting to change the
filter itself. Before a new filter assembly is installed, conduct a leak
check (see section 8.4.3). The total PM weight shall include the
summation of the filter assembly catches.
8.5.8 A single train shall be used for the entire sample run, except
in cases where simultaneous sampling is required in two or more separate
ducts or at two or more different locations within the same duct, or in
cases where equipment failure necessitates a change of trains. In all
other situations, the use of two or more trains will be subject to the
approval of the Administrator.
Note: When two or more trains are used, separate analyses of the
front-half and (if applicable) impinger catches from each train shall be
performed, unless identical nozzle sizes were used on all trains, in
which case, the front-half catches from the individual trains may be
combined (as may the impinger catches) and one analysis of front-half
catch and one analysis of impinger catch may be performed. Consult with
the Administrator for details concerning the calculation of results when
two or more trains are used.
8.5.9 At the end of the sample run, close the coarse adjust valve,
remove the probe and nozzle from the stack, turn off the pump, record
the final DGM meter reading, and conduct a post-test leak check, as
outlined in section 8.4.4. Also, leak-check the pitot lines as described
in Method 2, section 8.1. The lines must pass this leak check, in order
to validate the velocity head data.
8.6 Calculation of Percent Isokinetic. Calculate percent isokinetic
(see Calculations, section 12.11) to determine whether the run was valid
or another test run should be made. If there was difficulty in
maintaining isokinetic rates because of source conditions, consult with
the Administrator for possible variance on the isokinetic rates.
8.7 Sample Recovery.
8.7.1 Proper cleanup procedure begins as soon as the probe is
removed from the stack at the end of the sampling period. Allow the
probe to cool.
8.7.2 When the probe can be safely handled, wipe off all external PM
near the tip of the probe nozzle, and place a cap over it to prevent
losing or gaining PM. Do not cap off the probe tip tightly while the
sampling train is cooling down. This would create a vacuum in the filter
holder, thereby drawing water from the impingers into the filter holder.
8.7.3 Before moving the sample train to the cleanup site, remove the
probe from the sample train and cap the open outlet of the probe. Be
careful not to lose any condensate that might be present. Cap the filter
inlet where the probe was fastened. Remove the umbilical cord from the
last impinger, and cap the impinger. If a flexible line is used between
the first impinger or condenser and the filter holder, disconnect the
line at the filter holder, and let any condensed water or liquid drain
into the impingers or condenser. Cap off the filter holder outlet and
impinger inlet. Either ground-glass stoppers, plastic caps, or serum
caps may be used to close these openings.
8.7.4 Transfer the probe and filter-impinger assembly to the cleanup
area. This area should be clean and protected from the wind so that the
chances of contaminating or losing the sample will be minimized.
8.7.5 Save a portion of the acetone used for cleanup as a blank.
From each storage container of acetone used for cleanup, save 200 ml and
place in a glass sample container labeled ``acetone blank.'' To minimize
any particulate contamination, rinse the wash bottle prior to filling
from the tested container.
8.7.6 Inspect the train prior to and during disassembly, and note
any abnormal conditions. Treat the samples as follows:
8.7.6.1 Container No. 1. Carefully remove the filter from the filter
holder, and place it in its identified petri dish container. Use a pair
of tweezers and/or clean disposable surgical gloves to handle the
filter. If it is necessary to fold the filter, do so such that the
[[Page 176]]
PM cake is inside the fold. Using a dry Nylon bristle brush and/or a
sharp-edged blade, carefully transfer to the petri dish any PM and/or
filter fibers that adhere to the filter holder gasket. Seal the
container.
8.7.6.2 Container No. 2. Taking care to see that dust on the outside
of the probe or other exterior surfaces does not get into the sample,
quantitatively recover PM or any condensate from the probe nozzle, probe
fitting, probe liner, and front half of the filter holder by washing
these components with acetone and placing the wash in a glass container.
Deionized distilled water may be used instead of acetone when approved
by the Administrator and shall be used when specified by the
Administrator. In these cases, save a water blank, and follow the
Administrator's directions on analysis. Perform the acetone rinse as
follows:
8.7.6.2.1 Carefully remove the probe nozzle. Clean the inside
surface by rinsing with acetone from a wash bottle and brushing with a
Nylon bristle brush. Brush until the acetone rinse shows no visible
particles, after which make a final rinse of the inside surface with
acetone.
8.7.6.2.2 Brush and rinse the inside parts of the fitting with
acetone in a similar way until no visible particles remain.
8.7.6.2.3 Rinse the probe liner with acetone by tilting and rotating
the probe while squirting acetone into its upper end so that all inside
surfaces will be wetted with acetone. Let the acetone drain from the
lower end into the sample container. A funnel (glass or polyethylene)
may be used to aid in transferring liquid washes to the container.
Follow the acetone rinse with a probe brush. Hold the probe in an
inclined position, squirt acetone into the upper end as the probe brush
is being pushed with a twisting action through the probe; hold a sample
container underneath the lower end of the probe, and catch any acetone
and particulate matter that is brushed from the probe. Run the brush
through the probe three times or more until no visible PM is carried out
with the acetone or until none remains in the probe liner on visual
inspection. With stainless steel or other metal probes, run the brush
through in the above prescribed manner at least six times since metal
probes have small crevices in which particulate matter can be entrapped.
Rinse the brush with acetone, and quantitatively collect these washings
in the sample container. After the brushing, make a final acetone rinse
of the probe.
8.7.6.2.4 It is recommended that two people clean the probe to
minimize sample losses. Between sampling runs, keep brushes clean and
protected from contamination.
8.7.6.2.5 Clean the inside of the front half of the filter holder by
rubbing the surfaces with a Nylon bristle brush and rinsing with
acetone. Rinse each surface three times or more if needed to remove
visible particulate. Make a final rinse of the brush and filter holder.
Carefully rinse out the glass cyclone, also (if applicable). After all
acetone washings and particulate matter have been collected in the
sample container, tighten the lid on the sample container so that
acetone will not leak out when it is shipped to the laboratory. Mark the
height of the fluid level to allow determination of whether leakage
occurred during transport. Label the container to clearly identify its
contents.
8.7.6.3 Container No. 3. Note the color of the indicating silica gel
to determine whether it has been completely spent, and make a notation
of its condition. Transfer the silica gel from the fourth impinger to
its original container, and seal. A funnel may make it easier to pour
the silica gel without spilling. A rubber policeman may be used as an
aid in removing the silica gel from the impinger. It is not necessary to
remove the small amount of dust particles that may adhere to the
impinger wall and are difficult to remove. Since the gain in weight is
to be used for moisture calculations, do not use any water or other
liquids to transfer the silica gel. If a balance is available in the
field, follow the procedure for Container No. 3 in section 11.2.3.
8.7.6.4 Impinger Water. Treat the impingers as follows: Make a
notation of any color or film in the liquid catch. Measure the liquid
that is in the first three impingers to within 1 ml by using a graduated
cylinder or by weighing it to within 0.5 g by using a balance. Record
the volume or weight of liquid present. This information is required to
calculate the moisture content of the effluent gas. Discard the liquid
after measuring and recording the volume or weight, unless analysis of
the impinger catch is required (see NOTE, section 6.1.1.8). If a
different type of condenser is used, measure the amount of moisture
condensed either volumetrically or gravimetrically.
8.8 Sample Transport. Whenever possible, containers should be
shipped in such a way that they remain upright at all times.
9.0 Quality Control
9.1 Miscellaneous Quality Control Measures.
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
8.4, 10.1-10.6................ Sampling Ensures accurate
equipment leak measurement of stack
check and gas flow rate,
calibration. sample volume.
------------------------------------------------------------------------
[[Page 177]]
9.2 Volume Metering System Checks. The following procedures are
suggested to check the volume metering system calibration values at the
field test site prior to sample collection. These procedures are
optional.
9.2.1 Meter Orifice Check. Using the calibration data obtained
during the calibration procedure described in section 10.3, determine
the [Delta]H@ for the metering system orifice. The [Delta]H@ is the
orifice pressure differential in units of in. H2O that
correlates to 0.75 cfm of air at 528 [deg]R and 29.92 in. Hg. The
[Delta]H@ is calculated as follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.107
Where:
[Delta]H = Average pressure differential across the orifice meter, in.
H2O.
Tm = Absolute average DGM temperature, [deg]R.
Pbar = Barometric pressure, in. Hg.
[thetas] = Total sampling time, min.
Y = DGM calibration factor, dimensionless.
Vm = Volume of gas sample as measured by DGM, dcf.
0.0319 = (0.0567 in. Hg/[deg]R) (0.75 cfm)\2\
9.2.1.1 Before beginning the field test (a set of three runs usually
constitutes a field test), operate the metering system (i.e., pump,
volume meter, and orifice) at the [Delta]H@ pressure differential for 10
minutes. Record the volume collected, the DGM temperature, and the
barometric pressure. Calculate a DGM calibration check value,
Yc, as follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.108
where:
Yc = DGM calibration check value, dimensionless.
10 = Run time, min.
9.2.1.2 Compare the Yc value with the dry gas meter
calibration factor Y to determine that: 0.97Y c <1.03Y. If
the Yc value is not within this range, the volume metering
system should be investigated before beginning the test.
9.2.2 Calibrated Critical Orifice. A critical orifice, calibrated
against a wet test meter or spirometer and designed to be inserted at
the inlet of the sampling meter box, may be used as a check by following
the procedure of section 16.2.
10.0 Calibration and Standardization
Note: Maintain a laboratory log of all calibrations.
10.1 Probe Nozzle. Probe nozzles shall be calibrated before their
initial use in the field. Using a micrometer, measure the ID of the
nozzle to the nearest 0.025 mm (0.001 in.). Make three separate
measurements using different diameters each time, and obtain the average
of the measurements. The difference between the high and low numbers
shall not exceed 0.1 mm (0.004 in.). When nozzles become nicked, dented,
or corroded, they shall be reshaped, sharpened, and recalibrated before
use. Each nozzle shall be permanently and uniquely identified.
10.2 Pitot Tube Assembly. The Type S pitot tube assembly shall be
calibrated according to the procedure outlined in section 10.1 of Method
2.
10.3 Metering System.
10.3.1 Calibration Prior to Use. Before its initial use in the
field, the metering system shall be calibrated as follows: Connect the
metering system inlet to the outlet of a wet test meter that is accurate
to within 1 percent. Refer to Figure 5-4. The wet test meter should have
a capacity of 30 liters/rev (1 ft\3\/rev). A spirometer of 400 liters
(14 ft\3\) or more capacity, or equivalent, may be used for this
calibration, although a wet test meter is usually more practical. The
wet test meter should be periodically calibrated with a spirometer or a
liquid displacement meter to ensure the accuracy of the wet test meter.
Spirometers or wet test meters of other sizes may be used, provided that
the specified accuracies of the procedure are maintained. Run the
metering system pump for about 15 minutes with the orifice manometer
indicating a median reading as expected in field use to allow the pump
to warm up and to permit the interior surface of the wet test meter to
be thoroughly wetted. Then, at each of a minimum of three orifice
manometer settings, pass an exact quantity of gas through the wet test
meter and note the gas volume indicated by the DGM. Also note the
barometric pressure and the temperatures of the wet test meter, the
inlet of the DGM, and the outlet of the DGM. Select the highest and
lowest orifice settings to bracket the expected field operating range of
the orifice. Use a minimum volume of 0.14 m\3\ (5 ft\3\) at all orifice
settings. Record all the data on a form similar to Figure 5-5 and
calculate Y, the DGM calibration factor, and [Delta]H , the
orifice calibration factor, at each orifice setting as shown on Figure
5-5. Allowable tolerances for individual Y and [Delta]H
values are given in Figure 5-5. Use the average of the Y values in the
calculations in section 12.0.
10.3.1.1 Before calibrating the metering system, it is suggested
that a leak check be conducted. For metering systems having diaphragm
pumps, the normal leak-check procedure will not detect leakages within
the pump. For these cases the following leak-check procedure is
suggested: make a 10-minute calibration run at 0.00057 m\3\/min (0.020
cfm). At the end of the run, take the difference of the measured wet
test meter and DGM volumes. Divide the difference by
[[Page 178]]
10 to get the leak rate. The leak rate should not exceed 0.00057 m\3\/
min (0.020 cfm).
10.3.2 Calibration After Use. After each field use, the calibration
of the metering system shall be checked by performing three calibration
runs at a single, intermediate orifice setting (based on the previous
field test), with the vacuum set at the maximum value reached during the
test series. To adjust the vacuum, insert a valve between the wet test
meter and the inlet of the metering system. Calculate the average value
of the DGM calibration factor. If the value has changed by more than 5
percent, recalibrate the meter over the full range of orifice settings,
as detailed in section 10.3.1.
Note: Alternative procedures (e.g., rechecking the orifice meter
coefficient) may be used, subject to the approval of the Administrator.
10.3.3 Acceptable Variation in Calibration Check. If the DGM
coefficient values obtained before and after a test series differ by
more than 5 percent, the test series shall either be voided, or
calculations for the test series shall be performed using whichever
meter coefficient value (i.e., before or after) gives the lower value of
total sample volume.
10.4 Probe Heater Calibration. Use a heat source to generate air
heated to selected temperatures that approximate those expected to occur
in the sources to be sampled. Pass this air through the probe at a
typical sample flow rate while measuring the probe inlet and outlet
temperatures at various probe heater settings. For each air temperature
generated, construct a graph of probe heating system setting versus
probe outlet temperature. The procedure outlined in APTD-0576 can also
be used. Probes constructed according to APTD-0581 need not be
calibrated if the calibration curves in APTD-0576 are used. Also, probes
with outlet temperature monitoring capabilities do not require
calibration.
Note: The probe heating system shall be calibrated before its
initial use in the field.
10.5 Temperature Sensors. Use the procedure in Section 10.3 of
Method 2 to calibrate in-stack temperature sensors. Dial thermometers,
such as are used for the DGM and condenser outlet, shall be calibrated
against mercury-in-glass thermometers. An alternative mercury-free NIST-
traceable thermometer may be used if the thermometer is, at a minimum,
equivalent in terms of performance or suitably effective for the
specific temperature measurement application. As an alternative, the
following single-point calibration procedure may be used. After each
test run series, check the accuracy (and, hence, the calibration) of
each thermocouple system at ambient temperature, or any other
temperature, within the range specified by the manufacturer, using a
reference thermometer (either ASTM reference thermometer or a
thermometer that has been calibrated against an ASTM reference
thermometer). The temperatures of the thermocouple and reference
thermometers shall agree to within 2 [deg]F.
10.6 Barometer. Calibrate against a mercury barometer or NIST-
traceable barometer prior to the field test. Alternatively, barometric
pressure may be obtained from a weather report that has been adjusted
for the test point (on the stack) elevation.
10.7 Field Balance Calibration Check. Check the calibration of the
balance used to weigh impingers with a weight that is at least 500g or
within 50g of a loaded impinger. The weight must be ASTM E617-13
``Standard Specification for Laboratory Weights and Precision Mass
Standards'' (incorporated by reference--see 40 CFR 60.17) Class 6 (or
better). Daily before use, the field balance must measure the weight
within 0.5g of the certified mass. If the daily
balance calibration check fails, perform corrective measures and repeat
the check before using balance.
10.8 Analytical Balance Calibration. Perform a multipoint
calibration (at least five points spanning the operational range) of the
analytical balance before the first use, and semiannually thereafter.
The calibration of the analytical balance must be conducted using ASTM
E617-13 ``Standard Specification for Laboratory Weights and Precision
Mass Standards'' (incorporated by reference--see 40 CFR 60.17) Class 2
(or better) tolerance weights. Audit the balance each day it is used for
gravimetric measurements by weighing at least one ASTM E617-13 Class 2
tolerance (or better) calibration weight that corresponds to 50 to 150
percent of the weight of one filter or between 1g and 5g. If the scale
cannot reproduce the value of the calibration weight to within 0.5 mg of
the certified mass, perform corrective measures, and conduct the
multipoint calibration before use.
11.0 Analytical Procedure
11.1 Record the data required on a sheet such as the one shown in
Figure 5-6.
11.2 Handle each sample container as follows:
11.2.1 Container No. 1. Leave the contents in the shipping container
or transfer the filter and any loose PM from the sample container to a
tared weighing container. Desiccate for 24 hours in a desiccator
containing anhydrous calcium sulfate. Weigh to a constant weight, and
report the results to the nearest 0.1 mg. For the purposes of this
section, the term ``constant weight'' means a difference of no more than
0.5 mg or 1 percent of total weight less tare weight, whichever is
greater, between two consecutive weighings, with no less than 6 hours of
desiccation time between weighings. Alternatively, the sample may be
oven dried at
[[Page 179]]
104 [deg]C (220 [deg]F) for 2 to 3 hours, cooled in the desiccator, and
weighed to a constant weight, unless otherwise specified by the
Administrator. The sample may be oven dried at 104 [deg]C (220 [deg]F)
for 2 to 3 hours. Once the sample has cooled, weigh the sample, and use
this weight as a final weight.
11.2.2 Container No. 2. Note the level of liquid in the container,
and confirm on the analysis sheet whether leakage occurred during
transport. If a noticeable amount of leakage has occurred, either void
the sample or use methods, subject to the approval of the Administrator,
to correct the final results. Measure the liquid in this container
either volumetrically to 1 ml or gravimetrically
to 0.5 g. Transfer the contents to a tared 250 ml
beaker, and evaporate to dryness at ambient temperature and pressure.
Desiccate for 24 hours, and weigh to a constant weight. Report the
results to the nearest 0.1 mg.
11.2.3 Container No. 3. Weigh the spent silica gel (or silica gel
plus impinger) to the nearest 0.5 g using a balance. This step may be
conducted in the field.
11.2.4 Acetone Blank Container. Measure the acetone in this
container either volumetrically or gravimetrically. Transfer the acetone
to a tared 250 ml beaker, and evaporate to dryness at ambient
temperature and pressure. Desiccate for 24 hours, and weigh to a
constant weight. Report the results to the nearest 0.1 mg.
Note: The contents of Container No. 2 as well as the acetone blank
container may be evaporated at temperatures higher than ambient. If
evaporation is done at an elevated temperature, the temperature must be
below the boiling point of the solvent; also, to prevent ``bumping,''
the evaporation process must be closely supervised, and the contents of
the beaker must be swirled occasionally to maintain an even temperature.
Use extreme care, as acetone is highly flammable and has a low flash
point.
12.0 Data Analysis and Calculations
Carry out calculations, retaining at least one extra significant
figure beyond that of the acquired data. Round off figures after the
final calculation. Other forms of the equations may be used, provided
that they give equivalent results.
12.1 Nomenclature.
An = Cross-sectional area of nozzle, m\2\ (ft\2\).
Bws = Water vapor in the gas stream, proportion by volume.
Ca = Acetone blank residue concentration, mg/mg.
cs = Concentration of particulate matter in stack gas, dry
basis, corrected to standard conditions, g/dscm (gr/dscf).
I = Percent of isokinetic sampling.
L1 = Individual leakage rate observed during the leak-check
conducted prior to the first component change, m\3\/min
(ft\3\/min)
La = Maximum acceptable leakage rate for either a pretest
leak-check or for a leak-check following a component change;
equal to 0.00057 m\3\/min (0.020 cfm) or 4 percent of the
average sampling rate, whichever is less.
Li = Individual leakage rate observed during the leak-check
conducted prior to the ``i\th\'' component change (i = 1, 2, 3
. . . n), m\3\/min (cfm).
Lp = Leakage rate observed during the post-test leak-check,
m\3\/min (cfm).
ma = Mass of residue of acetone after evaporation, mg.
mn = Total amount of particulate matter collected, mg.
Mw = Molecular weight of water, 18.0 g/g-mole (18.0 lb/lb-
mole).
Pbar = Barometric pressure at the sampling site, mm Hg (in.
Hg).
Ps = Absolute stack gas pressure, mm Hg (in. Hg).
Pstd = Standard absolute pressure, 760 mm Hg (29.92 in. Hg).
R = Ideal gas constant, 0.06236 ((mm Hg)(m\3\))/((K)(g-mole)) {21.85
((in. Hg) (ft \3\))/(([deg]R) (lb-mole)){time} .
Tm = Absolute average DGM temperature (see Figure 5-3), K
([deg]R).
Ts = Absolute average stack gas temperature (see Figure 5-3),
K ([deg]R).
Tstd = Standard absolute temperature, 293 K (528 [deg]R).
Va = Volume of acetone blank, ml.
Vaw = Volume of acetone used in wash, ml.
V1c = Total volume of liquid collected in impingers and
silica gel (see Figure 5-6), ml.
Vm = Volume of gas sample as measured by dry gas meter, dcm
(dcf).
Vm(std) = Volume of gas sample measured by the dry gas meter,
corrected to standard conditions, dscm (dscf).
Vw(std) = Volume of water vapor in the gas sample, corrected
to standard conditions, scm (scf).
Vs = Stack gas velocity, calculated by Method 2, Equation 2-
7, using data obtained from Method 5, m/sec (ft/sec).
Wa = Weight of residue in acetone wash, mg.
Y = Dry gas meter calibration factor.
[Delta]H = Average pressure differential across the orifice meter (see
Figure 5-4), mm H2O (in. H2O).
[rho]a = Density of acetone, mg/ml (see label on bottle).
[rho]w = Density of water, 0.9982 g/ml. (0.002201 lb/ml).
[thetas] = Total sampling time, min.
[thetas]1 = Sampling time interval, from the beginning of a
run until the first component change, min.
[thetas]i = Sampling time interval, between two successive
component changes, beginning
[[Page 180]]
with the interval between the first and second changes, min.
[thetas]p = Sampling time interval, from the final (n \th\)
component change until the end of the sampling run, min.
13.6 = Specific gravity of mercury.
60 = Sec/min.
100 = Conversion to percent.
12.2 Average Dry Gas Meter Temperature and Average Orifice Pressure
Drop. See data sheet (Figure 5-3).
12.3 Dry Gas Volume. Correct the sample volume measured by the dry
gas meter to standard conditions (20 [deg]C, 760 mm Hg or 68 [deg]F,
29.92 in. Hg) by using Equation 5-1.
[GRAPHIC] [TIFF OMITTED] TR17OC00.109
Where:
K1 = 0.3858 [deg]K/mm Hg for metric units, = 17.64 [deg]R/in.
Hg for English units.
Note: Equation 5-1 can be used as written unless the leakage rate
observed during any of the mandatory leak checks (i.e., the post-test
leak check or leak checks conducted prior to component changes) exceeds
La. If Lp or Li exceeds La,
Equation 5-1 must be modified as follows:
(a) Case I. No component changes made during sampling run. In this
case, replace Vm in Equation 5-1 with the expression:
[GRAPHIC] [TIFF OMITTED] TR17OC00.110
(b) Case II. One or more component changes made during the sampling
run. In this case, replace Vm in Equation 5-1 by the
expression:
[GRAPHIC] [TIFF OMITTED] TR17OC00.111
and substitute only for those leakage rates (Li or
Lp) which exceed La.
12.4 Volume of Water Vapor Condensed.
[GRAPHIC] [TIFF OMITTED] TR17OC00.112
Where:
K2 = 0.001333 m\3\/ml for metric units, = 0.04706 ft \3\/ml
for English units.
12.5 Moisture Content.
[GRAPHIC] [TIFF OMITTED] TR17OC00.113
Note: In saturated or water droplet-laden gas streams, two
calculations of the moisture content of the stack gas shall be made, one
from the impinger analysis (Equation 5-3), and a second from the
assumption of saturated conditions. The lower of the two values of
Bws shall be considered correct. The procedure for
determining the moisture content based upon the assumption of saturated
conditions is given in section 4.0 of Method 4. For the purposes of this
method, the average stack gas temperature from Figure 5-3 may be used to
make this determination, provided that the accuracy of the in-stack
temperature sensor is 1 [deg]C (2 [deg]F).
12.6 Acetone Blank Concentration.
[GRAPHIC] [TIFF OMITTED] TR17OC00.114
12.7 Acetone Wash Blank.
[[Page 181]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.115
12.8 Total Particulate Weight. Determine the total particulate
matter catch from the sum of the weights obtained from Containers 1 and
2 less the acetone blank (see Figure 5-6).
Note: In no case shall a blank value of greater than 0.001 percent
of the weight of acetone used be subtracted from the sample weight.
Refer to section 8.5.8 to assist in calculation of results involving two
or more filter assemblies or two or more sampling trains.
12.9 Particulate Concentration.
[GRAPHIC] [TIFF OMITTED] TR17OC00.116
Where:
K3 = 0.001 g/mg for metric units.
= 0.0154 gr/mg for English units.
12.10 Conversion Factors:
------------------------------------------------------------------------
From To Multiply by
------------------------------------------------------------------------
ft\3\............................... m\3\ 0.02832
gr.................................. mg 64.80004
gr/ft\3\............................ mg/m\3\ 2288.4
mg.................................. g 0.001
gr.................................. lb 1.429 x 10-4
------------------------------------------------------------------------
12.11 Isokinetic Variation.
12.11.1 Calculation from Raw Data.
[GRAPHIC] [TIFF OMITTED] TR17OC00.117
Where:
K4 = 0.003454 ((mm Hg)(m\3\))/((ml)([deg]K)) for metric
units,
= 0.002669 ((in. Hg)(ft\3\))/((ml)([deg]R)) for English units.
12.11.2 Calculation from Intermediate Values.
[GRAPHIC] [TIFF OMITTED] TR17OC00.118
Where:
K5 = 4.320 for metric units,
= 0.09450 for English units.
12.11.3 Acceptable Results. If 90 percent <=I <=110 percent, the
results are acceptable. If the PM results are low in comparison to the
standard, and ``I'' is over 110 percent or less than 90 percent, the
Administrator may opt to accept the results. Reference 4 in section 17.0
may be used to make acceptability judgments. If ``I'' is judged to be
unacceptable, reject the results, and repeat the sampling run.
12.12 Stack Gas Velocity and Volumetric Flow Rate. Calculate the
average stack gas velocity and volumetric flow rate, if needed, using
data obtained in this method and the equations in sections 12.3 and 12.4
of Method 2.
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Alternative Procedures
16.1 Dry Gas Meter as a Calibration Standard. A DGM may be used as a
calibration standard for volume measurements in place of the wet test
meter specified in section 10.3, provided that it is calibrated
initially and recalibrated periodically as follows:
16.1.1 Standard Dry Gas Meter Calibration.
16.1.1.1. The DGM to be calibrated and used as a secondary reference
meter should be of high quality and have an appropriately sized capacity
(e.g., 3 liters/rev (0.1 ft\3\/rev)). A spirometer (400 liters (14
ft\3\) or more capacity), or equivalent, may be used for this
calibration, although a wet test meter is usually more practical. The
wet test meter should have a capacity of 30 liters/rev (1 ft\3\/rev) and
capable of measuring volume to within 1.0 percent. Wet test meters
should be checked against a spirometer or a liquid displacement meter to
ensure the accuracy of the wet test meter. Spirometers or wet test
meters of other sizes may be used, provided that
[[Page 182]]
the specified accuracies of the procedure are maintained.
16.1.1.2 Set up the components as shown in Figure 5-7. A spirometer,
or equivalent, may be used in place of the wet test meter in the system.
Run the pump for at least 5 minutes at a flow rate of about 10 liters/
min (0.35 cfm) to condition the interior surface of the wet test meter.
The pressure drop indicated by the manometer at the inlet side of the
DGM should be minimized (no greater than 100 mm H2O (4 in.
H2O) at a flow rate of 30 liters/min (1 cfm)). This can be
accomplished by using large diameter tubing connections and straight
pipe fittings.
16.1.1.3 Collect the data as shown in the example data sheet (see
Figure 5-8). Make triplicate runs at each of the flow rates and at no
less than five different flow rates. The range of flow rates should be
between 10 and 34 liters/min (0.35 and 1.2 cfm) or over the expected
operating range.
16.1.1.4 Calculate flow rate, Q, for each run using the wet test
meter volume, VW, and the run time, [thetas]. Calculate the
DGM coefficient, Yds, for each run. These calculations are as
follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.119
[GRAPHIC] [TIFF OMITTED] TR17OC00.120
Where:
K1 = 0.3858 [deg]C/mm Hg for metric units = 17.64 [deg]F/in.
Hg for English units.
VW = Wet test meter volume, liter (ft\3\).
Vds = Dry gas meter volume, liter (ft\3\).
Tds = Average dry gas meter temperature, [deg]C ( [deg]F).
Tadj = 273 [deg]C for metric units = 460 [deg]F for English
units.
TW = Average wet test meter temperature, [deg]C ( [deg]F)
Pbar = Barometric pressure, mm Hg (in. Hg).
[Delta]p = Dry gas meter inlet differential pressure, mm H2O
(in. H2O).
[thetas] = Run time, min.
16.1.1.5 Compare the three Yds values at each of the flow
rates and determine the maximum and minimum values. The difference
between the maximum and minimum values at each flow rate should be no
greater than 0.030. Extra sets of triplicate runs may be made in order
to complete this requirement. In addition, the meter coefficients should
be between 0.95 and 1.05. If these specifications cannot be met in three
sets of successive triplicate runs, the meter is not suitable as a
calibration standard and should not be used as such. If these
specifications are met, average the three Yds values at each
flow rate resulting in no less than five average meter coefficients,
Yds.
16.1.1.6 Prepare a curve of meter coefficient, Yds,
versus flow rate, Q, for the DGM. This curve shall be used as a
reference when the meter is used to calibrate other DGMs and to
determine whether recalibration is required.
16.1.2 Standard Dry Gas Meter Recalibration.
16.1.2.1 Recalibrate the standard DGM against a wet test meter or
spirometer annually or after every 200 hours of operation, whichever
comes first. This requirement is valid provided the standard DGM is kept
in a laboratory and, if transported, cared for as any other laboratory
instrument. Abuse to the standard meter may cause a change in the
calibration and will require more frequent recalibrations.
16.1.2.2 As an alternative to full recalibration, a two-point
calibration check may be made. Follow the same procedure and equipment
arrangement as for a full recalibration, but run the meter at only two
flow rates [suggested rates are 14 and 30 liters/min (0.5 and 1.0 cfm)].
Calculate the meter coefficients for these two points, and compare the
values with the meter calibration curve. If the two coefficients are
within 1.5 percent of the calibration curve values at the same flow
rates, the meter need not be recalibrated until the next date for a
recalibration check.
16.2 Critical Orifices As Calibration Standards. Critical orifices
may be used as calibration standards in place of the wet test meter
specified in section 16.1, provided that they are selected, calibrated,
and used as follows:
16.2.1 Selection of Critical Orifices.
16.2.1.1 The procedure that follows describes the use of hypodermic
needles or stainless steel needle tubings which have been found suitable
for use as critical orifices. Other materials and critical orifice
designs may be used provided the orifices act as true critical orifices
(i.e., a critical vacuum can be obtained, as described in section
16.2.2.2.3). Select five critical orifices that are appropriately sized
to cover the range of
[[Page 183]]
flow rates between 10 and 34 liters/min (0.35 and 1.2 cfm) or the
expected operating range. Two of the critical orifices should bracket
the expected operating range. A minimum of three critical orifices will
be needed to calibrate a Method 5 DGM; the other two critical orifices
can serve as spares and provide better selection for bracketing the
range of operating flow rates. The needle sizes and tubing lengths shown
in Table 5-1 in section 18.0 give the approximate flow rates.
16.2.1.2 These needles can be adapted to a Method 5 type sampling
train as follows: Insert a serum bottle stopper, 13 by 20 mm sleeve
type, into a \1/2\-inch Swagelok (or equivalent) quick connect. Insert
the needle into the stopper as shown in Figure 5-9.
16.2.2 Critical Orifice Calibration. The procedure described in this
section uses the Method 5 meter box configuration with a DGM as
described in section 6.1.1.9 to calibrate the critical orifices. Other
schemes may be used, subject to the approval of the Administrator.
16.2.2.1 Calibration of Meter Box. The critical orifices must be
calibrated in the same configuration as they will be used (i.e., there
should be no connections to the inlet of the orifice).
16.2.2.1.1 Before calibrating the meter box, leak check the system
as follows: Fully open the coarse adjust valve, and completely close the
by-pass valve. Plug the inlet. Then turn on the pump, and determine
whether there is any leakage. The leakage rate shall be zero (i.e., no
detectable movement of the DGM dial shall be seen for 1 minute).
16.2.2.1.2 Check also for leakages in that portion of the sampling
train between the pump and the orifice meter. See section 8.4.1 for the
procedure; make any corrections, if necessary. If leakage is detected,
check for cracked gaskets, loose fittings, worn O-rings, etc., and make
the necessary repairs.
16.2.2.1.3 After determining that the meter box is leakless,
calibrate the meter box according to the procedure given in section
10.3. Make sure that the wet test meter meets the requirements stated in
section 16.1.1.1. Check the water level in the wet test meter. Record
the DGM calibration factor, Y.
16.2.2.2 Calibration of Critical Orifices. Set up the apparatus as
shown in Figure 5-10.
16.2.2.2.1 Allow a warm-up time of 15 minutes. This step is
important to equilibrate the temperature conditions through the DGM.
16.2.2.2.2 Leak check the system as in section 16.2.2.1.1. The
leakage rate shall be zero.
16.2.2.2.3 Before calibrating the critical orifice, determine its
suitability and the appropriate operating vacuum as follows: Turn on the
pump, fully open the coarse adjust valve, and adjust the by-pass valve
to give a vacuum reading corresponding to about half of atmospheric
pressure. Observe the meter box orifice manometer reading, [Delta]H.
Slowly increase the vacuum reading until a stable reading is obtained on
the meter box orifice manometer. Record the critical vacuum for each
orifice. Orifices that do not reach a critical value shall not be used.
16.2.2.2.4 Obtain the barometric pressure using a barometer as
described in section 6.1.2. Record the barometric pressure,
Pbar, in mm Hg (in. Hg).
16.2.2.2.5 Conduct duplicate runs at a vacuum of 25 to 50 mm Hg (1
to 2 in. Hg) above the critical vacuum. The runs shall be at least 5
minutes each. The DGM volume readings shall be in increments of complete
revolutions of the DGM. As a guideline, the times should not differ by
more than 3.0 seconds (this includes allowance for changes in the DGM
temperatures) to achieve 0.5 percent in K' (see
Eq. 5-11). Record the information listed in Figure 5-11.
16.2.2.2.6 Calculate K' using Equation 5-11.
[GRAPHIC] [TIFF OMITTED] TR17OC00.121
Where:
K' = Critical orifice coefficient,
[m\3\)([deg]K)\1/2\]/
[(mm Hg)(min)] {[(ft \3\)([deg]R)\1/2\)] [(in. Hg)(min)].
Tamb = Absolute ambient temperature, [deg]K ([deg]R).
Calculate the arithmetic mean of the K' values. The individual K'
values should not differ by more than 0.5 percent
from the mean value.
16.2.3 Using the Critical Orifices as Calibration Standards.
16.2.3.1 Record the barometric pressure.
16.2.3.2 Calibrate the metering system according to the procedure
outlined in section 16.2.2. Record the information listed in Figure 5-
12.
16.2.3.3 Calculate the standard volumes of air passed through the
DGM and the critical orifices, and calculate the DGM calibration factor,
Y, using the equations below:
[[Page 184]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.122
[GRAPHIC] [TIFF OMITTED] TR27FE14.012
[GRAPHIC] [TIFF OMITTED] TR17OC00.124
Where:
Vcr(std) = Volume of gas sample passed through the critical
orifice, corrected to standard conditions, dscm (dscf).
K1 = 0.3858 K/mm Hg for metric units
= 17.64 [deg]R/in. Hg for English units.
16.2.3.4 Average the DGM calibration values for each of the flow
rates. The calibration factor, Y, at each of the flow rates should not
differ by more than 2 percent from the average.
16.2.3.5 To determine the need for recalibrating the critical
orifices, compare the DGM Y factors obtained from two adjacent orifices
each time a DGM is calibrated; for example, when checking orifice 13/
2.5, use orifices 12/10.2 and 13/5.1. If any critical orifice yields a
DGM Y factor differing by more than 2 percent from the others,
recalibrate the critical orifice according to section 16.2.2.
16.3 Alternative Post-Test Metering System Calibration. The
following procedure may be used as an alternative to the post-test
calibration described in Section 10.3.2. This alternative procedure does
not detect leakages between the inlet of the metering system and the dry
gas meter. Therefore, two steps must be included to make it an
equivalent alternative:
(1) The metering system must pass the post-test leak-check from
either the inlet of the sampling train or the inlet of the metering
system. Therefore, if the train fails the former leak-check, another
leak-check from the inlet of the metering system must be conducted;
(2) The metering system must pass the leak-check of that portion of
the train from the pump to the orifice meter as described in Section
8.4.1.
16.3.1 After each test run, do the following:
16.3.1.1 Ensure that the metering system has passed the post-test
leak-check. If not, conduct a leak-check of the metering system from its
inlet.
16.3.1.2 Conduct the leak-check of that portion of the train from
the pump to the orifice meter as described in Section 10.3.1.1.
16.3.1.3 Calculate Yqa for each test run using the
following equation:
[GRAPHIC] [TIFF OMITTED] TR27FE14.013
Where:
Yqa = Dry gas meter calibration check value, dimensionless.
0.0319 = (29.92/528) (0.75) \2\ (in. Hg/[deg]R) cfm\2\.
[Delta]H@ = Orifice meter calibration coefficient, in. H2O.
Md = Dry molecular weight of stack gas, lb/lb-mole.
29 = Dry molecular weight of air, lb/lb-mole.
16.3.2 After each test run series, do the following:
16.3.2.1 Average the three or more Yqa's obtained from
the test run series and compare this average Yqa with the dry
gas meter calibration factor Y. The average Yqa must be
within 5 percent of Y.
16.3.2.2 If the average Yqa does not meet the 5 percent
criterion, recalibrate the meter
[[Page 185]]
over the full range of orifice settings as detailed in Section 10.3.1.
Then follow the procedure in Section 10.3.3.
17.0 References.
1. Addendum to Specifications for Incinerator Testing at Federal
Facilities. PHS, NCAPC. December 6, 1967.
2. Martin, Robert M. Construction Details of Isokinetic Source-
Sampling Equipment. Environmental Protection Agency. Research Triangle
Park, NC. APTD-0581. April 1971.
3. Rom, Jerome J. Maintenance, Calibration, and Operation of
Isokinetic Source Sampling Equipment. Environmental Protection Agency.
Research Triangle Park, NC. APTD-0576. March 1972.
4. Smith, W.S., R.T. Shigehara, and W.F. Todd. A Method of
Interpreting Stack Sampling Data. Paper Presented at the 63rd Annual
Meeting of the Air Pollution Control Association, St. Louis, MO. June
14-19, 1970.
5. Smith, W.S., et al. Stack Gas Sampling Improved and Simplified
With New Equipment. APCA Paper No. 67-119. 1967.
6. Specifications for Incinerator Testing at Federal Facilities.
PHS, NCAPC. 1967.
7. Shigehara, R.T. Adjustment in the EPA Nomograph for Different
Pitot Tube Coefficients and Dry Molecular Weights. Stack Sampling News
2:4-11. October 1974.
8. Vollaro, R.F. A Survey of Commercially Available Instrumentation
for the Measurement of Low-Range Gas Velocities. U.S. Environmental
Protection Agency, Emission Measurement Branch. Research Triangle Park,
NC. November 1976 (unpublished paper).
9. Annual Book of ASTM Standards. Part 26. Gaseous Fuels; Coal and
Coke; Atmospheric Analysis. American Society for Testing and Materials.
Philadelphia, PA. 1974. pp. 617-622.
10. Felix, L.G., G.I. Clinard, G.E. Lacy, and J.D. McCain. Inertial
Cascade Impactor Substrate Media for Flue Gas Sampling. U.S.
Environmental Protection Agency. Research Triangle Park, NC 27711.
Publication No. EPA-600/7-77-060. June 1977. 83 pp.
11. Westlin, P.R. and R.T. Shigehara. Procedure for Calibrating and
Using Dry Gas Volume Meters as Calibration Standards. Source Evaluation
Society Newsletter. 3(1):17-30. February 1978.
12. Lodge, J.P., Jr., J.B. Pate, B.E. Ammons, and G.A. Swanson. The
Use of Hypodermic Needles as Critical Orifices in Air Sampling. J. Air
Pollution Control Association. 16:197-200. 1966.
13. Shigehara, Roger T., P.G. Royals, and E.W. Steward.
``Alternative Method 5 Post-Test Calibration.'' Entropy Incorporated,
Research Triangle Park, NC 27709.
18.0 Tables, Diagrams, Flowcharts, and Validation Data
Table 5-1 Flor Rates for Various needle Sizes and Tube Lengths
----------------------------------------------------------------------------------------------------------------
Flow rate Flow rate
Gauge/cm liters/min. Gauge/cm liters/min.
----------------------------------------------------------------------------------------------------------------
12/7.6.......................................................... 32.56 14/2.5 19.54
12/10.2......................................................... 30.02 14/5.1 17.27
13/2.5.......................................................... 25.77 14/7.6 16.14
13/5.1.......................................................... 23.50 15/3.2 14.16
13/7.6.......................................................... 22.37 15/7.6 11.61
13/10.2......................................................... 20.67 15/10.2 10.48
----------------------------------------------------------------------------------------------------------------
[[Page 186]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.125
[[Page 187]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.126
[[Page 188]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.127
[[Page 189]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.128
[[Page 190]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.129
Plant___________________________________________________________________
Date____________________________________________________________________
Run No._________________________________________________________________
Filter No.______________________________________________________________
Amount liquid lost during transport_____________________________________
Acetone blank volume, m1________________________________________________
Acetone blank concentration, mg/mg (Equation 5-4)_______________________
Acetone wash blank, mg (Equation 5-5)
[[Page 191]]
________________________________________________________________________
----------------------------------------------------------------------------------------------------------------
Weight of particulate collected, mg
Container number --------------------------------------------------------------------------
Final weight Tare weight Weight gain
----------------------------------------------------------------------------------------------------------------
1.
----------------------------------------------------------------------------------------------------------------
2.
----------------------------------------------------------------------------------------------------------------
Total:
Less acetone blank...........
Weight of particulate matter.
----------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------
Volume of liquid water collected
---------------------------------------
Impinger volume, Silica gel weight,
ml g
------------------------------------------------------------------------
Final
Initial
Liquid collected
Total volume collected.... .................. g* ml
------------------------------------------------------------------------
* Convert weight of water to volume by dividing total weight increase by
density of water (1 g/ml).
Figure 5-6. Analytical Data Sheet
[GRAPHIC] [TIFF OMITTED] TR17OC00.147
[[Page 192]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.130
[[Page 193]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.131
[[Page 194]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.132
[[Page 195]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.133
Date____________________________________________________________________
Train ID________________________________________________________________
DGM cal. factor_________________________________________________________
Critical orifice ID_____________________________________________________
------------------------------------------------------------------------
Run No.
Dry gas meter -------------------------
1 2
------------------------------------------------------------------------
Final reading................ m\3\ (ft\3\)... ........... ...........
Initial reading.............. m\3\ (ft\3\)... ........... ...........
Difference, V\m\............. m\3\ (ft\3\)... ........... ...........
Inlet/Outlet................. ............... ........... ...........
[[Page 196]]
Temperatures:............ [deg]C ( / /
[deg]F).
Initial.................. [deg]C ( / /
[deg]F).
Final.................... min/sec........ / /
Av. Temeperature, t m.... min............ ........... ...........
Time, [thetas]............... ............... ........... ...........
Orifice man. rdg., [Delta]H.. mm (in.) H 2... ........... ...........
Bar. pressure, P \bar\....... mm (in.) Hg.... ........... ...........
Ambient temperature, tamb.... mm (in.) Hg.... ........... ...........
Pump vacuum.................. ............... ........... ...........
K' factor.................... ............... ........... ...........
Average.................. ............... ........... ...........
------------------------------------------------------------------------
Figure 5-11. Data sheet of determining K' factor.
Date____________________________________________________________________
Train ID________________________________________________________________
Critical orifice ID_____________________________________________________
Critical orifice K' factor______________________________________________
------------------------------------------------------------------------
Run No.
Dry gas meter -------------------------
1 2
------------------------------------------------------------------------
Final reading................ m\3\ (ft\3\)... ........... ...........
Initial reading.............. m\3\ (ft\3\)... ........... ...........
Difference, Vm............... m\3\ (ft\3\)... ........... ...........
Inlet/outlet temperatures.... [deg]C ( / /
[deg]F).
Initial.................. [deg]C ( / /
[deg]F).
Final.................... [deg]C ( ........... ...........
[deg]F).
Avg. Temperature, tm..... min/sec........ / /
Time, [thetas]............... min............ ........... ...........
Orifice man. rdg., [Delta]H.. min............ ........... ...........
Bar. pressure, Pbar.......... mm (in.) H2O... ........... ...........
Ambient temperature, tamb.... mm (in.) Hg.... ........... ...........
Pump vacuum.................. [deg]C ( ........... ...........
[deg]F).
Vm(std)...................... mm (in.) Hg.... ........... ...........
Vcr(std)..................... m\3\ (ft\3\)... ........... ...........
DGM cal. factor, Y........... m\3\ (ft\3\)... ........... ...........
------------------------------------------------------------------------
Figure 5-12. Data Sheet for Determining DGM Y Factor
Method 5A--Determination of Particulate Matter Emissions From the
Asphalt Processing and Asphalt Roofing Industry
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 2, Method 3, and
Method 5.
1.0 Scope and Applications
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the determination
of PM emissions from asphalt roofing industry process saturators,
blowing stills, and other sources as specified in the regulations.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
Particulate matter is withdrawn isokinetically from the source and
collected on a glass fiber filter maintained at a temperature of 42
10 [deg]C (108 18 [deg]F).
The PM mass, which includes any material that condenses at or above the
filtration temperature, is determined gravimetrically after the removal
of uncombined water.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and to determine the
[[Page 197]]
applicability of regulatory limitations prior to performing this test
method.
6.0 Equipment and Supplies
6.1 Sample Collection. Same as Method 5, section 6.1, with the
following exceptions and additions:
6.1.1 Probe Liner. Same as Method 5, section 6.1.1.2, with the note
that at high stack gas temperatures greater than 250 [deg]C (480
[deg]F), water-cooled probes may be required to control the probe exit
temperature to 42 10 [deg]C (108 18 [deg]F).
6.1.2 Precollector Cyclone. Borosilicate glass following the
construction details shown in Air Pollution Technical Document (APTD)-
0581, ``Construction Details of Isokinetic Source-Sampling Equipment''
(Reference 2 in Method 5, section 17.0).
Note: The cyclone shall be used when the stack gas moisture is
greater than 10 percent, and shall not be used otherwise.
6.1.3 Filter Heating System. Any heating (or cooling) system capable
of maintaining a sample gas temperature at the exit end of the filter
holder during sampling at 42 10 [deg]C (108 18 [deg]F).
6.2 Sample Recovery. The following items are required for sample
recovery:
6.2.1 Probe-Liner and Probe-Nozzle Brushes, Graduated Cylinder and/
or Balance, Plastic Storage Containers, and Funnel and Rubber Policeman.
Same as in Method 5, sections 6.2.1, 6.2.5, 6.2.6, and 6.2.7,
respectively.
6.2.2 Wash Bottles. Glass.
6.2.3 Sample Storage Containers. Chemically resistant 500-ml or
1,000-ml borosilicate glass bottles, with rubber-backed Teflon screw cap
liners or caps that are constructed so as to be leak-free, and resistant
to chemical attack by 1,1,1-trichloroethane (TCE). (Narrow-mouth glass
bottles have been found to be less prone to leakage.)
6.2.4 Petri Dishes. Glass, unless otherwise specified by the
Administrator.
6.2.5 Funnel. Glass.
6.3 Sample Analysis. Same as Method 5, section 6.3, with the
following additions:
6.3.1 Beakers. Glass, 250-ml and 500-ml.
6.3.2 Separatory Funnel. 100-ml or greater.
7.0. Reagents and Standards
7.1 Sample Collection. The following reagents are required for
sample collection:
7.1.1 Filters, Silica Gel, Water, and Crushed Ice. Same as in Method
5, sections 7.1.1, 7.1.2, 7.1.3, and 7.1.4, respectively.
7.1.2 Stopcock Grease. TCE-insoluble, heat-stable grease (if
needed). This is not necessary if screw-on connectors with Teflon
sleeves, or similar, are used.
7.2 Sample Recovery. Reagent grade TCE, <=0.001 percent residue and
stored in glass bottles. Run TCE blanks before field use, and use only
TCE with low blank values (<=0.001 percent). In no case shall a blank
value of greater than 0.001 percent of the weight of TCE used be
subtracted from the sample weight.
7.3 Analysis. Two reagents are required for the analysis:
7.3.1 TCE. Same as in section 7.2.
7.3.2 Desiccant. Same as in Method 5, section 7.3.2.
8.0. Sample Collection, Preservation, Storage, and Transport
8.1 Pretest Preparation. Unless otherwise specified, maintain and
calibrate all components according to the procedure described in APTD-
0576, ``Maintenance, Calibration, and Operation of Isokinetic Source-
Sampling Equipment'' (Reference 3 in Method 5, Section 17.0).
Alternative mercury-free thermometers may be used if the thermometers
are, at a minimum, equivalent in terms of performance or suitably
effective for the specific temperature measurement application.
8.1.1 Prepare probe liners and sampling nozzles as needed for use.
Thoroughly clean each component with soap and water followed by a
minimum of three TCE rinses. Use the probe and nozzle brushes during at
least one of the TCE rinses (refer to section 8.7 for rinsing
techniques). Cap or seal the open ends of the probe liners and nozzles
to prevent contamination during shipping.
8.1.2 Prepare silica gel portions and glass filters as specified in
Method 5, section 8.1.
8.2 Preliminary Determinations. Select the sampling site, probe
nozzle, and probe length as specified in Method 5, section 8.2. Select a
total sampling time greater than or equal to the minimum total sampling
time specified in the ``Test Methods and Procedures'' section of the
applicable subpart of the regulations. Follow the guidelines outlined in
Method 5, section 8.2 for sampling time per point and total sample
volume collected.
8.3 Preparation of Sampling Train. Prepare the sampling train as
specified in Method 5, section 8.3, with the addition of the
precollector cyclone, if used, between the probe and filter holder. The
temperature of the precollector cyclone, if used, should be maintained
in the same range as that of the filter, i.e., 42 10 [deg]C (108 18 [deg]F). Use no
stopcock grease on ground glass joints unless grease is insoluble in
TCE.
8.4 Leak-Check Procedures. Same as Method 5, section 8.4.
8.5 Sampling Train Operation. Operate the sampling train as
described in Method 5, section 8.5, except maintain the temperature of
the gas exiting the filter holder at 42 10 [deg]C
(108 18 [deg]F).
8.6 Calculation of Percent Isokinetic. Same as Method 5, section
8.6.
8.7 Sample Recovery. Same as Method 5, section 8.7.1 through
8.7.6.1, with the addition of the following:
8.7.1 Container No. 2 (Probe to Filter Holder).
[[Page 198]]
8.7.1.1 Taking care to see that material on the outside of the probe
or other exterior surfaces does not get into the sample, quantitatively
recover PM or any condensate from the probe nozzle, probe fitting, probe
liner, precollector cyclone and collector flask (if used), and front
half of the filter holder by washing these components with TCE and
placing the wash in a glass container. Carefully measure the total
amount of TCE used in the rinses. Perform the TCE rinses as described in
Method 5, section 8.7.6.2, using TCE instead of acetone.
8.7.1.2 Brush and rinse the inside of the cyclone, cyclone
collection flask, and the front half of the filter holder. Brush and
rinse each surface three times or more, if necessary, to remove visible
PM.
8.7.2 Container No. 3 (Silica Gel). Same as in Method 5, section
8.7.6.3.
8.7.3 Impinger Water. Same as Method 5, section 8.7.6.4.
8.8 Blank. Save a portion of the TCE used for cleanup as a blank.
Take 200 ml of this TCE directly from the wash bottle being used, and
place it in a glass sample container labeled ``TCE Blank.''
9.0 Quality Control
9.1 Miscellaneous Quality Control Measures.
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
8.4, 10.0..................... Sampling Ensures accurate
equipment leak measurement of stack
check and gas flow rate,
calibration. sample volume.
------------------------------------------------------------------------
9.2 A quality control (QC) check of the volume metering system at
the field site is suggested before collecting the sample. Use the
procedure outlined in Method 5, section 9.2.
10.0 Calibration and Standardization
Same as Method 5, section 10.0.
11.0 Analytical Procedures
11.1 Analysis. Record the data required on a sheet such as the one
shown in Figure 5A-1. Handle each sample container as follows:
11.1.1 Container No. 1 (Filter). Transfer the filter from the sample
container to a tared glass weighing dish, and desiccate for 24 hours in
a desiccator containing anhydrous calcium sulfate. Rinse Container No. 1
with a measured amount of TCE, and analyze this rinse with the contents
of Container No. 2. Weigh the filter to a constant weight. For the
purpose of this analysis, the term ``constant weight'' means a
difference of no more than 10 percent of the net filter weight or 2 mg
(whichever is greater) between two consecutive weighings made 24 hours
apart. Report the ``final weight'' to the nearest 0.1 mg as the average
of these two values.
11.1.2 Container No. 2 (Probe to Filter Holder).
11.1.2.1 Before adding the rinse from Container No. 1 to Container
No. 2, note the level of liquid in Container No. 2, and confirm on the
analysis sheet whether leakage occurred during transport. If noticeable
leakage occurred, either void the sample or take steps, subject to the
approval of the Administrator, to correct the final results.
11.1.2.2 Add the rinse from Container No. 1 to Container No. 2 and
measure the liquid in this container either volumetrically to 1 ml or gravimetrically to 0.5 g.
Check to see whether there is any appreciable quantity of condensed
water present in the TCE rinse (look for a boundary layer or phase
separation). If the volume of condensed water appears larger than 5 ml,
separate the oil-TCE fraction from the water fraction using a separatory
funnel. Measure the volume of the water phase to the nearest ml; adjust
the stack gas moisture content, if necessary (see sections 12.3 and
12.4). Next, extract the water phase with several 25-ml portions of TCE
until, by visual observation, the TCE does not remove any additional
organic material. Transfer the remaining water fraction to a tared
beaker and evaporate to dryness at 93 [deg]C (200 [deg]F), desiccate for
24 hours, and weigh to the nearest 0.1 mg.
11.1.2.3 Treat the total TCE fraction (including TCE from the filter
container rinse and water phase extractions) as follows: Transfer the
TCE and oil to a tared beaker, and evaporate at ambient temperature and
pressure. The evaporation of TCE from the solution may take several
days. Do not desiccate the sample until the solution reaches an apparent
constant volume or until the odor of TCE is not detected. When it
appears that the TCE has evaporated, desiccate the sample, and weigh it
at 24-hour intervals to obtain a ``constant weight'' (as defined for
Container No. 1 above). The ``total weight'' for Container No. 2 is the
sum of the evaporated PM weight of the TCE-oil and water phase
fractions. Report the results to the nearest 0.1 mg.
11.1.3 Container No. 3 (Silica Gel). This step may be conducted in
the field. Weigh the spent silica gel (or silica gel plus impinger) to
the nearest 0.5 g using a balance.
11.1.4 ``TCE Blank'' Container. Measure TCE in this container either
volumetrically or gravimetrically. Transfer the TCE to a tared 250-ml
beaker, and evaporate to dryness at ambient temperature and pressure.
[[Page 199]]
Desiccate for 24 hours, and weigh to a constant weight. Report the
results to the nearest 0.1 mg.
Note: In order to facilitate the evaporation of TCE liquid samples,
these samples may be dried in a controlled temperature oven at
temperatures up to 38 [deg]C (100 [deg]F) until the liquid is
evaporated.
12.0 Data Analysis and Calculations
Carry out calculations, retaining at least one extra significant
figure beyond that of the acquired data. Round off figures after the
final calculation. Other forms of the equations may be used as long as
they give equivalent results.
12.1 Nomenclature. Same as Method 5, section 12.1, with the
following additions:
Ct = TCE blank residue concentration, mg/g.
mt = Mass of residue of TCE blank after evaporation, mg.
Vpc = Volume of water collected in precollector, ml.
Vt = Volume of TCE blank, ml.
Vtw = Volume of TCE used in wash, ml.
Wt = Weight of residue in TCE wash, mg.
[rho]t = Density of TCE (see label on bottle), g/ml.
12.2 Dry Gas Meter Temperature, Orifice Pressure Drop, and Dry Gas
Volume. Same as Method 5, sections 12.2 and 12.3, except use data
obtained in performing this test.
12.3 Volume of Water Vapor.
[GRAPHIC] [TIFF OMITTED] TR17OC00.134
Where:
K2 = 0.001333 m\3\/ml for metric units.
= 0.04706 ft\3\/ml for English units.
12.4 Moisture Content.
[GRAPHIC] [TIFF OMITTED] TR17OC00.135
Note: In saturated or water droplet-laden gas streams, two
calculations of the moisture content of the stack gas shall be made, one
from the impinger and precollector analysis (Equations 5A-1 and 5A-2)
and a second from the assumption of saturated conditions. The lower of
the two values of moisture content shall be considered correct. The
procedure for determining the moisture content based upon assumption of
saturated conditions is given in section 4.0 of Method 4. For the
purpose of this method, the average stack gas temperature from Figure 5-
3 of Method 5 may be used to make this determination, provided that the
accuracy of the in-stack temperature sensor is within 1 [deg]C (2
[deg]F).
12.5 TCE Blank Concentration.
[GRAPHIC] [TIFF OMITTED] TR17OC00.136
Note: In no case shall a blank value of greater than 0.001 percent
of the weight of TCE used be subtracted from the sample weight.
12.6 TCE Wash Blank.
[GRAPHIC] [TIFF OMITTED] TR17OC00.137
12.7 Total PM Weight. Determine the total PM catch from the sum of
the weights obtained from Containers 1 and 2, less the TCE blank.
12.8 PM Concentration.
[GRAPHIC] [TIFF OMITTED] TR17OC00.138
Where:
K3 = 0.001 g/mg for metric units
= 0.0154 gr/mg for English units
12.9 Isokinetic Variation. Same as in Method 5, section 12.11.
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
Same as Method 5, section 17.0.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
Plant___________________________________________________________________
Date____________________________________________________________________
Run No._________________________________________________________________
Filter No.______________________________________________________________
Amount liquid lost during transport_____________________________________
Acetone blank volume, m1________________________________________________
Acetone blank concentration, mg/mg (Equation 5-4)_______________________
Acetone wash blank, mg (Equation 5-5)___________________________________
----------------------------------------------------------------------------------------------------------------
Weight of particulate collected, mg
Container number --------------------------------------------------------------------------
Final weight Tare weight Weight gain
----------------------------------------------------------------------------------------------------------------
1.
----------------------------------------------------------------------------------------------------------------
2.
----------------------------------------------------------------------------------------------------------------
Total:
Less acetone blank...........
[[Page 200]]
Weight of particulate matter.
----------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------
Volume of liquid water collected
---------------------------------------
Impinger volume, Silica gel weight,
ml g
------------------------------------------------------------------------
Final
Initial
Liquid collected
Total volume collected.... .................. g* ml
------------------------------------------------------------------------
* Convert weight of water to volume by dividing total weight increase by
density of water (1 g/ml).
[GRAPHIC] [TIFF OMITTED] TR17OC00.139
Method 5B--Determination of Nonsulfuric Acid Particulate Matter
Emissions From Stationary Sources
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 2, Method 3,
Method 5.
1.0 Scope and Application
1.1 Analyte. Nonsulfuric acid particulate matter. No CAS number
assigned.
1.2 Applicability. This method is determining applicable for the
determination of nonsulfuric acid particulate matter from stationary
sources, only where specified by an applicable subpart of the
regulations or where approved by the Administrator for a particular
application.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
Particulate matter is withdrawn isokinetically from the source and
collected on a glass fiber filter maintained at a temperature of 160
14 [deg]C (320 25 [deg]F).
The collected sample is then heated in an oven at 160 [deg]C (320
[deg]F) for 6 hours to volatilize any condensed sulfuric acid that may
have been collected, and the nonsulfuric acid particulate mass is
determined gravimetrically.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and to determine the applicability of regulatory limitations
prior to performing this test method.
6.0 Equipment and Supplies
Same as Method 5, section 6.0, with the following addition and
exceptions:
6.1 Sample Collection. The probe liner heating system and filter
heating system must be capable of maintaining a sample gas temperature
of 160 14 [deg]C (320 25
[deg]F).
6.2 Sample Preparation. An oven is required for drying the sample.
7.0 Reagents and Standards
Same as Method 5, section 7.0.
8.0 Sample Collection, Preservation, Storage, and Transport.
Same as Method 5, with the exception of the following:
8.1 Initial Filter Tare. Oven dry the filter at 160 5 [deg]C (320 10 [deg]F) for 2 to
3 hours, cool in a desiccator for 2 hours, and weigh. Desiccate to
constant weight to obtain the initial tare weight. Use the applicable
specifications and techniques of section 8.1.3 of Method 5 for this
determination.
8.2 Probe and Filter Temperatures. Maintain the probe outlet and
filter temperatures at 160 14 [deg]C (320 25 [deg]F).
9.0 Quality Control
Same as Method 5, section 9.0.
10.0 Calibration and Standardization
Same as Method 5, section 10.0.
[[Page 201]]
11.0 Analytical Procedure
11.1 Record and report the data required on a sheet such as the one
shown in Figure 5B-1.
11.2 Handle each sample container as follows:
11.2.1 Container No. 1. Leave the contents in the shipping container
or transfer the filter and any loose PM from the sample container to a
tared non-reactive oven-proof container. Oven dry the filter sample at a
temperature of 160 5 [deg]C (320 9 [deg]F) for 6 hours. Cool in a desiccator for 2 hours,
and weigh to constant weight. Report the results to the nearest 0.1 mg.
For the purposes of this section, the term ``constant weight'' means a
difference of no more than 0.5 mg or 1 percent of total weight less tare
weight, whichever is greater, between two consecutive weighings, with no
less than 6 hours of desiccation time between weighings.
11.2.2 Container No. 2. Note the level of liquid in the container,
and confirm on the analysis sheet whether leakage occurred during
transport. If a noticeable amount of leakage has occurred, either void
the sample or use methods, subject to the approval of the Administrator,
to correct the final results. Measure the liquid in this container
either volumetrically to 1 ml or gravimetrically
to 0.5 g. Transfer the contents to a tared 250 ml
beaker, and evaporate to dryness at ambient temperature and pressure.
Then oven dry the probe sample at a temperature of 160 5 [deg]C (320 9 [deg]F) for 6
hours. Cool in a desiccator for 2 hours, and weigh to constant weight.
Report the results to the nearest 0.1 mg.
11.2.3 Container No. 3. Weigh the spent silica gel (or silica gel
plus impinger) to the nearest 0.5 g using a balance. This step may be
conducted in the field.
11.2.4 Acetone Blank Container. Measure the acetone in this
container either volumetrically or gravimetrically. Transfer the acetone
to a tared 250 ml beaker, and evaporate to dryness at ambient
temperature and pressure. Desiccate for 24 hours, and weigh to a
constant weight. Report the results to the nearest 0.1 mg.
Note: The contents of Container No. 2 as well as the acetone blank
container may be evaporated at temperatures higher than ambient. If
evaporation is done at an elevated temperature, the temperature must be
below the boiling point of the solvent; also, to prevent ``bumping,''
the evaporation process must be closely supervised, and the contents of
the beaker must be swirled occasionally to maintain an even temperature.
Use extreme care, as acetone is highly flammable and has a low flash
point.
12.0 Data Analysis and Calculations
Same as in Method 5, section 12.0.
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
Same as Method 5, section 17.0.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
------------------------------------------------------------------------
Weight of particulate collected, mg
Container number -----------------------------------------------
Final weight Tare weight Weight gain
------------------------------------------------------------------------
1.
2.
-----------------------------------------------
Total:
-----------------------------------------------
Less acetone blank
Weight of particulate
matter
------------------------------------------------------------------------
Volume of liquid water collected
-------------------------------------------------------------------
Impinger volume, Silica gel weight,
----------------------------------------------------------------------------------------------------------------
ml g
-------------------------------------------------------------------
Final
Initial
Liquid collected
Total volume collected g* ml
* Convert weight of water to volume by dividing total weight increase by density of water (1 g/ml).
[[Page 202]]
Figure 5B-1. Analytical Data Sheet
Method 5C [Reserved]
Method 5D--Determination of Particulate Matter Emissions from Positive
Pressure Fabric Filters
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 2, Method 3,
Method 5, Method 17.
1.0 Scope and Application
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability.
1.2.1 This method is applicable for the determination of PM
emissions from positive pressure fabric filters. Emissions are
determined in terms of concentration (mg/m\3\ or gr/ft\3\) and emission
rate (kg/hr or lb/hr).
1.2.2 The General Provisions of 40 CFR part 60, Sec. 60.8(e),
require that the owner or operator of an affected facility shall provide
performance testing facilities. Such performance testing facilities
include sampling ports, safe sampling platforms, safe access to sampling
sites, and utilities for testing. It is intended that affected
facilities also provide sampling locations that meet the specification
for adequate stack length and minimal flow disturbances as described in
Method 1. Provisions for testing are often overlooked factors in
designing fabric filters or are extremely costly. The purpose of this
procedure is to identify appropriate alternative locations and
procedures for sampling the emissions from positive pressure fabric
filters. The requirements that the affected facility owner or operator
provide adequate access to performance testing facilities remain in
effect.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 Particulate matter is withdrawn isokinetically from the source
and collected on a glass fiber filter maintained at a temperature at or
above the exhaust gas temperature up to a nominal 120 [deg]C (248 25 [deg]F). The particulate mass, which includes any
material that condenses at or above the filtration temperature, is
determined gravimetrically after the removal of uncombined water.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user to establish appropriate safety and health practices and to
determine the applicability of regulatory limitations prior to
performing this test method.
6.0 Equipment and Supplies
Same as section 6.0 of either Method 5 or Method 17.
7.0 Reagents and Standards
Same as section 7.0 of either Method 5 or Method 17.
8.0 Sample Collection, Preservation, Storage, and Transport
Same section 8.0 of either Method 5 or Method 17, except replace
section 8.2.1 of Method 5 with the following:
8.1 Determination of Measurement Site. The configuration of positive
pressure fabric filter structures frequently are not amenable to
emission testing according to the requirements of Method 1. Following
are several alternatives for determining measurement sites for positive
pressure fabric filters.
8.1.1 Stacks Meeting Method 1 Criteria. Use a measurement site as
specified in Method 1, section 11.1.
8.1.2 Short Stacks Not Meeting Method 1 Criteria. Use stack
extensions and the procedures in Method 1. Alternatively, use flow
straightening vanes of the ``egg-crate'' type (see Figure 5D-1). Locate
the measurement site downstream of the straightening vanes at a distance
equal to or greater than two times the average equivalent diameter of
the vane openings and at least one-half of the overall stack diameter
upstream of the stack outlet.
8.1.3 Roof Monitor or Monovent. (See Figure 5D-2). For a positive
pressure fabric filter equipped with a peaked roof monitor, ridge vent,
or other type of monovent, use a measurement site at the base of the
monovent. Examples of such locations are shown in Figure 5D-2. The
measurement site must be upstream of any exhaust point (e.g., louvered
vent).
8.1.4 Compartment Housing. Sample immediately downstream of the
filter bags directly above the tops of the bags as shown in the examples
in Figure 5D-2. Depending on the housing design, use sampling ports in
the housing walls or locate the sampling equipment within the
compartment housing.
[[Page 203]]
8.2 Determination of Number and Location of Traverse Points. Locate
the traverse points according to Method 1, section 11.3. Because a
performance test consists of at least three test runs and because of the
varied configurations of positive pressure fabric filters, there are
several schemes by which the number of traverse points can be determined
and the three test runs can be conducted.
8.2.1 Single Stacks Meeting Method 1 Criteria. Select the number of
traverse points according to Method 1. Sample all traverse points for
each test run.
8.2.2 Other Single Measurement Sites. For a roof monitor or
monovent, single compartment housing, or other stack not meeting Method
1 criteria, use at least 24 traverse points. For example, for a
rectangular measurement site, such as a monovent, use a balanced 5 x 5
traverse point matrix. Sample all traverse points for each test run.
8.2.3 Multiple Measurement Sites. Sampling from two or more stacks
or measurement sites may be combined for a test run, provided the
following guidelines are met:
8.2.3.1 All measurement sites up to 12 must be sampled. For more
than 12 measurement sites, conduct sampling on at least 12 sites or 50
percent of the sites, whichever is greater. The measurement sites
sampled should be evenly, or nearly evenly, distributed among the
available sites; if not, all sites are to be sampled.
8.2.3.2 The same number of measurement sites must be sampled for
each test run.
8.2.3.3 The minimum number of traverse points per test run is 24. An
exception to the 24-point minimum would be a test combining the sampling
from two stacks meeting Method 1 criteria for acceptable stack length,
and Method 1 specifies fewer than 12 points per site.
8.2.3.4 As long as the 24 traverse points per test run criterion is
met, the number of traverse points per measurement site may be reduced
to eight.
8.2.3.5 Alternatively, conduct a test run for each measurement site
individually using the criteria in section 8.2.1 or 8.2.2 to determine
the number of traverse points. Each test run shall count toward the
total of three required for a performance test. If more than three
measurement sites are sampled, the number of traverse points per
measurement site may be reduced to eight as long as at least 72 traverse
points are sampled for all the tests.
8.2.3.6 The following examples demonstrate the procedures for
sampling multiple measurement sites.
8.2.3.6.1 Example 1: A source with nine circular measurement sites
of equal areas may be tested as follows: For each test run, traverse
three measurement sites using four points per diameter (eight points per
measurement site). In this manner, test run number 1 will include
sampling from sites 1,2, and 3; run 2 will include samples from sites 4,
5, and 6; and run 3 will include sites 7, 8, and 9. Each test area may
consist of a separate test of each measurement site using eight points.
Use the results from all nine tests in determining the emission average.
8.2.3.6.2 Example 2: A source with 30 rectangular measurement sites
of equal areas may be tested as follows: For each of the three test
runs, traverse five measurement sites using a 3 x 3 matrix of traverse
points for each site. In order to distribute the sampling evenly over
all the available measurement sites while sampling only 50 percent of
the sites, number the sites consecutively from 1 to 30 and sample all
the even numbered (or odd numbered) sites. Alternatively, conduct a
separate test of each of 15 measurement sites using section 8.2.1 or
8.2.2 to determine the number and location of traverse points, as
appropriate.
8.2.3.6.3 Example 3: A source with two measurement sites of equal
areas may be tested as follows: For each test of three test runs,
traverse both measurement sites, using section 8.2.3 in determining the
number of traverse points. Alternatively, conduct two full emission test
runs for each measurement site using the criteria in section 8.2.1 or
8.2.2 to determine the number of traverse points.
8.2.3.7 Other test schemes, such as random determination of traverse
points for a large number of measurement sites, may be used with prior
approval from the Administrator.
8.3 Velocity Determination.
8.3.1 The velocities of exhaust gases from positive pressure
baghouses are often too low to measure accurately with the type S pitot
tube specified in Method 2 (i.e., velocity head <1.3 mm H2O
(0.05 in. H2O)). For these conditions, measure the gas flow
rate at the fabric filter inlet following the procedures outlined in
Method 2. Calculate the average gas velocity at the measurement site as
shown in section 12.2 and use this average velocity in determining and
maintaining isokinetic sampling rates.
8.3.2 Velocity determinations to determine and maintain isokinetic
rates at measurement sites with gas velocities within the range
measurable with the type S pitot tube (i.e., velocity head greater than
1.3 mm H2O (0.05 in. H2O)) shall be conducted
according to the procedures outlined in Method 2.
8.4 Sampling. Follow the procedures specified in sections 8.1
through 8.6 of Method 5 or sections 8.1 through 8.25 in Method 17 with
the exceptions as noted above.
8.5 Sample Recovery. Follow the procedures specified in section 8.7
of Method 5 or section 8.2 of Method 17.
9.0 Quality Control
9.1 Miscellaneous Quality Control Measures.
[[Page 204]]
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
8.0, 10.0..................... Sampling Ensures accurate
equipment leak measurement of stack
check and gas flow rate,
calibration. sample volume.
------------------------------------------------------------------------
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
10.0 Calibration and Standardization
Same as section 10.0 of either Method 5 or Method 17.
11.0 Analytical Procedure
Same as section 11.0 of either Method 5 or Method 17.
12.0 Data Analysis and Calculations
Same as section 12.0 of either Method 5 or Method 17 with the
following exceptions:
12.1 Nomenclature.
Ao = Measurement site(s) total cross-sectional area, m\2\
(ft\2\).
C or Cavg = Average concentration of PM for all n runs, mg/
scm (gr/scf).
Qi = Inlet gas volume flow rate, m\3\/sec (ft\3\/sec).
mi = Mass collected for run i of n, mg (gr).
To = Average temperature of gas at measurement site, [deg]K
([deg]R).
Ti = Average temperature of gas at inlet, [deg]K ([deg]R).
Voli = Sample volume collected for run i of n, scm (scf).
v = Average gas velocity at the measurement site(s), m/s (ft/s)
Qo = Total baghouse exhaust volumetric flow rate, m\3\/sec
(ft\3\/sec).
Qd = Dilution air flow rate, m\3\/sec (ft\3\/sec).
Tamb = Ambient Temperature, ([deg]K).
12.2 Average Gas Velocity. When following section 8.3.1, calculate
the average gas velocity at the measurement site as follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.140
12.3 Volumetric Flow Rate. Total volumetric flow rate may be
determined as follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.141
12.4 Dilution Air Flow Rate.
[GRAPHIC] [TIFF OMITTED] TR17OC00.142
12.5 Average PM Concentration. For multiple measurement sites,
calculate the average PM concentration as follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.143
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
Same as Method 5, section 17.0.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
[[Page 205]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.144
[[Page 206]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.145
Method 5E--Determination of Particulate Matter Emissions From the Wool
Fiberglass Insulation Manufacturing Industry
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 2, Method 3, and
Method 5.
1.0 Scope and Applications
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
[[Page 207]]
1.2 Applicability. This method is applicable for the determination
of PM emissions from wool fiberglass insulation manufacturing sources.
2.0 Summary of Method
Particulate matter is withdrawn isokinetically from the source and
is collected either on a glass fiber filter maintained at a temperature
in the range of 120 14 [deg]C (248 25 [deg]F) and in impingers in solutions of 0.1 N sodium
hydroxide (NaOH). The filtered particulate mass, which includes any
material that condenses at or above the filtration temperature, is
determined gravimetrically after the removal of uncombined water. The
condensed PM collected in the impinger solutions is determined as total
organic carbon (TOC) using a nondispersive infrared type of analyzer.
The sum of the filtered PM mass and the condensed PM is reported as the
total PM mass.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and to determine the applicability of regulatory limitations
prior to performing this test method.
5.2 Corrosive Reagents. The following reagents are hazardous.
Personal protective equipment and safe procedures are useful in
preventing chemical splashes. If contact occurs, immediately flush with
copious amounts of water at least 15 minutes. Remove clothing under
shower and decontaminate. Treat residual chemical burn as thermal burn.
5.2.1 Hydrochloric Acid (HCl). Highly toxic. Vapors are highly
irritating to eyes, skin, nose, and lungs, causing severe damage. May
cause bronchitis, pneumonia, or edema of lungs. Exposure to
concentrations of 0.13 to 0.2 percent in air can be lethal in minutes.
Will react with metals, producing hydrogen.
5.2.2 Sodium Hydroxide (NaOH). Causes severe damage to eye tissues
and to skin. Inhalation causes irritation to nose, throat, and lungs.
Reacts exothermically with limited amounts of water.
6.0 Equipment and Supplies
6.1 Sample Collection. Same as Method 5, section 6.1, with the
exception of the following:
6.1.1 Probe Liner. Same as described in section 6.1.1.2 of Method 5
except use only borosilicate or quartz glass liners.
6.1.2 Filter Holder. Same as described in section 6.1.1.5 of Method
5 with the addition of a leak-tight connection in the rear half of the
filter holder designed for insertion of a temperature sensor used for
measuring the sample gas exit temperature.
6.2 Sample Recovery. Same as Method 5, section 6.2, except three
wash bottles are needed instead of two and only glass storage bottles
and funnels may be used.
6.3 Sample Analysis. Same as Method 5, section 6.3, with the
additional equipment for TOC analysis as described below:
6.3.1 Sample Blender or Homogenizer. Waring type or ultrasonic.
6.3.2 Magnetic Stirrer.
6.3.3 Hypodermic Syringe. 0- to 100-[micro]l capacity.
6.3.4 Total Organic Carbon Analyzer. Rosemount Model 2100A analyzer
or equivalent and a recorder.
6.3.5 Beaker. 30-ml.
6.3.6 Water Bath. Temperature controlled.
6.3.7 Volumetric Flasks. 1000-ml and 500-ml.
7.0 Reagents and Standards
Unless otherwise indicated, it is intended that all reagents conform
to the specifications established by the Committee on Analytical
Reagents of the American Chemical Society, where such specifications are
available; otherwise, use the best available grade.
7.1 Sample Collection. Same as Method 5, section 7.1, with the
addition of 0.1 N NaOH (Dissolve 4 g of NaOH in water and dilute to 1
liter).
7.2 Sample Recovery. Same as Method 5, section 7.2, with the
addition of the following:
7.2.1 Water. Deionized distilled to conform to ASTM Specification D
1193-77 or 91 Type 3 (incorporated by reference--see Sec. 60.17). The
potassium permanganate (KMnO4) test for oxidizable organic
matter may be omitted when high concentrations of organic matter are not
expected to be present.
7.2.2 Sodium Hydroxide. Same as described in section 7.1.
7.3 Sample Analysis. Same as Method 5, section 7.3, with the
addition of the following:
7.3.1 Carbon Dioxide-Free Water. Distilled or deionized water that
has been freshly boiled for 15 minutes and cooled to room temperature
while preventing exposure to ambient air by using a cover vented with an
Ascarite tube.
7.3.2 Hydrochloric Acid. HCl, concentrated, with a dropper.
7.3.3 Organic Carbon Stock Solution. Dissolve 2.1254 g of dried
potassium biphthalate (HOOCC6H4COOK) in
CO2-free water, and dilute to 1 liter in a volumetric flask.
This solution contains 1000 mg/L organic carbon.
7.3.4 Inorganic Carbon Stock Solution. Dissolve 4.404 g anhydrous
sodium carbonate
[[Page 208]]
(Na2CO3.) in about 500 ml of CO2-free
water in a 1-liter volumetric flask. Add 3.497 g anhydrous sodium
bicarbonate (NaHCO3) to the flask, and dilute to 1 liter with
CO2 -free water. This solution contains 1000 mg/L inorganic
carbon.
7.3.5 Oxygen Gas. CO2 -free.
8.0 Sample Collection, Preservation, Storage, and Transport
8.1 Pretest Preparation and Preliminary Determinations. Same as
Method 5, sections 8.1 and 8.2, respectively.
8.2 Preparation of Sampling Train. Same as Method 5, section 8.3,
except that 0.1 N NaOH is used in place of water in the impingers. The
volumes of the solutions are the same as in Method 5.
8.3 Leak-Check Procedures, Sampling Train Operation, Calculation of
Percent Isokinetic. Same as Method 5, sections 8.4 through 8.6,
respectively.
8.4 Sample Recovery. Same as Method 5, sections 8.7.1 through 8.7.4,
with the addition of the following:
8.4.1 Save portions of the water, acetone, and 0.1 N NaOH used for
cleanup as blanks. Take 200 ml of each liquid directly from the wash
bottles being used, and place in glass sample containers labeled ``water
blank,'' ``acetone blank,'' and ``NaOH blank,'' respectively.
8.4.2 Inspect the train prior to and during disassembly, and note
any abnormal conditions. Treat the samples as follows:
8.4.2.1 Container No. 1. Same as Method 5, section 8.7.6.1.
8.4.2.2 Container No. 2. Use water to rinse the sample nozzle,
probe, and front half of the filter holder three times in the manner
described in section 8.7.6.2 of Method 5 except that no brushing is
done. Put all the water wash in one container, seal, and label.
8.4.2.3 Container No. 3. Rinse and brush the sample nozzle, probe,
and front half of the filter holder with acetone as described for
Container No. 2 in section 8.7.6.2 of Method 5.
8.4.2.4 Container No. 4. Place the contents of the silica gel
impinger in its original container as described for Container No. 3 in
section 8.7.6.3 of Method 5.
8.4.2.5 Container No. 5. Measure the liquid in the first three
impingers and record the volume or weight as described for the Impinger
Water in section 8.7.6.4 of Method 5. Do not discard this liquid, but
place it in a sample container using a glass funnel to aid in the
transfer from the impingers or graduated cylinder (if used) to the
sample container. Rinse each impinger thoroughly with 0.1 N NaOH three
times, as well as the graduated cylinder (if used) and the funnel, and
put these rinsings in the same sample container. Seal the container and
label to clearly identify its contents.
8.5 Sample Transport. Whenever possible, containers should be
shipped in such a way that they remain upright at all times.
9.0 Quality Control.
9.1 Miscellaneous Quality Control Measures.
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
8.3, 10.0..................... Sampling Ensures accurate
equipment leak- measurement of stack
check and gas flow rate,
calibration. sample volume.
10.1.2, 11.2.5.3.............. Repetitive Ensures precise
analyses. measurement of total
carbon and inorganic
carbon concentration
of samples, blank,
and standards.
10.1.4........................ TOC analyzer Ensures linearity of
calibration. analyzer response to
standards.
------------------------------------------------------------------------
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
10.0 Calibration and Standardization
Same as Method 5, section 10.0, with the addition of the following
procedures for calibrating the total organic carbon analyzer:
10.1 Preparation of Organic Carbon Standard Curve.
10.1.1 Add 10 ml, 20 ml, 30 ml, 40 ml, and 50 ml of the organic
carbon stock solution to a series of five 1000-ml volumetric flasks. Add
30 ml, 40 ml, and 50 ml of the same solution to a series of three 500-ml
volumetric flasks. Dilute the contents of each flask to the mark using
CO2-free water. These flasks contain 10, 20, 30, 40, 50, 60,
80, and 100 mg/L organic carbon, respectively.
10.1.2 Use a hypodermic syringe to withdraw a 20- to 50-[micro]l
aliquot from the 10 mg/L standard solution and inject it into the total
carbon port of the analyzer. Measure the peak height. Repeat the
injections until three consecutive peaks are obtained within 10 percent
of their arithmetic mean. Repeat this procedure for the remaining
organic carbon standard solutions.
10.1.3 Calculate the corrected peak height for each standard by
deducting the blank correction (see section 11.2.5.3) as follows:
[[Page 209]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.146
Where:
A = Peak height of standard or sample, mm or other appropriate unit.
B = Peak height of blank, mm or other appropriate unit.
10.1.4 Prepare a linear regression plot of the arithmetic mean of
the three consecutive peak heights obtained for each standard solution
against the concentration of that solution. Calculate the calibration
factor as the inverse of the slope of this curve. If the product of the
arithmetic mean peak height for any standard solution and the
calibration factor differs from the actual concentration by more than 5
percent, remake and reanalyze that standard.
10.2 Preparation of Inorganic Carbon Standard Curve. Repeat the
procedures outlined in sections 10.1.1 through 10.1.4, substituting the
inorganic carbon stock solution for the organic carbon stock solution,
and the inorganic carbon port of the analyzer for the total carbon port.
11.0 Analytical Procedure
11.1 Record the data required on a sheet such as the one shown in
Figure 5-6 of Method 5.
11.2 Handle each sample container as follows:
11.2.1 Container No. 1. Same as Method 5, section 11.2.1, except
that the filters must be dried at 20 6 [deg]C (68
10 [deg]F) and ambient pressure.
11.2.2 Containers No. 2 and No. 3. Same as Method 5, section 11.2.2,
except that evaporation of the samples must be at 20 6 [deg]C (68 10 [deg]F) and
ambient pressure.
11.2.3 Container No. 4. Same as Method 5, section 11.2.3.
11.2.4 ``Water Blank'' and ``Acetone Blank'' Containers. Determine
the water and acetone blank values following the procedures for the
``Acetone Blank'' container in section 11.2.4 of Method 5. Evaporate the
samples at ambient temperature (20 6 [deg]C (68
10 [deg]F)) and pressure.
11.2.5 Container No. 5. For the determination of total organic
carbon, perform two analyses on successive identical samples, i.e.,
total carbon and inorganic carbon. The desired quantity is the
difference between the two values obtained. Both analyses are based on
conversion of sample carbon into carbon dioxide for measurement by a
nondispersive infrared analyzer. Results of analyses register as peaks
on a strip chart recorder.
11.2.5.1 The principal differences between the operating parameters
for the two channels involve the combustion tube packing material and
temperature. In the total carbon channel, a high temperature (950 [deg]C
(1740 [deg]F)) furnace heats a Hastelloy combustion tube packed with
cobalt oxide-impregnated asbestos fiber. The oxygen in the carrier gas,
the elevated temperature, and the catalytic effect of the packing result
in oxidation of both organic and inorganic carbonaceous material to
CO2, and steam. In the inorganic carbon channel, a low
temperature (150 [deg]C (300 [deg]F)) furnace heats a glass tube
containing quartz chips wetted with 85 percent phosphoric acid. The acid
liberates CO2 and steam from inorganic carbonates. The
operating temperature is below that required to oxidize organic matter.
Follow the manufacturer's instructions for assembly, testing,
calibration, and operation of the analyzer.
11.2.5.2 As samples collected in 0.1 N NaOH often contain a high
measure of inorganic carbon that inhibits repeatable determinations of
TOC, sample pretreatment is necessary. Measure and record the liquid
volume of each sample (or impinger contents). If the sample contains
solids or immiscible liquid matter, homogenize the sample with a blender
or ultrasonics until satisfactory repeatability is obtained. Transfer a
representative portion of 10 to 15 ml to a 30-ml beaker, and acidify
with about 2 drops of concentrated HCl to a pH of 2 or less. Warm the
acidified sample at 50 [deg]C (120 [deg]F) in a water bath for 15
minutes.
11.2.5.3 While stirring the sample with a magnetic stirrer, use a
hypodermic syringe to withdraw a 20-to 50-[micro]1 aliquot from the
beaker. Analyze the sample for total carbon and calculate its corrected
mean peak height according to the procedures outlined in sections 10.1.2
and 10.1.3. Similarly analyze an aliquot of the sample for inorganic
carbon. Repeat the analyses for all the samples and for the 0.1 N NaOH
blank.
11.2.5.4 Ascertain the total carbon and inorganic carbon
concentrations (CTC and CIC, respectively) of each
sample and blank by comparing the corrected mean peak heights for each
sample and blank to the appropriate standard curve.
Note: If samples must be diluted for analysis, apply an appropriate
dilution factor.
12.0 Data Analysis and Calculations
Same as Method 5, section 12.0, with the addition of the following:
12.1 Nomenclature.
Cc = Concentration of condensed particulate matter in stack
gas, gas dry basis, corrected to standard conditions, g/dscm
(gr/dscf).
CIC = Concentration of condensed TOC in the liquid sample,
from section 11.2.5, mg/L.
[[Page 210]]
Ct = Total particulate concentration, dry basis, corrected to
standard conditions, g/dscm (gr/dscf).
CTC = Concentration of condensed TOC in the liquid sample,
from section 11.2.5, mg/L.
CTOC = Concentration of condensed TOC in the liquid sample,
mg/L.
mTOC = Mass of condensed TOC collected in the impingers, mg.
Vm(std) = Volume of gas sample measured by the dry gas meter,
corrected to standard conditions, from section 12.3 of Method
5, dscm (dscf).
Vs = Total volume of liquid sample, ml.
12.2 Concentration of Condensed TOC in Liquid Sample.
[GRAPHIC] [TIFF OMITTED] TR17OC00.148
12.3 Mass of Condensed TOC Collected.
[GRAPHIC] [TIFF OMITTED] TR17OC00.149
Where:
0.001 = Liters per milliliter.
12.4 Concentration of Condensed Particulate Material.
[GRAPHIC] [TIFF OMITTED] TR17OC00.150
Where:
K4 = 0.001 g/mg for metric units.
= 0.0154 gr/mg for English units.
12.5 Total Particulate Concentration.
[GRAPHIC] [TIFF OMITTED] TR17OC00.151
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Alternative Procedures
16.1 Total Organic Carbon Analyzer. Tekmar-Dohrmann analyzers using
the single injection technique may be used as an alternative to
Rosemount Model 2100A analyzers.
17.0 References.
Same as section 17.0 of Method 5, with the addition of the
following:
1. American Public Health Association, American Water Works
Association, Water Pollution Control Federation. Standard Methods for
the Examination of Water and Wastewater. Fifteenth Edition. Washington,
D.C. 1980.
18.0 Tables, Diagrams, Flowcharts, and Validation Data [Reserved]
Method 5F--Determination of Nonsulfate Particulate Matter Emissions From
Stationary Sources
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 2, Method 3, and
Method 5.
1.0 Scope and Applications
1.1 Analyte. Nonsulfate particulate matter (PM). No CAS number
assigned.
1.2 Applicability. This method is applicable for the determination
of nonsulfate PM emissions from stationary sources. Use of this method
must be specified by an applicable subpart of the standards, or approved
by the Administrator for a particular application.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
Particulate matter is withdrawn isokinetically from the source and
collected on a filter maintained at a temperature in the range 160
14 [deg]C (320 25 [deg]F).
The collected sample is extracted with water. A portion of the extract
is analyzed for sulfate content by ion chromatography. The remainder is
neutralized with ammonium hydroxide (NH4OH), dried, and
weighed. The weight of sulfate in the sample is calculated as ammonium
sulfate ((NH4)2SO4), and is subtracted
from the total particulate weight; the result is reported as nonsulfate
particulate matter.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and to determine the applicability of regulatory limitations
prior to performing this test method.
[[Page 211]]
6.0 Equipment and Supplies
6.1 Sample Collection and Recovery. Same as Method 5, sections 6.1
and 6.2, respectively.
6.2 Sample Analysis. Same as Method 5, section 6.3, with the
addition of the following:
6.2.1 Erlenmeyer Flasks. 125-ml, with ground glass joints.
6.2.2 Air Condenser. With ground glass joint compatible with the
Erlenmeyer flasks.
6.2.3 Beakers. 600-ml.
6.2.4 Volumetric Flasks. 1-liter, 500-ml (one for each sample), 200-
ml, and 50-ml (one for each sample and standard).
6.2.5 Pipet. 5-ml (one for each sample and standard).
6.2.6 Ion Chromatograph. The ion chromatograph should have at least
the following components.
6.2.6.1 Columns. An anion separation column or other column capable
of resolving the sulfate ion from other species present and a standard
anion suppressor column. Suppressor columns are produced as proprietary
items; however, one can be produced in the laboratory using the resin
available from BioRad Company, 32nd and Griffin Streets, Richmond,
California. Other systems which do not use suppressor columns may also
be used.
6.2.6.2 Pump. Capable of maintaining a steady flow as required by
the system.
6.2.6.3 Flow Gauges. Capable of measuring the specified system flow
rate.
6.2.6.4 Conductivity Detector.
6.2.6.5 Recorder. Compatible with the output voltage range of the
detector.
7.0 Reagents and Standards
Unless otherwise indicated, it is intended that all reagents conform
to the specifications established by the Committee on Analytical
Reagents of the American Chemical Society, where such specifications are
available; otherwise, use the best available grade.
7.1 Sample Collection. Same as Method 5, section 7.1.
7.2 Sample Recovery. Same as Method 5, section 7.2, with the
addition of the following:
7.2.1 Water. Deionized distilled, to conform to ASTM D 1193-77 or 91
Type 3 (incorporated by reference--see Sec. 60.17). The potassium
permanganate (KMnO4) test for oxidizable organic matter may
be omitted when high concentrations of organic matter are not expected
to be present.
7.3 Analysis. Same as Method 5, section 7.3, with the addition of
the following:
7.3.1 Water. Same as in section 7.2.1.
7.3.2 Stock Standard Solution, 1 mg
(NH4)2SO4/ml. Dry an adequate amount of
primary standard grade ammonium sulfate
((NH4)2SO4) at 105 to 110 [deg]C (220
to 230 [deg]F) for a minimum of 2 hours before preparing the standard
solution. Then dissolve exactly 1.000 g of dried
(NH4)2SO4 in water in a 1-liter
volumetric flask, and dilute to 1 liter. Mix well.
7.3.3 Working Standard Solution, 25 [micro]g
(NH4)2SO4/ml. Pipet 5 ml of the stock
standard solution into a 200-ml volumetric flask. Dilute to 200 ml with
water.
7.3.4 Eluent Solution. Weigh 1.018 g of sodium carbonate
(Na2CO3) and 1.008 g of sodium bicarbonate
(NaHCO3), and dissolve in 4 liters of water. This solution is
0.0024 M Na2CO3/0.003 M NaHCO3. Other
eluents appropriate to the column type and capable of resolving sulfate
ion from other species present may be used.
7.3.5 Ammonium Hydroxide. Concentrated, 14.8 M.
7.3.6 Phenolphthalein Indicator. 3,3-Bis(4-hydroxyphenyl)-1-(3H)-
isobenzo-furanone. Dissolve 0.05 g in 50 ml of ethanol and 50 ml of
water.
8.0 Sample Collection, Preservation, Storage, and Transport
Same as Method 5, section 8.0, with the exception of the following:
8.1 Sampling Train Operation. Same as Method 5, section 8.5, except
that the probe outlet and filter temperatures shall be maintained at 160
14 [deg]C (320 25 [deg]F).
8.2 Sample Recovery. Same as Method 5, section 8.7, except that the
recovery solvent shall be water instead of acetone, and a clean filter
from the same lot as those used during testing shall be saved for
analysis as a blank.
9.0 Quality Control
9.1 Miscellaneous Quality Control Measures
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
8.3, 10.0..................... Sampling Ensures accurate
equipment leak measurement of stack
check and gas flow rate,
calibration. sample volume.
10.1.2, 11.2.5.3.............. Repetitive Ensures precise
analyses. measurement of total
carbon and inorganic
carbon concentration
of samples, blank,
and standards.
------------------------------------------------------------------------
[[Page 212]]
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
10.0 Calibration and Standardization
Same as Method 5, section 10.0, with the addition of the following:
10.1 Determination of Ion Chromatograph Calibration Factor S.
Prepare a series of five standards by adding 1.0, 2.0, 4.0, 6.0, and
10.0 ml of working standard solution (25 [micro]g/ml) to a series of
five 50-ml volumetric flasks. (The standard masses will equal 25, 50,
100, 150, and 250 [micro]g.) Dilute each flask to the mark with water,
and mix well. Analyze each standard according to the chromatograph
manufacturer's instructions. Take peak height measurements with
symmetrical peaks; in all other cases, calculate peak areas. Prepare or
calculate a linear regression plot of the standard masses in [micro]g
(x-axis) versus their responses (y-axis). From this line, or equation,
determine the slope and calculate its reciprocal which is the
calibration factor, S. If any point deviates from the line by more than
7 percent of the concentration at that point, remake and reanalyze that
standard. This deviation can be determined by multiplying S times the
response for each standard. The resultant concentrations must not differ
by more than 7 percent from each known standard mass (i.e., 25, 50, 100,
150, and 250 [micro]g).
10.2 Conductivity Detector. Calibrate according to manufacturer's
specifications prior to initial use.
11.0 Analytical Procedure
11.1 Sample Extraction.
11.1.1 Note on the analytical data sheet, the level of the liquid in
the container, and whether any sample was lost during shipment. If a
noticeable amount of leakage has occurred, either void the sample or use
methods, subject to the approval of the Administrator, to correct the
final results.
11.1.2 Cut the filter into small pieces, and place it in a 125-ml
Erlenmeyer flask with a ground glass joint equipped with an air
condenser. Rinse the shipping container with water, and pour the rinse
into the flask. Add additional water to the flask until it contains
about 75 ml, and place the flask on a hot plate. Gently reflux the
contents for 6 to 8 hours. Cool the solution, and transfer it to a 500-
ml volumetric flask. Rinse the Erlenmeyer flask with water, and transfer
the rinsings to the volumetric flask including the pieces of filter.
11.1.3 Transfer the probe rinse to the same 500-ml volumetric flask
with the filter sample. Rinse the sample bottle with water, and add the
rinsings to the volumetric flask. Dilute the contents of the flask to
the mark with water.
11.1.4 Allow the contents of the flask to settle until all solid
material is at the bottom of the flask. If necessary, remove and
centrifuge a portion of the sample.
11.1.5 Repeat the procedures outlined in sections 11.1.1 through
11.1.4 for each sample and for the filter blank.
11.2 Sulfate (SO4) Analysis.
11.2.1 Prepare a standard calibration curve according to the
procedures outlined in section 10.1.
11.2.2 Pipet 5 ml of the sample into a 50-ml volumetric flask, and
dilute to 50 ml with water. (Alternatively, eluent solution may be used
instead of water in all sample, standard, and blank dilutions.) Analyze
the set of standards followed by the set of samples, including the
filter blank, using the same injection volume used for the standards.
11.2.3 Repeat the analyses of the standards and the samples, with
the standard set being done last. The two peak height or peak area
responses for each sample must agree within 5 percent of their
arithmetic mean for the analysis to be valid. Perform this analysis
sequence on the same day. Dilute any sample and the blank with equal
volumes of water if the concentration exceeds that of the highest
standard.
11.2.4 Document each sample chromatogram by listing the following
analytical parameters: injection point, injection volume, sulfate
retention time, flow rate, detector sensitivity setting, and recorder
chart speed.
11.3 Sample Residue.
11.3.1 Transfer the remaining contents of the volumetric flask to a
tared 600-ml beaker or similar container. Rinse the volumetric flask
with water, and add the rinsings to the tared beaker. Make certain that
all particulate matter is transferred to the beaker. Evaporate the water
in an oven at 105 [deg]C (220 [deg]F) until only about 100 ml of water
remains. Remove the beakers from the oven, and allow them to cool.
11.3.2 After the beakers have cooled, add five drops of
phenolphthalein indicator, and then add concentrated ammonium hydroxide
until the solution turns pink. Return the samples to the oven at 105
[deg]C (220 [deg]F), and evaporate the samples to dryness. Cool the
samples in a desiccator, and weigh the samples to constant weight.
12.0 Data Analysis and Calculations
Same as Method 5, section 12.0, with the addition of the following:
12.1 Nomenclature.
CW = Water blank residue concentration, mg/ml.
F = Dilution factor (required only if sample dilution was needed to
reduce the concentration into the range of calibration).
HS = Arithmetic mean response of duplicate sample analyses,
mm for height or mm2 for area.
[[Page 213]]
Hb = Arithmetic mean response of duplicate filter blank
analyses, mm for height or mm2 for area.
mb = Mass of beaker used to dry sample, mg.
mf = Mass of sample filter, mg.
mn = Mass of nonsulfate particulate matter in the sample as
collected, mg.
ms = Mass of ammonium sulfate in the sample as collected, mg.
mt = Mass of beaker, filter, and dried sample, mg.
mw = Mass of residue after evaporation of water blank, mg.
S = Calibration factor, [micro]g/mm.
Vb = Volume of water blank, ml.
VS = Volume of sample collected, 500 ml.
12.2 Water Blank Concentration.
[GRAPHIC] [TIFF OMITTED] TR17OC00.152
12.3 Mass of Ammonium Sulfate.
[GRAPHIC] [TIFF OMITTED] TR17OC00.153
Where:
100 = Aliquot factor, 495 ml/5 ml
1000 = Constant, [micro]g/mg
12.4 Mass of Nonsulfate Particulate Matter.
[GRAPHIC] [TIFF OMITTED] TR17OC00.154
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Alternative Procedures
16.1 The following procedure may be used as an alternative to the
procedure in section 11.0
16.1.1 Apparatus. Same as for Method 6, sections 6.3.3 to 6.3.6 with
the following additions.
16.1.1.1 Beakers. 250-ml, one for each sample, and 600-ml.
16.1.1.2 Oven. Capable of maintaining temperatures of 75 5 [deg]C (167 9 [deg]F) and 105
5 [deg]C (221 9 [deg]F).
16.1.1.3 Buchner Funnel.
16.1.1.4 Glass Columns. 25-mm x 305-mm (1-in. x 12-in.) with Teflon
stopcock.
16.1.1.5 Volumetric Flasks. 50-ml and 500-ml, one set for each
sample, and 100-ml, 200-ml, and 1000-ml.
16.1.1.6 Pipettes. Two 20-ml and one 200-ml, one set for each
sample, and 5-ml.
16.1.1.7 Filter Flasks. 500-ml.
16.1.1.8 Polyethylene Bottle. 500-ml, one for each sample.
16.1.2 Reagents. Same as Method 6, sections 7.3.2 to 7.3.5 with the
following additions:
16.1.2.1 Water, Ammonium Hydroxide, and Phenolphthalein. Same as
sections 7.2.1, 7.3.5, and 7.3.6 of this method, respectively.
16.1.2.2 Filter. Glass fiber to fit Buchner funnel.
16.1.2.3 Hydrochloric Acid (HCl), 1 m. Add 8.3 ml of concentrated
HCl (12 M) to 50 ml of water in a 100-ml volumetric flask. Dilute to 100
ml with water.
16.1.2.4 Glass Wool.
16.1.2.5 Ion Exchange Resin. Strong cation exchange resin, hydrogen
form, analytical grade.
16.1.2.6 pH Paper. Range of 1 to 7.
16.1.3 Analysis.
16.1.3.1 Ion Exchange Column Preparation. Slurry the resin with 1 M
HCl in a 250-ml beaker, and allow to stand overnight. Place 2.5 cm (1
in.) of glass wool in the bottom of the glass column. Rinse the slurried
resin twice with water. Resuspend the resin in water, and pour
sufficient resin into the column to make a bed 5.1 cm (2 in.) deep. Do
not allow air bubbles to become entrapped in the resin or glass wool to
avoid channeling, which may produce erratic results. If necessary, stir
the resin with a glass rod to remove air bubbles, after the column has
been prepared, never let the liquid level fall below the top of the
upper glass wool plug. Place a 2.5-cm (1-in.) plug of glass wool on top
of the resin. Rinse the column with water until the eluate gives a pH of
5 or greater as measured with pH paper.
16.1.3.2 Sample Extraction. Followup the procedure given in section
11.1.3 except do not dilute the sample to 500 ml.
16.1.3.3 Sample Residue.
16.1.3.3.1 Place at least one clean glass filter for each sample in
a Buchner funnel, and rinse the filters with water. Remove the filters
from the funnel, and dry them in an oven at 105 5
[deg]C (221 9 [deg]F); then cool in a desiccator.
Weigh each filter to constant weight according to the procedure in
Method 5, section 11.0. Record the weight of each filter to the nearest
0.1 mg.
16.1.3.3.2 Assemble the vacuum filter apparatus, and place one of
the clean, tared glass fiber filters in the Buchner funnel. Decant the
liquid portion of the extracted sample (Section 16.1.3.2) through the
tared glass fiber filter into a clean, dry, 500-ml filter flask. Rinse
all the particulate matter remaining in the volumetric flask onto the
glass fiber filter with water. Rinse the particulate matter with
additional water.
[[Page 214]]
Transfer the filtrate to a 500-ml volumetric flask, and dilute to 500 ml
with water. Dry the filter overnight at 105 5
[deg]C (221 9 [deg]F), cool in a desiccator, and
weigh to the nearest 0.1 mg.
16.1.3.3.3 Dry a 250-ml beaker at 75 5 [deg]C
(167 9 [deg]F), and cool in a desiccator; then
weigh to constant weight to the nearest 0.1 mg. Pipette 200 ml of the
filtrate that was saved into a tared 250-ml beaker; add five drops of
phenolphthalein indicator and sufficient concentrated ammonium hydroxide
to turn the solution pink. Carefully evaporate the contents of the
beaker to dryness at 75 5 [deg]C (167 9 [deg]F). Check for dryness every 30 minutes. Do not
continue to bake the sample once it has dried. Cool the sample in a
desiccator, and weigh to constant weight to the nearest 0.1 mg.
16.1.3.4 Sulfate Analysis. Adjust the flow rate through the ion
exchange column to 3 ml/min. Pipette a 20-ml aliquot of the filtrate
onto the top of the ion exchange column, and collect the eluate in a 50-
ml volumetric flask. Rinse the column with two 15-ml portions of water.
Stop collection of the eluate when the volume in the flask reaches 50-
ml. Pipette a 20-ml aliquot of the eluate into a 250-ml Erlenmeyer
flask, add 80 ml of 100 percent isopropanol and two to four drops of
thorin indicator, and titrate to a pink end point using 0.0100 N barium
perchlorate. Repeat and average the titration volumes. Run a blank with
each series of samples. Replicate titrations must agree within 1 percent
or 0.2 ml, whichever is larger. Perform the ion exchange and titration
procedures on duplicate portions of the filtrate. Results should agree
within 5 percent. Regenerate or replace the ion exchange resin after 20
sample aliquots have been analyzed or if the end point of the titration
becomes unclear.
Note: Protect the 0.0100 N barium perchlorate solution from
evaporation at all times.
16.1.3.5 Blank Determination. Begin with a sample of water of the
same volume as the samples being processed and carry it through the
analysis steps described in sections 16.1.3.3 and 16.1.3.4. A blank
value larger than 5 mg should not be subtracted from the final
particulate matter mass. Causes for large blank values should be
investigated and any problems resolved before proceeding with further
analyses.
16.1.4 Calibration. Calibrate the barium perchlorate solutions as in
Method 6, section 10.5.
16.1.5 Calculations.
16.1.5.1 Nomenclature. Same as section 12.1 with the following
additions:
ma = Mass of clean analytical filter, mg.
md = Mass of dissolved particulate matter, mg.
me = Mass of beaker and dissolved particulate matter after
evaporation of filtrate, mg.
mp = Mass of insoluble particulate matter, mg.
mr = Mass of analytical filter, sample filter, and insoluble
particulate matter, mg.
mbk = Mass of nonsulfate particulate matter in blank sample,
mg.
mn = Mass of nonsulfate particulate matter, mg.
ms = Mass of Ammonium sulfate, mg.
N = Normality of Ba(ClO4) titrant, meq/ml.
Va = Volume of aliquot taken for titration, 20 ml.
Vc = Volume of titrant used for titration blank, ml.
Vd = Volume of filtrate evaporated, 200 ml.
Ve = Volume of eluate collected, 50 ml.
Vf = Volume of extracted sample, 500 ml.
Vi = Volume of filtrate added to ion exchange column, 20 ml.
Vt = Volume of Ba(C104)2 titrant, ml.
W = Equivalent weight of ammonium sulfate, 66.07 mg/meq.
16.1.5.2 Mass of Insoluble Particulate Matter.
[GRAPHIC] [TIFF OMITTED] TR17OC00.155
16.1.5.3 Mass of Dissolved Particulate Matter.
[GRAPHIC] [TIFF OMITTED] TR17OC00.156
16.1.5.4 Mass of Ammonium Sulfate.
[GRAPHIC] [TIFF OMITTED] TR17OC00.157
16.1.5.5 Mass of Nonsulfate Particulate Matter.
[GRAPHIC] [TIFF OMITTED] TR17OC00.158
17.0 References
Same as Method 5, section 17.0, with the addition of the following:
1. Mulik, J.D. and E. Sawicki. Ion Chromatographic Analysis of
Environmental Pollutants. Ann Arbor, Ann Arbor Science Publishers, Inc.
Vol. 2, 1979.
2. Sawicki, E., J.D. Mulik, and E. Wittgenstein. Ion Chromatographic
Analysis of Environmental Pollutants. Ann Arbor, Ann Arbor Science
Publishers, Inc. Vol. 1. 1978.
3. Siemer, D.D. Separation of Chloride and Bromide from Complex
Matrices Prior to Ion Chromatographic Determination. Analytical
Chemistry 52(12): 1874-1877. October 1980.
4. Small, H., T.S. Stevens, and W.C. Bauman. Novel Ion Exchange
Chromatographic Method Using
[[Page 215]]
Conductimetric Determination. Analytical Chemistry. 47(11):1801. 1975.
18.0 Tables, Diagrams, Flowcharts, and Validation Data [Reserved]
Method 5G--Determination of Particulate Matter Emissions From Wood
Heaters (Dilution Tunnel Sampling Location)
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 2, Method 3,
Method 4, Method 5, Method 5H, and Method 28.
1.0 Scope and Application
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
1.2 Applicability. This method is applicable for the determination
of PM emissions from wood heaters.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 The exhaust from a wood heater is collected with a total
collection hood, and is combined with ambient dilution air. Particulate
matter is withdrawn proportionally from a single point in a sampling
tunnel, and is collected on two glass fiber filters in series. The
filters are maintained at a temperature of no greater than 32 [deg]C (90
[deg]F). The particulate mass is determined gravimetrically after the
removal of uncombined water.
2.2 There are three sampling train approaches described in this
method: (1) One dual-filter dry sampling train operated at about 0.015
m\3\/min (0.5 cfm), (2) One dual-filter plus impingers sampling train
operated at about 0.015 m\3\/min (0.5 cfm), and (3) two dual-filter dry
sampling trains operated simultaneously at any flow rate. Options (2)
and (3) are referenced in section 16.0 of this method. The dual-filter
dry sampling train equipment and operation, option (1), are described in
detail in this method.
3.0 Definitions [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and to determine the applicability of regulatory limitations
prior to performing this test method.
6.0 Equipment and Supplies
6.1 Sample Collection. The following items are required for sample
collection:
6.1.1 Sampling Train. The sampling train configuration is shown in
Figure 5G-1 and consists of the following components:
6.1.1.1 Probe. Stainless steel (e.g., 316 or grade more corrosion
resistant) or glass about 9.5 mm (\3/8\ in.) I.D., 0.6 m (24 in.) in
length. If made of stainless steel, the probe shall be constructed from
seamless tubing.
6.1.1.2 Pitot Tube. Type S, as described in section 6.1 of Method 2.
The Type S pitot tube assembly shall have a known coefficient,
determined as outlined in Method 2, section 10. Alternatively, a
standard pitot may be used as described in Method 2, section 6.1.2.
6.1.1.3 Differential Pressure Gauge. Inclined manometer or
equivalent device, as described in Method 2, section 6.2. One manometer
shall be used for velocity head ([Delta]p) readings and another
(optional) for orifice differential pressure readings ([Delta]H).
6.1.1.4 Filter Holders. Two each made of borosilicate glass,
stainless steel, or Teflon, with a glass frit or stainless steel filter
support and a silicone rubber, Teflon, or Viton gasket. The holder
design shall provide a positive seal against leakage from the outside or
around the filters. The filter holders shall be placed in series with
the backup filter holder located 25 to 100 mm (1 to 4 in.) downstream
from the primary filter holder. The filter holder shall be capable of
holding a filter with a 100 mm (4 in.) diameter, except as noted in
section 16.
6.1.1.5 Filter Temperature Monitoring System. A temperature sensor
capable of measuring temperature to within 3
[deg]C (5 [deg]F). The sensor shall be installed
at the exit side of the front filter holder so that the sensing tip of
the temperature sensor is in direct contact with the sample gas or in a
thermowell as shown in Figure 5G-1. The temperature sensor shall comply
with the calibration specifications in Method 2, section 10.3.
Alternatively, the sensing tip of the temperature sensor may be
installed at the inlet side of the front filter holder.
6.1.1.6 Dryer. Any system capable of removing water from the sample
gas to less than 1.5 percent moisture (volume percent) prior to the
metering system. The system shall include a temperature sensor for
demonstrating that sample gas temperature exiting the dryer is less than
20 [deg]C (68 [deg]F).
6.1.1.7 Metering System. Same as Method 5, section 6.1.1.9.
6.1.2 Barometer. Same as Method 5, section 6.1.2.
6.1.3 Dilution Tunnel Gas Temperature Measurement. A temperature
sensor capable
[[Page 216]]
of measuring temperature to within 3 [deg]C
(5 [deg]F).
6.1.4 Dilution Tunnel. The dilution tunnel apparatus is shown in
Figure 5G-2 and consists of the following components:
6.1.4.1 Hood. Constructed of steel with a minimum diameter of 0.3 m
(1 ft) on the large end and a standard 0.15 to 0.3 m (0.5 to 1 ft)
coupling capable of connecting to standard 0.15 to 0.3 m (0.5 to 1 ft)
stove pipe on the small end.
6.1.4.2 90[deg] Elbows. Steel 90[deg] elbows, 0.15 to 0.3 m (0.5 to
1 ft) in diameter for connecting mixing duct, straight duct and optional
damper assembly. There shall be at least two 90[deg] elbows upstream of
the sampling section (see Figure 5G-2).
6.1.4.3 Straight Duct. Steel, 0.15 to 0.3 m (0.5 to 1 ft) in
diameter to provide the ducting for the dilution apparatus upstream of
the sampling section. Steel duct, 0.15 m (0.5 ft) in diameter shall be
used for the sampling section. In the sampling section, at least 1.2 m
(4 ft) downstream of the elbow, shall be two holes (velocity traverse
ports) at 90[deg] to each other of sufficient size to allow entry of the
pitot for traverse measurements. At least 1.2 m (4 ft) downstream of the
velocity traverse ports, shall be one hole (sampling port) of sufficient
size to allow entry of the sampling probe. Ducts of larger diameter may
be used for the sampling section, provided the specifications for
minimum gas velocity and the dilution rate range shown in section 8 are
maintained. The length of duct from the hood inlet to the sampling ports
shall not exceed 9.1 m (30 ft).
6.1.4.4 Mixing Baffles. Steel semicircles (two) attached at 90[deg]
to the duct axis on opposite sides of the duct midway between the two
elbows upstream of sampling section. The space between the baffles shall
be about 0.3 m (1 ft).
6.1.4.5 Blower. Squirrel cage or other fan capable of extracting gas
from the dilution tunnel of sufficient flow to maintain the velocity and
dilution rate specifications in section 8 and exhausting the gas to the
atmosphere.
6.2 Sample Recovery. The following items are required for sample
recovery: probe brushes, wash bottles, sample storage containers, petri
dishes, and funnel. Same as Method 5, sections 6.2.1 through 6.2.4, and
6.2.8, respectively.
6.3 Sample Analysis. The following items are required for sample
analysis: glass weighing dishes, desiccator, analytical balance, beakers
(250-ml or smaller), hygrometer, and temperature sensor. Same as Method
5, sections 6.3.1 through 6.3.3 and 6.3.5 through 6.3.7, respectively.
7.0 Reagents and Standards
7.1 Sample Collection. The following reagents are required for
sample collection:
7.1.1 Filters. Glass fiber filters with a minimum diameter of 100 mm
(4 in.), without organic binder, exhibiting at least 99.95 percent
efficiency (<0.05 percent penetration) on 0.3-micron dioctyl phthalate
smoke particles. Gelman A/E 61631 has been found acceptable for this
purpose.
7.1.2 Stopcock Grease. Same as Method 5, section 7.1.5. 7.2 Sample
Recovery. Acetone-reagent grade, same as Method 5, section 7.2.
7.3 Sample Analysis. Two reagents are required for the sample
analysis:
7.3.1 Acetone. Same as in section 7.2.
7.3.2 Desiccant. Anhydrous calcium sulfate, calcium chloride, or
silica gel, indicating type.
8.0 Sample Collection, Preservation, Transport, and Storage
8.1 Dilution Tunnel Assembly and Cleaning. A schematic of a dilution
tunnel is shown in Figure 5G-2. The dilution tunnel dimensions and other
features are described in section 6.1.4. Assemble the dilution tunnel,
sealing joints and seams to prevent air leakage. Clean the dilution
tunnel with an appropriately sized wire chimney brush before each
certification test.
8.2 Draft Determination. Prepare the wood heater as in Method 28,
section 6.2.1. Locate the dilution tunnel hood centrally over the wood
heater stack exhaust. Operate the dilution tunnel blower at the flow
rate to be used during the test run. Measure the draft imposed on the
wood heater by the dilution tunnel (i.e., the difference in draft
measured with and without the dilution tunnel operating) as described in
Method 28, section 6.2.3. Adjust the distance between the top of the
wood heater stack exhaust and the dilution tunnel hood so that the
dilution tunnel induced draft is less than 1.25 Pa (0.005 in.
H2O). Have no fire in the wood heater, close the wood heater
doors, and open fully the air supply controls during this check and
adjustment.
8.3 Pretest Ignition. Same as Method 28, section 8.7.
8.4 Smoke Capture. During the pretest ignition period, operate the
dilution tunnel and visually monitor the wood heater stack exhaust.
Operate the wood heater with the doors closed and determine that 100
percent of the exhaust gas is collected by the dilution tunnel hood. If
less than 100 percent of the wood heater exhaust gas is collected,
adjust the distance between the wood heater stack and the dilution
tunnel hood until no visible exhaust gas is escaping. Stop the pretest
ignition period, and repeat the draft determination procedure described
in section 8.2.
8.5 Velocity Measurements. During the pretest ignition period,
conduct a velocity traverse to identify the point of average velocity.
This single point shall be used for measuring velocity during the test
run.
[[Page 217]]
8.5.1 Velocity Traverse. Measure the diameter of the duct at the
velocity traverse port location through both ports. Calculate the duct
area using the average of the two diameters. A pretest leak-check of
pitot lines as in Method 2, section 8.1, is recommended. Place the
calibrated pitot tube at the centroid of the stack in either of the
velocity traverse ports. Adjust the damper or similar device on the
blower inlet until the velocity indicated by the pitot is approximately
220 m/min (720 ft/min). Continue to read the [Delta]p and temperature
until the velocity has remained constant (less than 5 percent change)
for 1 minute. Once a constant velocity is obtained at the centroid of
the duct, perform a velocity traverse as outlined in Method 2, section
8.3 using four points per traverse as outlined in Method 1. Measure the
[Delta]p and tunnel temperature at each traverse point and record the
readings. Calculate the total gas flow rate using calculations contained
in Method 2, section 12. Verify that the flow rate is 4 0.40 dscm/min (140 14 dscf/min);
if not, readjust the damper, and repeat the velocity traverse. The
moisture may be assumed to be 4 percent (100 percent relative humidity
at 85 [deg]F). Direct moisture measurements (e.g., according to Method
4) are also permissible.
Note: If burn rates exceed 3 kg/hr (6.6 lb/hr), dilution tunnel duct
flow rates greater than 4 dscm/min (140 dscfm) and sampling section duct
diameters larger than 150 mm (6 in.) are allowed. If larger ducts or
flow rates are used, the sampling section velocity shall be at least 220
m/min (720 fpm). In order to ensure measurable particulate mass catch,
it is recommended that the ratio of the average mass flow rate in the
dilution tunnel to the average fuel burn rate be less than 150:1 if
larger duct sizes or flow rates are used.
8.5.2 Testing Velocity Measurements. After obtaining velocity
traverse results that meet the flow rate requirements, choose a point of
average velocity and place the pitot and temperature sensor at that
location in the duct. Alternatively, locate the pitot and the
temperature sensor at the duct centroid and calculate a velocity
correction factor for the centroidal position. Mount the pitot to ensure
no movement during the test run and seal the port holes to prevent any
air leakage. Align the pitot opening to be parallel with the duct axis
at the measurement point. Check that this condition is maintained during
the test run (about 30-minute intervals). Monitor the temperature and
velocity during the pretest ignition period to ensure that the proper
flow rate is maintained. Make adjustments to the dilution tunnel flow
rate as necessary.
8.6 Pretest Preparation. Same as Method 5, section 8.1.
8.7 Preparation of Sampling Train. During preparation and assembly
of the sampling train, keep all openings where contamination can occur
covered until just prior to assembly or until sampling is about to
begin.
Using a tweezer or clean disposable surgical gloves, place one
labeled (identified) and weighed filter in each of the filter holders.
Be sure that each filter is properly centered and that the gasket is
properly placed so as to prevent the sample gas stream from
circumventing the filter. Check each filter for tears after assembly is
completed.
Mark the probe with heat resistant tape or by some other method to
denote the proper distance into the stack or duct. Set up the train as
shown in Figure 5G-1.
8.8 Leak-Check Procedures.
8.8.1 Leak-Check of Metering System Shown in Figure 5G-1. That
portion of the sampling train from the pump to the orifice meter shall
be leak-checked prior to initial use and after each certification or
audit test. Leakage after the pump will result in less volume being
recorded than is actually sampled. Use the procedure described in Method
5, section 8.4.1. Similar leak-checks shall be conducted for other types
of metering systems (i.e., without orifice meters).
8.8.2 Pretest Leak-Check. A pretest leak-check of the sampling train
is recommended, but not required. If the pretest leak check is
conducted, the procedures outlined in Method 5, section 8.4.2 should be
used. A vacuum of 130 mm Hg (5 in. Hg) may be used instead of 380 mm Hg
(15 in. Hg).
8.8.3 Post-Test Leak-Check. A leak-check of the sampling train is
mandatory at the conclusion of each test run. The leak-check shall be
performed in accordance with the procedures outlined in Method 5,
section 8.4.2. A vacuum of 130 mm Hg (5 in. Hg) or the highest vacuum
measured during the test run, whichever is greater, may be used instead
of 380 mm Hg (15 in. Hg).
8.9 Preliminary Determinations. Determine the pressure, temperature
and the average velocity of the tunnel gases as in section 8.5. Moisture
content of diluted tunnel gases is assumed to be 4 percent for making
flow rate calculations; the moisture content may be measured directly as
in Method 4.
8.10 Sampling Train Operation. Position the probe inlet at the stack
centroid, and block off the openings around the probe and porthole to
prevent unrepresentative dilution of the gas stream. Be careful not to
bump the probe into the stack wall when removing or inserting the probe
through the porthole; this minimizes the chance of extracting deposited
material.
8.10.1 Begin sampling at the start of the test run as defined in
Method 28, section 8.8.1. During the test run, maintain a sample flow
rate proportional to the dilution tunnel flow rate (within 10 percent of
the initial proportionality ratio) and a filter holder temperature of no
greater than 32 [deg]C (90 [deg]F).
[[Page 218]]
The initial sample flow rate shall be approximately 0.015 m\3\/min (0.5
cfm).
8.10.2 For each test run, record the data required on a data sheet
such as the one shown in Figure 5G-3. Be sure to record the initial dry
gas meter reading. Record the dry gas meter readings at the beginning
and end of each sampling time increment and when sampling is halted.
Take other readings as indicated on Figure 5G-3 at least once each 10
minutes during the test run. Since the manometer level and zero may
drift because of vibrations and temperature changes, make periodic
checks during the test run.
8.10.3 For the purposes of proportional sampling rate
determinations, data from calibrated flow rate devices, such as glass
rotameters, may be used in lieu of incremental dry gas meter readings.
Proportional rate calculation procedures must be revised, but
acceptability limits remain the same.
8.10.4 During the test run, make periodic adjustments to keep the
temperature between (or upstream of) the filters at the proper level. Do
not change sampling trains during the test run.
8.10.5 At the end of the test run (see Method 28, section 6.4.6),
turn off the coarse adjust valve, remove the probe from the stack, turn
off the pump, record the final dry gas meter reading, and conduct a
post-test leak-check, as outlined in section 8.8.2. Also, leak-check the
pitot lines as described in Method 2, section 8.1; the lines must pass
this leak-check in order to validate the velocity head data.
8.11 Calculation of Proportional Sampling Rate. Calculate percent
proportionality (see section 12.7) to determine whether the run was
valid or another test run should be made.
8.12 Sample Recovery. Same as Method 5, section 8.7, with the
exception of the following:
8.12.1 An acetone blank volume of about 50-ml or more may be used.
8.12.2 Treat the samples as follows:
8.12.2.1 Container Nos. 1 and 1A. Treat the two filters according to
the procedures outlined in Method 5, section 8.7.6.1. The filters may be
stored either in a single container or in separate containers. Use the
sum of the filter tare weights to determine the sample mass collected.
8.12.2.3 Container No. 2.
8.12.2.3.1 Taking care to see that dust on the outside of the probe
or other exterior surfaces does not get into the sample, quantitatively
recover particulate matter or any condensate from the probe and filter
holders by washing and brushing these components with acetone and
placing the wash in a labeled glass container. At least three cycles of
brushing and rinsing are required.
8.12.2.3.2 Between sampling runs, keep brushes clean and protected
from contamination.
8.12.2.3.3 After all acetone washings and particulate matter have
been collected in the sample containers, tighten the lids on the sample
containers so that the acetone will not leak out when transferred to the
laboratory weighing area. Mark the height of the fluid levels to
determine whether leakage occurs during transport. Label the containers
clearly to identify contents.
8.13 Sample Transport. Whenever possible, containers should be
shipped in such a way that they remain upright at all times.
Note: Requirements for capping and transport of sample containers
are not applicable if sample recovery and analysis occur in the same
room.
9.0 Quality Control
9.1 Miscellaneous Quality Control Measures.
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
8.8, 10.1-10.4................ Sampling Ensures accurate
equipment leak measurement of stack
check and gas flow rate,
calibration. sample volume.
10.5.......................... Analytical Ensure accurate and
balance precise measurement
calibration. of collected
particulate.
16.2.5........................ Simultaneous, Ensure precision of
dual-train measured particulate
sample concentration.
collection.
------------------------------------------------------------------------
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
10.0 Calibration and Standardization
Note: Maintain a laboratory record of all calibrations.
10.1 Pitot Tube. The Type S pitot tube assembly shall be calibrated
according to the procedure outlined in Method 2, section 10.1, prior to
the first certification test and checked semiannually, thereafter. A
standard pitot need not be calibrated but shall be inspected and
cleaned, if necessary, prior to each certification test.
10.2 Volume Metering System.
10.2.1 Initial and Periodic Calibration. Before its initial use and
at least semiannually thereafter, calibrate the volume metering system
as described in Method 5, section 10.3.1, except that the wet test meter
with a capacity of 3.0 liters/rev (0.1 ft\3\/rev) may be used. Other
liquid displacement systems accurate to within 1
percent, may be used as calibration standards.
[[Page 219]]
Note: Procedures and equipment specified in Method 5, section 16.0,
for alternative calibration standards, including calibrated dry gas
meters and critical orifices, are allowed for calibrating the dry gas
meter in the sampling train. A dry gas meter used as a calibration
standard shall be recalibrated at least once annually.
10.2.2 Calibration After Use. After each certification or audit test
(four or more test runs conducted on a wood heater at the four burn
rates specified in Method 28), check calibration of the metering system
by performing three calibration runs at a single, intermediate flow rate
as described in Method 5, section 10.3.2.
Note: Procedures and equipment specified in Method 5, section 16.0,
for alternative calibration standards are allowed for the post-test dry
gas meter calibration check.
10.2.3 Acceptable Variation in Calibration. If the dry gas meter
coefficient values obtained before and after a certification test differ
by more than 5 percent, the certification test shall either be voided
and repeated, or calculations for the certification test shall be
performed using whichever meter coefficient value (i.e., before or
after) gives the lower value of total sample volume.
10.3 Temperature Sensors. Use the procedure in Method 2, section
10.3, to calibrate temperature sensors before the first certification or
audit test and at least semiannually, thereafter.
10.4 Barometer. Calibrate against a mercury barometer before the
first certification test and at least semiannually, thereafter. If a
mercury barometer is used, no calibration is necessary. Follow the
manufacturer's instructions for operation.
10.5 Analytical Balance. Perform a multipoint calibration (at least
five points spanning the operational range) of the analytical balance
before the first certification test and semiannually, thereafter. Before
each certification test, audit the balance by weighing at least one
calibration weight (class F) that corresponds to 50 to 150 percent of
the weight of one filter. If the scale cannot reproduce the value of the
calibration weight to within 0.1 mg, conduct the multipoint calibration
before use.
11.0 Analytical Procedure
11.1 Record the data required on a sheet such as the one shown in
Figure 5G-4. Use the same analytical balance for determining tare
weights and final sample weights.
11.2 Handle each sample container as follows:
11.2.1 Container Nos. 1 and 1A. Treat the two filters according to
the procedures outlined in Method 5, section 11.2.1.
11.2.2 Container No. 2. Same as Method 5, section 11.2.2, except
that the beaker may be smaller than 250 ml.
11.2.3 Acetone Blank Container. Same as Method 5, section 11.2.4,
except that the beaker may be smaller than 250 ml.
12.0 Data Analysis and Calculations
Carry out calculations, retaining at least one extra significant
figure beyond that of the acquired data. Round off figures after the
final calculation. Other forms of the equations may be used as long as
they give equivalent results.
12.1 Nomenclature.
Bws = Water vapor in the gas stream, proportion by volume
(assumed to be 0.04).
cs = Concentration of particulate matter in stack gas, dry
basis, corrected to standard conditions, g/dscm (gr/dscf).
E = Particulate emission rate, g/hr (lb/hr).
Eadj = Adjusted particulate emission rate, g/hr (lb/hr).
La = Maximum acceptable leakage rate for either a pretest or
post-test leak-check, equal to 0.00057 m\3\/min (0.020 cfm) or
4 percent of the average sampling rate, whichever is less.
Lp = Leakage rate observed during the post-test leak-check,
m\3\/min (cfm).
ma = Mass of residue of acetone blank after evaporation, mg.
maw = Mass of residue from acetone wash after evaporation,
mg.
mn = Total amount of particulate matter collected, mg.
Mw = Molecular weight of water, 18.0 g/g-mole (18.0 lb/lb-
mole).
Pbar = Barometric pressure at the sampling site, mm Hg (in.
Hg).
PR = Percent of proportional sampling rate.
Ps = Absolute gas pressure in dilution tunnel, mm Hg (in.
Hg).
Pstd = Standard absolute pressure, 760 mm Hg (29.92 in. Hg).
Qsd = Average gas flow rate in dilution tunnel, calculated as
in Method 2, Equation 2-8, dscm/hr (dscf/hr).
Tm = Absolute average dry gas meter temperature (see Figure
5G-3), [deg]K ([deg]R).
Tmi = Absolute average dry gas meter temperature during each
10-minute interval, i, of the test run, [deg]K ([deg]R).
Ts = Absolute average gas temperature in the dilution tunnel
(see Figure 5G-3), [deg]K ([deg]R).
Tsi = Absolute average gas temperature in the dilution tunnel
during each 10 minute interval, i, of the test run, [deg]K
([deg]R).
Tstd = Standard absolute temperature, 293 [deg]K (528
[deg]R).
Va = Volume of acetone blank, ml.
Vaw = Volume of acetone used in wash, ml.
Vm = Volume of gas sample as measured by dry gas meter, dcm
(dcf).
[[Page 220]]
Vmi = Volume of gas sample as measured by dry gas meter
during each 10-minute interval, i, of the test run, dcm.
Vm(std) = Volume of gas sample measured by the dry gas meter,
corrected to standard conditions, dscm (dscf).
Vs = Average gas velocity in the dilution tunnel, calculated
by Method 2, Equation 2-7, m/sec (ft/sec). The dilution tunnel
dry gas molecular weight may be assumed to be 29 g/g mole (lb/
lb mole).
Vsi = Average gas velocity in dilution tunnel during each 10-
minute interval, i, of the test run, calculated by Method 2,
Equation 2-7, m/sec (ft/sec).
Y = Dry gas meter calibration factor.
[Delta]H = Average pressure differential across the orifice meter, if
used (see Figure 5G-2), mm H\2\O (in. H\2\O).
U = Total sampling time, min.
10 = 10 minutes, length of first sampling period.
13.6 = Specific gravity of mercury.
100 = Conversion to percent.
12.2 Dry Gas Volume. Same as Method 5, section 12.2, except that
component changes are not allowable.
12.3 Solvent Wash Blank.
[GRAPHIC] [TIFF OMITTED] TR17OC00.159
12.4 Total Particulate Weight. Determine the total particulate
catch, mn, from the sum of the weights obtained from Container Nos. 1,
1A, and 2, less the acetone blank (see Figure 5G-4).
12.5 Particulate Concentration.
[GRAPHIC] [TIFF OMITTED] TR17OC00.160
Where:
K2 = 0.001 g/mg for metric units.
= 0.0154 gr/mg for English units.
12.6 Particulate Emission Rate.
[GRAPHIC] [TIFF OMITTED] TR17OC00.161
Note: Particulate emission rate results produced using the sampling
train described in section 6 and shown in Figure 5G-1 shall be adjusted
for reporting purposes by the following method adjustment factor:
[GRAPHIC] [TIFF OMITTED] TR17OC00.162
Where:
K3 = constant, 1.82 for metric units.
= constant, 0.643 for English units.
12.7 Proportional Rate Variation. Calculate PR for each 10-minute
interval, i, of the test run.
[GRAPHIC] [TIFF OMITTED] TR17OC00.163
Alternate calculation procedures for proportional rate variation may
be used if other sample flow rate data (e.g., orifice flow meters or
rotameters) are monitored to maintain proportional sampling rates. The
proportional rate variations shall be calculated for each 10-minute
interval by comparing the stack to nozzle velocity ratio for each 10-
minute interval to the average stack to nozzle velocity ratio for the
test run. Proportional rate variation may be calculated for intervals
shorter than 10 minutes with appropriate revisions to Equation 5G-5. If
no more than 10 percent of the PR values for all the intervals exceed 90
percent <=PR <=110 percent, and if no PR value for any interval exceeds
80 percent <=PR <=120 percent, the results are acceptable. If the PR
values for the test run are judged to be unacceptable, report the test
run emission results, but do not include the results in calculating the
weighted average emission rate, and repeat the test run.
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Alternative Procedures
16.1 Method 5H Sampling Train. The sampling train and sample
collection, recovery, and analysis procedures described in Method 5H,
sections 6.1.1, 7.1, 7.2, 8.1, 8.10, 8.11, and 11.0, respectively, may
be used in lieu of similar sections in Method 5G. Operation of the
Method 5H sampling train in the dilution tunnel is as described in
section 8.10 of this method. Filter temperatures and condenser
conditions are as described in Method 5H. No adjustment to the measured
particulate matter emission rate (Equation 5G-4, section 12.6) is to be
applied to the particulate emission rate measured by this alternative
method.
16.2 Dual Sampling Trains. Two sampling trains may be operated
simultaneously at sample flow rates other than that specified
[[Page 221]]
in section 8.10, provided that the following specifications are met.
16.2.1 Sampling Train. The sampling train configuration shall be the
same as specified in section 6.1.1, except the probe, filter, and filter
holder need not be the same sizes as specified in the applicable
sections. Filter holders of plastic materials such as Nalgene or
polycarbonate materials may be used (the Gelman 1119 filter holder has
been found suitable for this purpose). With such materials, it is
recommended that solvents not be used in sample recovery. The filter
face velocity shall not exceed 150 mm/sec (30 ft/min) during the test
run. The dry gas meter shall be calibrated for the same flow rate range
as encountered during the test runs. Two separate, complete sampling
trains are required for each test run.
16.2.2 Probe Location. Locate the two probes in the dilution tunnel
at the same level (see section 6.1.4.3). Two sample ports are necessary.
Locate the probe inlets within the 50 mm (2 in.) diameter centroidal
area of the dilution tunnel no closer than 25 mm (1 in.) apart.
16.2.3 Sampling Train Operation. Operate the sampling trains as
specified in section 8.10, maintaining proportional sampling rates and
starting and stopping the two sampling trains simultaneously. The pitot
values as described in section 8.5.2 shall be used to adjust sampling
rates in both sampling trains.
16.2.4 Recovery and Analysis of Sample. Recover and analyze the
samples from the two sampling trains separately, as specified in
sections 8.12 and 11.0, respectively.
16.2.4.1 For this alternative procedure, the probe and filter holder
assembly may be weighed without sample recovery (use no solvents)
described above in order to determine the sample weight gains. For this
approach, weigh the clean, dry probe and filter holder assembly upstream
of the front filter (without filters) to the nearest 0.1 mg to establish
the tare weights. The filter holder section between the front and second
filter need not be weighed. At the end of the test run, carefully clean
the outside of the probe, cap the ends, and identify the sample (label).
Remove the filters from the filter holder assemblies as described for
container Nos. 1 and 1A in section 8.12.2.1. Reassemble the filter
holder assembly, cap the ends, identify the sample (label), and transfer
all the samples to the laboratory weighing area for final weighing.
Requirements for capping and transport of sample containers are not
applicable if sample recovery and analysis occur in the same room.
16.2.4.2 For this alternative procedure, filters may be weighed
directly without a petri dish. If the probe and filter holder assembly
are to be weighed to determine the sample weight, rinse the probe with
acetone to remove moisture before desiccating prior to the test run.
Following the test run, transport the probe and filter holder to the
desiccator, and uncap the openings of the probe and the filter holder
assembly. Desiccate for 24 hours and weigh to a constant weight. Report
the results to the nearest 0.1 mg.
16.2.5 Calculations. Calculate an emission rate (Section 12.6) for
the sample from each sampling train separately and determine the average
emission rate for the two values. The two emission rates shall not
differ by more than 7.5 percent from the average emission rate, or 7.5
percent of the weighted average emission rate limit in the applicable
subpart of the regulations, whichever is greater. If this specification
is not met, the results are unacceptable. Report the results, but do not
include the results in calculating the weighted average emission rate.
Repeat the test run until acceptable results are achieved, report the
average emission rate for the acceptable test run, and use the average
in calculating the weighted average emission rate.
17.0 References
Same as Method 5, section 17.0, References 1 through 11, with the
addition of the following:
1. Oregon Department of Environmental Quality. Standard Method for
Measuring the Emissions and Efficiencies of Woodstoves. June 8, 1984.
Pursuant to Oregon Administrative Rules Chapter 340, Division 21.
2. American Society for Testing and Materials. Proposed Test Methods
for Heating Performance and Emissions of Residential Wood-fired Closed
Combustion-Chamber Heating Appliances. E-6 Proposal P 180. August 1986.
18.0 Tables, Diagrams, Flowcharts, and Validation Data
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Method 5H--Determination of Particulate Matter Emissions From Wood
Heaters From a Stack Location
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 2, Method 3, Method 5,
Method 5G, Method 6, Method 6C, Method 16A, and Method 28.
1.0 Scope and Application
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
[[Page 226]]
1.2 Applicability. This method is applicable for the determination
of PM and condensible emissions from wood heaters.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 Particulate matter is withdrawn proportionally from the wood
heater exhaust and is collected on two glass fiber filters separated by
impingers immersed in an ice water bath. The first filter is maintained
at a temperature of no greater than 120 [deg]C (248 [deg]F). The second
filter and the impinger system are cooled such that the temperature of
the gas exiting the second filter is no greater than 20 [deg]C (68
[deg]F). The particulate mass collected in the probe, on the filters,
and in the impingers is determined gravimetrically after the removal of
uncombined water.
3.0 Definitions
Same as in Method 6C, section 3.0.
4.0 Interferences [Reserved]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and to determine the applicability of regulatory limitations
prior to performing this test method.
6.0 Equipment and Supplies
6.1 Sample Collection. The following items are required for sample
collection:
6.1.1 Sampling Train. The sampling train configuration is shown in
Figure 5H-1. Same as Method 5, section 6.1.1, with the exception of the
following:
6.1.1.1 Probe Nozzle. The nozzle is optional; a straight sampling
probe without a nozzle is an acceptable alternative.
6.1.1.2 Probe Liner. Same as Method 5, section 6.1.1.2, except that
the maximum length of the sample probe shall be 0.6 m (2 ft) and probe
heating is optional.
6.1.1.3 Filter Holders. Two each of borosilicate glass, with a glass
frit or stainless steel filter support and a silicone rubber, Teflon, or
Viton gasket. The holder design shall provide a positive seal against
leakage from the outside or around the filter. The front filter holder
shall be attached immediately at the outlet of the probe and prior to
the first impinger. The second filter holder shall be attached on the
outlet of the third impinger and prior to the inlet of the fourth
(silica gel) impinger.
6.1.2 Barometer. Same as Method 5, section 6.2.
6.1.3 Stack Gas Flow Rate Measurement System. A schematic of an
example test system is shown in Figure 5H-2. The flow rate measurement
system consists of the following components:
6.1.3.1 Sample Probe. A glass or stainless steel sampling probe.
6.1.3.2 Gas Conditioning System. A high density filter to remove
particulate matter and a condenser capable of lowering the dew point of
the gas to less than 5 [deg]C (40 [deg]F). Desiccant, such as Drierite,
may be used to dry the sample gas. Do not use silica gel.
6.1.3.3 Pump. An inert (e.g., Teflon or stainless steel heads)
sampling pump capable of delivering more than the total amount of sample
required in the manufacturer's instructions for the individual
instruments. A means of controlling the analyzer flow rate and a device
for determining proper sample flow rate (e.g., precision rotameter,
pressure gauge downstream of all flow controls) shall be provided at the
analyzer. The requirements for measuring and controlling the analyzer
flow rate are not applicable if data are presented that demonstrate that
the analyzer is insensitive to flow variations over the range
encountered during the test.
6.1.3.4 Carbon Monoxide (CO) Analyzer. Any analyzer capable of
providing a measure of CO in the range of 0 to 10 percent by volume at
least once every 10 minutes.
6.1.3.5 Carbon Dioxide (CO2) Analyzer. Any analyzer
capable of providing a measure of CO2 in the range of 0 to 25
percent by volume at least once every 10 minutes.
Note: Analyzers with ranges less than those specified above may be
used provided actual concentrations do not exceed the range of the
analyzer.
6.1.3.6 Manifold. A sampling tube capable of delivering the sample
gas to two analyzers and handling an excess of the total amount used by
the analyzers. The excess gas is exhausted through a separate port.
6.1.3.7 Recorders (optional). To provide a permanent record of the
analyzer outputs.
6.1.4 Proportional Gas Flow Rate System. To monitor stack flow rate
changes and provide a measurement that can be used to adjust and
maintain particulate sampling flow rates proportional to the stack gas
flow rate. A schematic of the proportional flow rate system is shown in
Figure 5H-2 and consists of the following components:
6.1.4.1 Tracer Gas Injection System. To inject a known concentration
of sulfur dioxide (SO2) into the flue. The tracer gas
injection system consists of a cylinder of SO2, a gas
cylinder regulator, a stainless steel needle valve or flow controller, a
nonreactive (stainless steel and glass) rotameter, and an injection loop
to disperse the SO2 evenly in the flue.
[[Page 227]]
6.1.4.2 Sample Probe. A glass or stainless steel sampling probe.
6.1.4.3 Gas Conditioning System. A combustor as described in Method
16A, sections 6.1.5 and 6.1.6, followed by a high density filter to
remove particulate matter, and a condenser capable of lowering the dew
point of the gas to less than 5 [deg]C (40 [deg]F). Desiccant, such as
Drierite, may be used to dry the sample gas. Do not use silica gel.
6.1.4.4 Pump. Same as described in section 6.1.3.3.
6.1.4.5 SO2 Analyzer. Any analyzer capable of providing a
measure of the SO2 concentration in the range of 0 to 1,000
ppm by volume (or other range necessary to measure the SO2
concentration) at least once every 10 minutes.
6.1.4.6 Recorder (optional). To provide a permanent record of the
analyzer outputs.
Note: Other tracer gas systems, including helium gas systems, are
acceptable for determination of instantaneous proportional sampling
rates.
6.2 Sample Recovery. Same as Method 5, section 6.2.
6.3 Sample Analysis. Same as Method 5, section 6.3, with the
addition of the following:
6.3.1 Separatory Funnel. Glass or Teflon, 500-ml or greater.
7.0 Reagents and Standards
7.1 Sample Collection. Same as Method 5, section 7.1, including
deionized distilled water.
7.2 Sample Recovery. Same as Method 5, section 7.2.
7.3 Sample Analysis. The following reagents and standards are
required for sample analysis:
7.3.1 Acetone. Same as Method 5 section 7.2.
7.3.2 Dichloromethane (Methylene Chloride). Reagent grade, <0.001
percent residue in glass bottles.
7.3.3 Desiccant. Anhydrous calcium sulfate, calcium chloride, or
silica gel, indicating type.
7.3.4 Cylinder Gases. For the purposes of this procedure, span value
is defined as the upper limit of the range specified for each analyzer
as described in section 6.1.3.4 or 6.1.3.5. If an analyzer with a range
different from that specified in this method is used, the span value
shall be equal to the upper limit of the range for the analyzer used
(see note in section 6.1.3.5).
7.3.4.1 Calibration Gases. The calibration gases for the
CO2, CO, and SO2 analyzers shall be CO2
in nitrogen (N2), CO in N2, and SO2 in
N2, respectively. CO2 and CO calibration gases may
be combined in a single cylinder. Use three calibration gases as
specified in Method 6C, sections 7.2.1 through 7.2.3.
7.3.4.2 SO2 Injection Gas. A known concentration of
SO2 in N2. The concentration must be at least 2
percent SO2 with a maximum of 100 percent SO2.
8.0 Sample Collection, Preservation, Transport, and Storage
8.1 Pretest Preparation. Same as Method 5, section 8.1.
8.2 Calibration Gas and SO2 Injection Gas Concentration
Verification, Sampling System Bias Check, Response Time Test, and Zero
and Calibration Drift Tests. Same as Method 6C, sections 8.2.1, 8.2.3,
8.2.4, and 8.5, respectively, except that for verification of CO and
CO2 gas concentrations, substitute Method 3 for Method 6.
8.3 Preliminary Determinations.
8.3.1 Sampling Location. The sampling location for the particulate
sampling probe shall be 2.45 0.15 m (8 0.5 ft) above the platform upon which the wood heater is
placed (i.e., the top of the scale).
8.3.2 Sampling Probe and Nozzle. Select a nozzle, if used, sized for
the range of velocity heads, such that it is not necessary to change the
nozzle size in order to maintain proportional sampling rates. During the
run, do not change the nozzle size. Select a suitable probe liner and
probe length to effect minimum blockage.
8.4 Preparation of Particulate Sampling Train. Same as Method 5,
section 8.3, with the exception of the following:
8.4.1 The train should be assembled as shown in Figure 5H-1.
8.4.2 A glass cyclone may not be used between the probe and filter
holder.
8.5 Leak-Check Procedures.
8.5.1 Leak-Check of Metering System Shown in Figure 5H-1. That
portion of the sampling train from the pump to the orifice meter shall
be leak-checked after each certification or audit test. Use the
procedure described in Method 5, section 8.4.1.
8.5.2 Pretest Leak-Check. A pretest leak-check of the sampling train
is recommended, but not required. If the pretest leak-check is
conducted, the procedures outlined in Method 5, section 8.5.2 should be
used. A vacuum of 130 mm Hg (5 in. Hg) may be used instead of 380 mm Hg
(15 in. Hg).
8.5.2 Leak-Checks During Sample Run. If, during the sampling run, a
component (e.g., filter assembly or impinger) change becomes necessary,
conduct a leak-check as described in Method 5, section 8.4.3.
8.5.3 Post-Test Leak-Check. A leak-check is mandatory at the
conclusion of each sampling run. The leak-check shall be performed in
accordance with the procedures outlined in Method 5, section 8.4.4,
except that a vacuum of 130 mm Hg (5 in. Hg) or the greatest vacuum
measured during the test run, whichever is greater, may be used instead
of 380 mm Hg (15 in. Hg).
[[Page 228]]
8.6 Tracer Gas Procedure. A schematic of the tracer gas injection
and sampling systems is shown in Figure 5H-2.
8.6.1 SO2 Injection Probe. Install the SO2
injection probe and dispersion loop in the stack at a location 2.9
0.15 m (9.5 0.5 ft) above
the sampling platform.
8.6.2 SO2 Sampling Probe. Install the SO2
sampling probe at the centroid of the stack at a location 4.1 0.15 m (13.5 0.5 ft) above the
sampling platform.
8.7 Flow Rate Measurement System. A schematic of the flow rate
measurement system is shown in Figure 5H-2. Locate the flow rate
measurement sampling probe at the centroid of the stack at a location
2.3 0.3 m (7.5 1 ft) above
the sampling platform.
8.8 Tracer Gas Procedure. Within 1 minute after closing the wood
heater door at the start of the test run (as defined in Method 28,
section 8.8.1), meter a known concentration of SO2 tracer gas
at a constant flow rate into the wood heater stack. Monitor the
SO2 concentration in the stack, and record the SO2
concentrations at 10-minute intervals or more often. Adjust the
particulate sampling flow rate proportionally to the SO2
concentration changes using Equation 5H-6 (e.g., the SO2
concentration at the first 10-minute reading is measured to be 100 ppm;
the next 10 minute SO2 concentration is measured to be 75
ppm: the particulate sample flow rate is adjusted from the initial 0.15
cfm to 0.20 cfm). A check for proportional rate variation shall be made
at the completion of the test run using Equation 5H-10.
8.9 Volumetric Flow Rate Procedure. Apply stoichiometric
relationships to the wood combustion process in determining the exhaust
gas flow rate as follows:
8.9.1 Test Fuel Charge Weight. Record the test fuel charge weight
(wet) as specified in Method 28, section 8.8.2. The wood is assumed to
have the following weight percent composition: 51 percent carbon, 7.3
percent hydrogen, 41 percent oxygen. Record the wood moisture for each
fuel charge as described in Method 28, section 8.6.5. The ash is assumed
to have negligible effect on associated C, H, and O concentrations after
the test burn.
8.9.2 Measured Values. Record the CO and CO2
concentrations in the stack on a dry basis every 10 minutes during the
test run or more often. Average these values for the test run. Use as a
mole fraction (e.g., 10 percent CO2 is recorded as 0.10) in
the calculations to express total flow (see Equation 5H-6).
8.10 Sampling Train Operation.
8.10.1 For each run, record the data required on a data sheet such
as the one shown in Figure 5H-3. Be sure to record the initial dry gas
meter reading. Record the dry gas meter readings at the beginning and
end of each sampling time increment, when changes in flow rates are
made, before and after each leak-check, and when sampling is halted.
Take other readings as indicated on Figure 5H-3 at least once each 10
minutes during the test run.
8.10.2 Remove the nozzle cap, verify that the filter and probe
heating systems are up to temperature, and that the probe is properly
positioned. Position the nozzle, if used, facing into gas stream, or the
probe tip in the 50 mm (2 in.) centroidal area of the stack.
8.10.3 Be careful not to bump the probe tip into the stack wall when
removing or inserting the probe through the porthole; this minimizes the
chance of extracting deposited material.
8.10.4 When the probe is in position, block off the openings around
the probe and porthole to prevent unrepresentative dilution of the gas
stream.
8.10.5 Begin sampling at the start of the test run as defined in
Method 28, section 8.8.1, start the sample pump, and adjust the sample
flow rate to between 0.003 and 0.014 m\3\/min (0.1 and 0.5 cfm). Adjust
the sample flow rate proportionally to the stack gas flow during the
test run according to the procedures outlined in section 8. Maintain a
proportional sampling rate (within 10 percent of the desired value) and
a filter holder temperature no greater than 120 [deg]C (248 [deg]F).
8.10.6 During the test run, make periodic adjustments to keep the
temperature around the filter holder at the proper level. Add more ice
to the impinger box and, if necessary, salt to maintain a temperature of
less than 20 [deg]C (68 [deg]F) at the condenser/silica gel outlet.
8.10.7 If the pressure drop across the filter becomes too high,
making proportional sampling difficult to maintain, either filter may be
replaced during a sample run. It is recommended that another complete
filter assembly be used rather than attempting to change the filter
itself. Before a new filter assembly is installed, conduct a leak-check
(see section 8.5.2). The total particulate weight shall include the
summation of all filter assembly catches. The total time for changing
sample train components shall not exceed 10 minutes. No more than one
component change is allowed for any test run.
8.10.8 At the end of the test run, turn off the coarse adjust valve,
remove the probe and nozzle from the stack, turn off the pump, record
the final dry gas meter reading, and conduct a post-test leak-check, as
outlined in section 8.5.3.
8.11 Sample Recovery. Same as Method 5, section 8.7, with the
exception of the following:
8.11.1 Blanks. The volume of the acetone blank may be about 50-ml,
rather than 200-ml; a 200-ml water blank shall also be saved for
analysis.
8.11.2 Samples.
8.11.2.1 Container Nos. 1 and 1A. Treat the two filters according to
the procedures outlined in Method 5, section 8.7.6.1. The filters
[[Page 229]]
may be stored either in a single container or in separate containers.
8.11.2.2 Container No. 2. Same as Method 5, section 8.7.6.2, except
that the container should not be sealed until the impinger rinse
solution is added (see section 8.10.2.4).
8.11.2.3 Container No. 3. Treat the impingers as follows: Measure
the liquid which is in the first three impingers to within 1-ml by using
a graduated cylinder or by weighing it to within 0.5 g by using a
balance (if one is available). Record the volume or weight of liquid
present. This information is required to calculate the moisture content
of the effluent gas. Transfer the water from the first, second, and
third impingers to a glass container. Tighten the lid on the sample
container so that water will not leak out.
8.11.2.4 Rinse impingers and graduated cylinder, if used, with
acetone three times or more. Avoid direct contact between the acetone
and any stopcock grease or collection of any stopcock grease in the
rinse solutions. Add these rinse solutions to sample Container No. 2.
8.11.2.5 Container No. 4. Same as Method 5, section 8.7.6.3
8.12 Sample Transport. Whenever possible, containers should be
transferred in such a way that they remain upright at all times.
Note: Requirements for capping and transport of sample containers
are not applicable if sample recovery and analysis occur in the same
room.
9.0 Quality Control
9.1 Miscellaneous Quality Control Measures.
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
8.2........................... Sampling system Ensures that bias
bias check. introduced by
measurement system,
minus analyzer, is
no greater than 3
percent of span.
8.2........................... Analyzer zero and Ensures that bias
calibration introduced by drift
drift tests. in the measurement
system output during
the run is no
greater than 3
percent of span.
8.5, 10.1, 12.13.............. Sampling Ensures accurate
equipment leak- measurement of stack
check and gas flow rate,
calibration; sample volume.
proportional
sampling rate
verification.
10.1.......................... Analytical Ensure accurate and
balance precise measurement
calibration. of collected
particulate.
10.3.......................... Analyzer Ensures that bias
calibration introduced by
error check. analyzer calibration
error is no greater
than 2 percent of
span.
------------------------------------------------------------------------
9.2 Volume Metering System Checks. Same as Method 5, section 9.2.
10.0 Calibration and Standardization
Note: Maintain a laboratory record of all calibrations.
10.1 Volume Metering System, Temperature Sensors, Barometer, and
Analytical Balance. Same as Method 5G, sections 10.2 through 10.5,
respectively.
10.2 SO2 Injection Rotameter. Calibrate the
SO2 injection rotameter system with a soap film flowmeter or
similar direct volume measuring device with an accuracy of 2 percent.
Operate the rotameter at a single reading for at least three calibration
runs for 10 minutes each. When three consecutive calibration flow rates
agree within 5 percent, average the three flow rates, mark the rotameter
at the calibrated setting, and use the calibration flow rate as the
SO2 injection flow rate during the test run. Repeat the
rotameter calibration before the first certification test and
semiannually thereafter.
10.3. Gas Analyzers. Same as Method 6C, section 10.0.
10.4 Field Balance Calibration Check. Check the calibration of the
balance used to weigh impingers with a weight that is at least 500g or
within 50g of a loaded impinger. The weight must be ASTM E617-13
``Standard Specification for Laboratory Weights and Precision Mass
Standards'' (incorporated by reference--see 40 CFR 60.17) Class 6 (or
better). Daily before use, the field balance must measure the weight
within 0.5g of the certified mass. If the daily
balance calibration check fails, perform corrective measures and repeat
the check before using balance.
10.5 Analytical Balance Calibration. Perform a multipoint
calibration (at least five points spanning the operational range) of the
analytical balance before the first use, and semiannually thereafter.
The calibration of the analytical balance must be conducted using ASTM
E617-13 ``Standard Specification for Laboratory Weights and Precision
Mass Standards'' (incorporated by reference--see 40 CFR 60.17) Class 2
(or better) tolerance weights. Audit the balance each day it is used for
gravimetric measurements by weighing at least one ASTM E617-13 Class 2
tolerance (or better) calibration weight that corresponds to 50 to 150
percent of the weight of one filter or between 1g and 5g. If the scale
cannot reproduce the value of the calibration weight to within 0.5 mg of
the certified mass, perform corrective measures, and conduct the
multipoint calibration before use.
[[Page 230]]
11.0 Analytical Procedure
11.1 Record the data required on a sheet such as the one shown in
Figure 5H-4.
11.2 Handle each sample container as follows:
11.2.1 Container Nos. 1 and 1A. Treat the two filters according to
the procedures outlined in Method 5, section 11.2.1.
11.2.2 Container No. 2. Same as Method 5, section 11.2.2, except
that the beaker may be smaller than 250-ml.
11.2.3 Container No. 3. Note the level of liquid in the container
and confirm on the analysis sheet whether leakage occurred during
transport. If a noticeable amount of leakage has occurred, either void
the sample or use methods, subject to the approval of the Administrator,
to correct the final results. Determination of sample leakage is not
applicable if sample recovery and analysis occur in the same room.
Measure the liquid in this container either volumetrically to within 1-
ml or gravimetrically to within 0.5 g. Transfer the contents to a 500-ml
or larger separatory funnel. Rinse the container with water, and add to
the separatory funnel. Add 25-ml of dichloromethane to the separatory
funnel, stopper and vigorously shake 1 minute, let separate and transfer
the dichloromethane (lower layer) into a tared beaker or evaporating
dish. Repeat twice more. It is necessary to rinse Container No. 3 with
dichloromethane. This rinse is added to the impinger extract container.
Transfer the remaining water from the separatory funnel to a tared
beaker or evaporating dish and evaporate to dryness at 104 [deg]C (220
[deg]F). Desiccate and weigh to a constant weight. Evaporate the
combined impinger water extracts at ambient temperature and pressure.
Desiccate and weigh to a constant weight. Report both results to the
nearest 0.1 mg.
11.2.4 Container No. 4. Weigh the spent silica gel (or silica gel
plus impinger) to the nearest 0.5 g using a balance.
11.2.5 Acetone Blank Container. Same as Method 5, section 11.2.4,
except that the beaker may be smaller than 250 ml.
11.2.6 Dichloromethane Blank Container. Treat the same as the
acetone blank.
11.2.7 Water Blank Container. Transfer the water to a tared 250 ml
beaker and evaporate to dryness at 104 [deg]C (220 [deg]F). Desiccate
and weigh to a constant weight.
12.0 Data Analysis and Calculations
Carry out calculations, retaining at least one extra significant
figure beyond that of the acquired data. Round off figures after the
final calculation. Other forms of the equations may be used as long as
they give equivalent results.
12.1 Nomenclature.
A = Sample flow rate adjustment factor.
BR = Dry wood burn rate, kg/hr (lb/hr), from Method 28, Section 8.3.
Bws = Water vapor in the gas stream, proportion by volume.
Ci = Tracer gas concentration at inlet, ppmv.
Co = Tracer gas concentration at outlet, ppmv.
Cs = Concentration of particulate matter in stack gas, dry
basis, corrected to standard conditions, g/dscm (g/dscf).
E = Particulate emission rate, g/hr (lb/hr).
[Delta]H = Average pressure differential across the orifice meter (see
Figure 5H-1), mm H2O (in. H2O).
La = Maximum acceptable leakage rate for either a post-test
leak-check or for a leak-check following a component change;
equal to 0.00057 cmm (0.020 cfm) or 4 percent of the average
sampling rate, whichever is less.
L1 = Individual leakage rate observed during the leak-check
conducted before a component change, cmm (cfm).
Lp = Leakage rate observed during the post-test leak-check,
cmm (cfm).
mn = Total amount of particulate matter collected, mg.
Ma = Mass of residue of solvent after evaporation, mg.
NC = Grams of carbon/gram of dry fuel (lb/lb), equal to
0.0425.
NT = Total dry moles of exhaust gas/kg of dry wood burned, g-
moles/kg (lb-moles/lb).
PR = Percent of proportional sampling rate.
Pbar = Barometric pressure at the sampling site, mm Hg
(in.Hg).
Pstd = Standard absolute pressure, 760 mm Hg (29.92 in.Hg).
Qi = Gas volumetric flow rate at inlet, cfm (l/min).
Qo = Gas volumetric flow rate at outlet, cfm (l/min).
12.2 Average Dry Gas Meter Temperature and Average Orifice Pressure
Drop. See data sheet (Figure 5H-3).
12.3 Dry Gas Volume. Same as Method 5, section 12.3.
12.4 Volume of Water Vapor.
[GRAPHIC] [TIFF OMITTED] TR17OC00.168
Where:
K2 = 0.001333 m\3\/ml for metric units.
K2 = 0.04707 ft\3\/ml for English units.
12.5 Moisture Content.
[GRAPHIC] [TIFF OMITTED] TR17OC00.169
12.6 Solvent Wash Blank.
[GRAPHIC] [TIFF OMITTED] TR17OC00.170
12.7 Total Particulate Weight. Determine the total particulate catch
from the sum of the weights obtained from containers 1, 2, 3,
[[Page 231]]
and 4 less the appropriate solvent blanks (see Figure 5H-4).
Note: Refer to Method 5, section 8.5 to assist in calculation of
results involving two filter assemblies.
12.8 Particulate Concentration.
[GRAPHIC] [TIFF OMITTED] TR17OC00.171
12.9 Sample Flow Rate Adjustment.
[GRAPHIC] [TIFF OMITTED] TR17OC00.172
12.10 Carbon Balance for Total Moles of Exhaust Gas (dry)/kg of Wood
Burned in the Exhaust Gas.
[GRAPHIC] [TIFF OMITTED] TR17OC00.173
Where:
K3 = 1000 g/kg for metric units.
K3 = 1.0 lb/lb for English units.
Note: The NOX/SOX portion of the gas is
assumed to be negligible.
12.11 Total Stack Gas Flow Rate.
[GRAPHIC] [TIFF OMITTED] TR17OC00.174
Where:
K4 = 0.02406 dscm/g-mole for metric units.
K4 = 384.8 dscf/lb-mole for English units.
12.12 Particulate Emission Rate.
[GRAPHIC] [TIFF OMITTED] TR17OC00.175
12.13 Proportional Rate Variation. Calculate PR for each 10-minute
interval, i, of the test run.
[GRAPHIC] [TIFF OMITTED] TR17OC00.176
12.14 Acceptable Results. If no more than 15 percent of the PR
values for all the intervals fall outside the range 90 percent <=PR
<=110 percent, and if no PR value for any interval falls outside the
range 75 <=PR <=125 percent, the results are acceptable. If the PR
values for the test runs are judged to be unacceptable, report the test
run emission results, but do not include the test run results in
calculating the weighted average emission rate, and repeat the test.
12.15 Alternative Tracer Gas Flow Rate Determination.
[GRAPHIC] [TIFF OMITTED] TR27FE14.014
Note: This gives Q for a single instance only. Repeated multiple
determinations are needed to track temporal variations. Very small
variations in Qi, Ci, or Co may give
very large variations in Qo.
13.0 Method Performance [Reserved]
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Alternative Procedures
16.1 Alternative Stack Gas Volumetric Flow Rate Determination
(Tracer Gas).
16.1.1 Apparatus.
16.1.1.1 Tracer Gas Injector System. This is to inject a known
concentration of tracer gas into the stack. This system consists of a
cylinder of tracer gas, a gas cylinder regulator, a stainless steel
needle valve or a flow controller, a nonreactive (stainless steel or
glass) rotameter, and an injection loop to disperse the tracer gas
evenly in the stack.
16.1.1.2 Tracer Gas Probe. A glass or stainless steel sampling
probe.
16.1.1.3 Gas Conditioning System. A gas conditioning system is
suitable for delivering a cleaned sample to the analyzer consisting of a
filter to remove particulate and a condenser capable of lowering the dew
point of the sample gas to less than 5 [deg]C (40 [deg]F). A desiccant
such as anhydrous calcium sulfate may be used to dry the sample gas.
Desiccants which react or absorb tracer gas or stack gas may not be
used, e.g. silica gel absorbs CO2.
16.1.1.4 Pump. An inert (i.e., stainless steel or Teflon head) pump
to deliver more than the total sample required by the manufacturer's
specifications for the analyzer used to measure the downstream tracer
gas concentration.
16.1.1.5 Gas Analyzer. A gas analyzer is any analyzer capable of
measuring the tracer gas concentration in the range necessary at least
every 10 minutes. A means of controlling the analyzer flow rate and a
device for determining proper sample flow rate shall be provided unless
data is provided to show that the analyzer is insensitive to flow
variations over the range encountered during the test.
[[Page 232]]
The gas analyzer needs to meet or exceed the following performance
specifications:
------------------------------------------------------------------------
------------------------------------------------------------------------
Linearity....................... 1 percent of
full scale.
Calibration Error............... <=2 percent of span.
Response Time................... <=10 seconds.
Zero Drift (24 hour)............ <=2 percent of full scale.
Span Drift (24 hour)............ <=2 percent of full scale.
Resolution...................... <=0.5 percent of span.
------------------------------------------------------------------------
16.1.1.6 Recorder (optional). To provide a permanent record of the
analyzer output.
16.1.2 Reagents.
16.1.2.1 Tracer Gas. The tracer gas is sulfur hexafluoride in an
appropriate concentration for accurate analyzer measurement or pure
sulfur dioxide. The gas used must be nonreactive with the stack effluent
and give minimal (<3 percent) interference to measurement by the gas
analyzer.
16.1.3 Procedure. Select upstream and downstream locations in the
stack or duct for introducing the tracer gas and delivering the sampled
gas to the analyzer. The inlet location should be 8 or more duct
diameters beyond any upstream flow disturbance. The outlet should be 8
or more undisturbed duct diameters from the inlet and 2 or more duct
diameters from the duct exit. After installing the apparatus, meter a
known concentration of the tracer gas into the stack at the inlet
location. Use the gas sample probe and analyzer to show that no
stratification of the tracer gas is found in the stack at the
measurement locations. Monitor the tracer gas concentration from the
outlet location and record the concentration at 10-minute intervals or
more often at the option of the tester. A minimum of three measured
intervals is recommended to determine the stack gas volumetric flow
rate. Other statistical procedures may be applied for complete flow
characterization and additional QA/QC.
17.0 References
Same as Method 5G, section 17.0.
18.0 Tables, Diagrams, Flowcharts, and Validation Data
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[GRAPHIC] [TIFF OMITTED] TR17OC00.178
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Method 5I--Determination of Low Level Particulate Matter Emissions From
Stationary Sources
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Certain information is contained in other
EPA procedures found in this part. Therefore, to obtain reliable
results, persons using this method should have experience with and a
thorough knowledge of the following Methods: Methods 1, 2, 3, 4 and 5.
1. Scope and Application.
1.1 Analyte. Particulate matter (PM). No CAS number assigned.
[[Page 237]]
1.2 Applicability. This method is applicable for the determination
of low level particulate matter (PM) emissions from stationary sources.
The method is most effective for total PM catches of 50 mg or less. This
method was initially developed for performing correlation of manual PM
measurements to PM continuous emission monitoring systems (CEMS),
however it is also useful for other low particulate concentration
applications.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods. Method 5I requires the use of paired trains.
Acceptance criteria for the identification of data quality outliers from
the paired trains are provided in section 12.2 of this Method.
2. Summary of Method.
2.1. Description. The system setup and operation is essentially
identical to Method 5. Particulate is withdrawn isokinetically from the
source and collected on a 47 mm glass fiber filter maintained at a
temperature of 120 14 [deg]C (248 25 [deg]F). The PM mass is determined by gravimetric
analysis after the removal of uncombined water. Specific measures in
this procedure designed to improve system performance at low particulate
levels include:
1. Improved sample handling procedures
2 Light weight sample filter assembly
3. Use of low residue grade acetone
Accuracy is improved through the minimization of systemic errors
associated with sample handling and weighing procedures. High purity
reagents, all glass, grease free, sample train components, and light
weight filter assemblies and beakers, each contribute to the overall
objective of improved precision and accuracy at low particulate
concentrations.
2.2 Paired Trains. This method must be performed using a paired
train configuration. These trains may be operated as co-located trains
(to trains operating collecting from one port) or as simultaneous trains
(separate trains operating from different ports at the same time).
Procedures for calculating precision of the paired trains are provided
in section 12.
2.3 Detection Limit. a. Typical detection limit for manual
particulate testing is 0.5 mg. This mass is also cited as the accepted
weight variability limit in determination of ``constant weight'' as
cited in section 8.1.2 of this Method. EPA has performed studies to
provide guidance on minimum PM catch. The minimum detection limit (MDL)
is the minimum concentration or amount of an analyte that can be
determined with a specified degree of confidence to be different from
zero. We have defined the minimum or target catch as a concentration or
amount sufficiently larger than the MDL to ensure that the results are
reliable and repeatable. The particulate matter catch is the product of
the average particulate matter concentration on a mass per volume basis
and the volume of gas collected by the sample train. The tester can
generally control the volume of gas collected by increasing the sampling
time or to a lesser extent by increasing the rate at which sample is
collected. If the tester has a reasonable estimate of the PM
concentration from the source, the tester can ensure that the target
catch is collected by sampling the appropriate gas volume.
b. However, if the source has a very low particulate matter
concentration in the stack, the volume of gas sampled may need to be
very large which leads to unacceptably long sampling times. When
determining compliance with an emission limit, EPA guidance has been
that the tester does not always have to collect the target catch.
Instead, we have suggested that the tester sample enough stack gas, that
if the source were exactly at the level of the emission standard, the
sample catch would equal the target catch. Thus, if at the end of the
test the catch were smaller than the target, we could still conclude
that the source is in compliance though we might not know the exact
emission level. This volume of gas becomes a target volume that can be
translated into a target sampling time by assuming an average sampling
rate. Because the MDL forms the basis for our guidance on target
sampling times, EPA has conducted a systematic laboratory study to
define what is the MDL for Method 5 and determined the Method to have a
calculated practical quantitation limit (PQL) of 3 mg of PM and an MDL
of 1 mg.
c. Based on these results, the EPA has concluded that for PM
testing, the target catch must be no less than 3 mg. Those sample
catches between 1 mg and 3 mg are between the detection limit and the
limit of quantitation. If a tester uses the target catch to estimate a
target sampling time that results in sample catches that are less than 3
mg, you should not automatically reject the results. If the tester
calculated the target sampling time as described above by assuming that
the source was at the level of the emission limit, the results would
still be valid for determining that the source was in compliance. For
purposes other than determining compliance, results should be divided
into two categories--those that fall between 3 mg and 1 mg and those
that are below 1 mg. A sample catch between 1 and 3 mg may be used for
such purposes as calculating emission rates with the understanding that
the resulting emission rates can have a high degree of uncertainty.
Results of less than 1 mg should not be used for calculating emission
rates or pollutant concentrations.
d. When collecting small catches such as 3 mg, bias becomes an
important issue. Source testers must use extreme caution to reach the
PQL of 3 mg by assuring that sampling
[[Page 238]]
probes are very clean (perhaps confirmed by low blank weights) before
use in the field. They should also use low tare weight sample
containers, and establish a well-controlled balance room to weigh the
samples.
3. Definitions.
3.1 Light Weight Filter Housing. A smaller housing that allows the
entire filtering system to be weighed before and after sample
collection. (See. 6.1.3)
3.2 Paired Train. Sample systems trains may be operated as co-
located trains (two sample probes attached to each other in the same
port) or as simultaneous trains (two separate trains operating from
different ports at the same time).
4. Interferences.
a. There are numerous potential interferents that may be encountered
during performance of Method 5I sampling and analyses. This Method
should be considered more sensitive to the normal interferents typically
encountered during particulate testing because of the low level
concentrations of the flue gas stream being sampled.
b. Care must be taken to minimize field contamination, especially to
the filter housing since the entire unit is weighed (not just the filter
media). Care must also be taken to ensure that no sample is lost during
the sampling process (such as during port changes, removal of the filter
assemblies from the probes, etc.).
c. Balance room conditions are a source of concern for analysis of
the low level samples. Relative humidity, ambient temperatures
variations, air draft, vibrations and even barometric pressure can
affect consistent reproducible measurements of the sample media.
Ideally, the same analyst who performs the tare weights should perform
the final weights to minimize the effects of procedural differences
specific to the analysts.
d. Attention must also be provided to weighing artifacts caused by
electrostatic charges which may have to be discharged or neutralized
prior to sample analysis. Static charge can affect consistent and
reliable gravimetric readings in low humidity environments. Method 5I
recommends a relative humidity of less than 50 percent in the weighing
room environment used for sample analyses. However, lower humidity may
be encountered or required to address sample precision problems. Low
humidity conditions can increase the effects of static charge.
e. Other interferences associated with typical Method 5 testing
(sulfates, acid gases, etc.) are also applicable to Method 5I.
5. Safety.
Disclaimer. This method may involve hazardous materials, operations,
and equipment. This test method may not address all of the safety
concerns associated with its use. It is the responsibility of the user
to establish appropriate safety and health practices and to determine
the applicability and observe all regulatory limitations before using
this method.
6. Equipment and Supplies.
6.1 Sample Collection Equipment and Supplies. The sample train is
nearly identical in configuration to the train depicted in Figure 5-1 of
Method 5. The primary difference in the sample trains is the lightweight
Method 5I filter assembly that attaches directly to the exit to the
probe. Other exceptions and additions specific to Method 5I include:
6.1.1 Probe Nozzle. Same as Method 5, with the exception that it
must be constructed of borosilicate or quartz glass tubing.
6.1.2 Probe Liner. Same as Method 5, with the exception that it must
be constructed of borosilicate or quartz glass tubing.
6.1.3 Filter Holder. The filter holder is constructed of
borosilicate or quartz glass front cover designed to hold a 47-mm glass
fiber filter, with a wafer thin stainless steel (SS) filter support, a
silicone rubber or Viton O-ring, and Teflon tape seal. This holder
design will provide a positive seal against leakage from the outside or
around the filter. The filter holder assembly fits into a SS filter
holder and attaches directly to the outlet of the probe. The tare weight
of the filter, borosilicate or quartz glass holder, SS filter support,
O-ring and Teflon tape seal generally will not exceed approximately 35
grams. The filter holder is designed to use a 47-mm glass fiber filter
meeting the quality criteria in of Method 5. These units are
commercially available from several source testing equipment vendors.
Once the filter holder has been assembled, desiccated and tared, protect
it from external sources of contamination by covering the front socket
with a ground glass plug. Secure the plug with an impinger clamp or
other item that will ensure a leak-free fitting.
6.2 Sample Recovery Equipment and Supplies. Same as Method 5, with
the following exceptions:
6.2.1 Probe-Liner and Probe-Nozzle Brushes. Teflon or nylon bristle
brushes with stainless steel wire handles, should be used to clean the
probe. The probe brush must have extensions (at least as long as the
probe) of Teflon, nylon or similarly inert material. The brushes must be
properly sized and shaped for brushing out the probe liner and nozzle.
6.2.2 Wash Bottles. Two Teflon wash bottles are recommended however,
polyethylene wash bottles may be used at the option of the tester.
Acetone should not be stored in polyethylene bottles for longer than one
month.
[[Page 239]]
6.2.3 Filter Assembly Transport. A system should be employed to
minimize contamination of the filter assemblies during transport to and
from the field test location. A carrying case or packet with clean
compartments of sufficient size to accommodate each filter assembly can
be used. This system should have an air tight seal to further minimize
contamination during transport to and from the field.
6.3 Analysis Equipment and Supplies. Same as Method 5, with the
following exception:
6.3.1 Lightweight Beaker Liner. Teflon or other lightweight beaker
liners are used for the analysis of the probe and nozzle rinses. These
light weight liners are used in place of the borosilicate glass beakers
typically used for the Method 5 weighings in order to improve sample
analytical precision.
6.3.2 Anti-static Treatment. Commercially available gaseous anti-
static rinses are recommended for low humidity situations that
contribute to static charge problems.
7. Reagents and Standards.
7.1 Sampling Reagents. The reagents used in sampling are the same as
Method 5 with the following exceptions:
7.1.1 Filters. The quality specifications for the filters are
identical to those cited for Method 5. The only difference is the filter
diameter of 47 millimeters.
7.1.2 Stopcock Grease. Stopcock grease cannot be used with this
sampling train. We recommend that the sampling train be assembled with
glass joints containing O-ring seals or screw-on connectors, or similar.
7.1.3 Acetone. Low residue type acetone, <=0.001 percent residue,
purchased in glass bottles is used for the recovery of particulate
matter from the probe and nozzle. Acetone from metal containers
generally has a high residue blank and should not be used. Sometimes,
suppliers transfer acetone to glass bottles from metal containers; thus,
acetone blanks must be run prior to field use and only acetone with low
blank values (<=0.001 percent residue, as specified by the manufacturer)
must be used. Acetone blank correction is not allowed for this method;
therefore, it is critical that high purity reagents be purchased and
verified prior to use.
7.1.4 Gloves. Disposable, powder-free, latex surgical gloves, or
their equivalent are used at all times when handling the filter housings
or performing sample recovery.
7.2 Standards. There are no applicable standards commercially
available for Method 5I analyses.
8. Sample Collection, Preservation, Storage, and Transport.
8.1 Pretest Preparation. Same as Method 5 with several exceptions
specific to filter assembly and weighing.
8.1.1 Filter Assembly. Uniquely identify each filter support before
loading filters into the holder assembly. This can be done with an
engraving tool or a permanent marker. Use powder free latex surgical
gloves whenever handling the filter holder assemblies. Place the O-ring
on the back of the filter housing in the O-ring groove. Place a 47 mm
glass fiber filter on the O-ring with the face down. Place a stainless
steel filter holder against the back of the filter. Carefully wrap 5 mm
(\1/4\ inch) wide Teflon'' tape one timearound the outside of the filter
holder overlapping the stainless steel filter support by approximately
2.5 mm (\1/8\ inch). Gently brush the Teflon tape down on the back of
the stainless steel filter support. Store the filter assemblies in their
transport case until time for weighing or field use.
8.1.2 Filter Weighing Procedures. a. Desiccate the entire filter
holder assemblies at 20 5.6 [deg]C (68 10 [deg]F) and ambient pressure for at least 24 hours.
Weigh at intervals of at least 6 hours to a constant weight, i.e., 0.5
mg change from previous weighing. Record the results to the nearest 0.1
mg. During each weighing, the filter holder assemblies must not be
exposed to the laboratory atmosphere for a period greater than 2 minutes
and a relative humidity above 50 percent. Lower relative humidity may be
required in order to improve analytical precision. However, low humidity
conditions increase static charge to the sample media.
b. Alternatively (unless otherwise specified by the Administrator),
the filters holder assemblies may be oven dried at 105 [deg]C (220
[deg]F) for a minimum of 2 hours, desiccated for 2 hours, and weighed.
The procedure used for the tare weigh must also be used for the final
weight determination.
c. Experience has shown that weighing uncertainties are not only
related to the balance performance but to the entire weighing procedure.
Therefore, before performing any measurement, establish and follow
standard operating procedures, taking into account the sampling
equipment and filters to be used.
8.2 Preliminary Determinations. Select the sampling site, traverse
points, probe nozzle, and probe length as specified in Method 5.
8.3 Preparation of Sampling Train. Same as Method 5, section 8.3,
with the following exception: During preparation and assembly of the
sampling train, keep all openings where contamination can occur covered
until justbefore assembly or until sampling is about to begin. Using
gloves, place a labeled (identified) and weighed filter holder assembly
into the stainless steel holder. Then place this whole unit in the
Method 5 hot box, and attach it to the probe. Do not use stopcock
grease.
8.4 Leak-Check Procedures. Same as Method 5.
8.5 Sampling Train Operation.
[[Page 240]]
8.5.1. Operation. Operate the sampling train in a manner consistent
with those described in Methods 1, 2, 4 and 5 in terms of the number of
sample points and minimum time per point. The sample rate and total gas
volume should be adjusted based on estimated grain loading of the source
being characterized. The total sampling time must be a function of the
estimated mass of particulate to be collected for the run. Targeted mass
to be collected in a typical Method 5I sample train should be on the
order of 10 to 20 mg. Method 5I is most appropriate for total collected
masses of less than 50 milligrams, however, there is not an exact
particulate loading cutoff, and it is likely that some runs may exceed
50 mg. Exceeding 50 mg (or less than 10 mg) for the sample mass does not
necessarily justify invalidating a sample run if all other Method
criteria are met.
8.5.2 Paired Train. This Method requires PM samples be collected
with paired trains.
8.5.2.1 It is important that the systems be operated truly
simultaneously. This implies that both sample systems start and stop at
the same times. This also means that if one sample system is stopped
during the run, the other sample systems must also be stopped until the
cause has been corrected.
8.5.2.2 Care should be taken to maintain the filter box temperature
of the paired trains as close as possible to the Method required
temperature of 120 14 [deg]C (248 25 [deg]F). If separate ovens are being used for
simultaneously operated trains, it is recommended that the oven
temperature of each train be maintained within 14
[deg]C (25 [deg]F) of each other.
8.5.2.3 The nozzles for paired trains need not be identically sized.
8.5.2.4 Co-located sample nozzles must be within the same plane
perpendicular to the gas flow. Co-located nozzles and pitot assemblies
should be within a 6.0 cm x 6.0 cm square (as cited for a quadruple
train in Reference Method 301).
8.5.3 Duplicate gas samples for molecular weight determination need
not be collected.
8.6 Sample Recovery. Same as Method 5 with several exceptions
specific to the filter housing.
8.6.1 Before moving the sampling train to the cleanup site, remove
the probe from the train and seal the nozzle inlet and outlet of the
probe. Be careful not to lose any condensate that might be present. Cap
the filter inlet using a standard ground glass plug and secure the cap
with an impinger clamp. Remove the umbilical cord from the last impinger
and cap the impinger. If a flexible line is used between the first
impinger condenser and the filter holder, disconnect the line at the
filter holder and let any condensed water or liquid drain into the
impingers or condenser.
8.6.2 Transfer the probe and filter-impinger assembly to the cleanup
area. This area must be clean and protected from the wind so that the
possibility of losing any of the sample will be minimized.
8.6.3 Inspect the train prior to and during disassembly and note any
abnormal conditions such as particulate color, filter loading, impinger
liquid color, etc.
8.6.4 Container No. 1, Filter Assembly. Carefully remove the cooled
filter holder assembly from the Method 5 hot box and place it in the
transport case. Use a pair of clean gloves to handle the filter holder
assembly.
8.6.5 Container No. 2, Probe Nozzle and Probe Liner Rinse. Rinse the
probe and nozzle components with acetone. Be certain that the probe and
nozzle brushes have been thoroughly rinsed prior to use as they can be a
source of contamination.
8.6.6 All Other Train Components. (Impingers) Same as Method 5.
8.7 Sample Storage and Transport. Whenever possible, containers
should be shipped in such a way that they remain upright at all times.
All appropriate dangerous goods shipping requirements must be observed
since acetone is a flammable liquid.
9. Quality Control.
9.1 Miscellaneous Field Quality Control Measures.
9.1.1 A quality control (QC) check of the volume metering system at
the field site is suggested before collecting the sample using the
procedures in Method 5, section 4.4.1.
9.1.2 All other quality control checks outlined in Methods 1, 2, 4
and 5 also apply to Method 5I. This includes procedures such as leak-
checks, equipment calibration checks, and independent checks of field
data sheets for reasonableness and completeness.
9.2 Quality Control Samples.
9.2.1 Required QC Sample. A laboratory reagent blank must be
collected and analyzed for each lot of acetone used for a field program
to confirm that it is of suitable purity. The particulate samples cannot
be blank corrected.
9.2.2 Recommended QC Samples. These samples may be collected and
archived for future analyses.
9.2.2.1 A field reagent blank is a recommended QC sample collected
from a portion of the acetone used for cleanup of the probe and nozzle.
Take 100 ml of this acetone directly from the wash bottle being used and
place it in a glass sample container labeled ``field acetone reagent
blank.'' At least one field reagent blank is recommended for every five
runs completed. The field reagent blank samples demonstrate the purity
of the acetone was maintained throughout the program.
[[Page 241]]
9.2.2.2 A field bias blank train is a recommended QC sample. This
sample is collected by recovering a probe and filter assembly that has
been assembled, taken to the sample location, leak checked, heated,
allowed to sit at the sample location for a similar duration of time as
a regular sample run, leak-checked again, and then recovered in the same
manner as a regular sample. Field bias blanks are not a Method
requirement, however, they are recommended and are very useful for
identifying sources of contamination in emission testing samples. Field
bias blank train results greater than 5 times the method detection limit
may be considered problematic.
10. Calibration and Standardization Same as Method 5, section 5.
10.1 Field Balance Calibration Check. Check the calibration of the
balance used to weigh impingers with a weight that is at least 500g or
within 50g of a loaded impinger. The weight must be ASTM E617-13
``Standard Specification for Laboratory Weights and Precision Mass
Standards'' (incorporated by reference--see 40 CFR 60.17) Class 6 (or
better). Daily, before use, the field balance must measure the weight
within 0.5g of the certified mass. If the daily
balance calibration check fails, perform corrective measures and repeat
the check before using balance.
10.2 Analytical Balance Calibration. Perform a multipoint
calibration (at least five points spanning the operational range) of the
analytical balance before the first use, and semiannually thereafter.
The calibration of the analytical balance must be conducted using ASTM
E617-13 ``Standard Specification for Laboratory Weights and Precision
Mass Standards'' (incorporated by reference--see 40 CFR 60.17) Class 2
(or better) tolerance weights. Audit the balance each day it is used for
gravimetric measurements by weighing at least one ASTM E617-13 Class 2
tolerance (or better) calibration weight that corresponds to 50 to 150
percent of the weight of one filter or between 1g and 5g. If the scale
cannot reproduce the value of the calibration weight to within 0.5 mg of
the certified mass, perform corrective measures and conduct the
multipoint calibration before use.
11. Analytical Procedures.
11.1 Analysis. Same as Method 5, sections 11.1-11.2.4, with the
following exceptions:
11.1.1 Container No. 1. Same as Method 5, section 11.2.1, with the
following exception: Use disposable gloves to remove each of the filter
holder assemblies from the desiccator, transport container, or sample
oven (after appropriate cooling).
11.1.2 Container No. 2. Same as Method 5, section 11.2.2, with the
following exception: It is recommended that the contents of Container
No. 2 be transferred to a 250 ml beaker with a Teflon liner or similar
container that has a minimal tare weight before bringing to dryness.
12. Data Analysis and Calculations.
12.1 Particulate Emissions. The analytical results cannot be blank
corrected for residual acetone found in any of the blanks. All other
sample calculations are identical to Method 5.
12.2 Paired Trains Outliers. a. Outliers are identified through the
determination of precision and any systemic bias of the paired trains.
Data that do not meet this criteria should be flagged as a data quality
problem. The primary reason for performing dual train sampling is to
generate information to quantify the precision of the Reference Method
data. The relative standard deviation (RSD) of paired data is the
parameter used to quantify data precision. RSD for two simultaneously
gathered data points is determined according to:
[GRAPHIC] [TIFF OMITTED] TR30SE99.008
where, Ca and Cb are concentration values determined from trains A and B
respectively. For RSD calculation, the concentration units are
unimportant so long as they are consistent.
b. A minimum precision criteria for Reference Method PM data is that
RSD for any data pair must be less than 10% as long as the mean PM
concentration is greater than 10 mg/dscm. If the mean PM concentration
is less than 10 mg/dscm higher RSD values are acceptable. At mean PM
concentration of 1 mg/dscm acceptable RSD for paired trains is 25%.
Between 1 and 10 mg/dscm acceptable RSD criteria should be linearly
scaled from 25% to 10%. Pairs of manual method data exceeding these RSD
criteria should be eliminated from the data set used to develop a PM
CEMS correlation or to assess RCA. If the mean PM concentration is less
than 1 mg/dscm, RSD does not apply and the mean result is acceptable.
13. Method Performance [Reserved]
14. Pollution Prevention [Reserved]
15. Waste Management [Reserved]
16. Alternative Procedures. Same as Method 5.
17. Bibliography. Same as Method 5.
18. Tables, Diagrams, Flowcharts and Validation Data. Figure 5I-1 is
a schematic of the sample train.
[[Page 242]]
[GRAPHIC] [TIFF OMITTED] TR30SE99.009
[36 FR 24877, Dec. 23, 1971]
Editorial Note: For Federal Register citations affecting appendix A-
3 to part 60, see the List of CFR sections Affected, which appears in
the Finding Aids section of the printed volume and at www.govinfo.gov.
[[Page 243]]
Sec. Appendix A-4 to Part 60--Test Methods 6 through 10B
Method 6--Determination of sulfur dioxide emissions from stationary
sources
Method 6A--Determination of sulfur dioxide, moisture, and carbon dioxide
emissions from fossil fuel combustion sources
Method 6B--Determination of sulfur dioxide and carbon dioxide daily
average emissions from fossil fuel combustion sources
Method 6C--Determination of Sulfur Dioxide Emissions From Stationary
Sources (Instrumental Analyzer Procedure)
Method 7--Determination of nitrogen oxide emissions from stationary
sources
Method 7A--Determination of nitrogen oxide emissions from stationary
sources--Ion chromatographic method
Method 7B--Determination of nitrogen oxide emissions from stationary
sources (Ultraviolet spectrophotometry)
Method 7C--Determination of nitrogen oxide emissions from stationary
sources--Alkaline-permanganate/colorimetric method
Method 7D--Determination of nitrogen oxide emissions from stationary
sources--Alkaline-permanganate/ion chromatographic method
Method 7E--Determination of Nitrogen Oxides Emissions From Stationary
Sources (Instrumental Analyzer Procedure)
Method 8--Determination of sulfuric acid mist and sulfur dioxide
emissions from stationary sources
Method 9--Visual determination of the opacity of emissions from
stationary sources
Alternate method 1--Determination of the opacity of emissions from
stationary sources remotely by lidar
Method 10--Determination of carbon monoxide emissions from stationary
sources
Method 10A--Determination of carbon monoxide emissions in certifying
continuous emission monitoring systems at petroleum refineries
Method 10B--Determination of carbon monoxide emissions from stationary
sources
The test methods in this appendix are referred to in Sec. 60.8
(Performance Tests) and Sec. 60.11 (Compliance With Standards and
Maintenance Requirements) of 40 CFR part 60, subpart A (General
Provisions). Specific uses of these test methods are described in the
standards of performance contained in the subparts, beginning with
Subpart D.
Within each standard of performance, a section title ``Test Methods
and Procedures'' is provided to: (1) Identify the test methods to be
used as reference methods to the facility subject to the respective
standard and (2) identify any special instructions or conditions to be
followed when applying a method to the respective facility. Such
instructions (for example, establish sampling rates, volumes, or
temperatures) are to be used either in addition to, or as a substitute
for procedures in a test method. Similarly, for sources subject to
emission monitoring requirements, specific instructions pertaining to
any use of a test method as a reference method are provided in the
subpart or in Appendix B.
Inclusion of methods in this appendix is not intended as an
endorsement or denial of their applicability to sources that are not
subject to standards of performance. The methods are potentially
applicable to other sources; however, applicability should be confirmed
by careful and appropriate evaluation of the conditions prevalent at
such sources.
The approach followed in the formulation of the test methods
involves specifications for equipment, procedures, and performance. In
concept, a performance specification approach would be preferable in all
methods because this allows the greatest flexibility to the user. In
practice, however, this approach is impractical in most cases because
performance specifications cannot be established. Most of the methods
described herein, therefore, involve specific equipment specifications
and procedures, and only a few methods in this appendix rely on
performance criteria.
Minor changes in the test methods should not necessarily affect the
validity of the results and it is recognized that alternative and
equivalent methods exist. section 60.8 provides authority for the
Administrator to specify or approve (1) equivalent methods, (2)
alternative methods, and (3) minor changes in the methodology of the
test methods. It should be clearly understood that unless otherwise
identified all such methods and changes must have prior approval of the
Administrator. An owner employing such methods or deviations from the
test methods without obtaining prior approval does so at the risk of
subsequent disapproval and retesting with approved methods.
Within the test methods, certain specific equipment or procedures
are recognized as being acceptable or potentially acceptable and are
specifically identified in the methods. The items identified as
acceptable options may be used without approval but must be identified
in the test report. The potentially approvable options are cited as
``subject to the approval of the Administrator'' or as ``or
equivalent.'' Such potentially approvable techniques or alternatives may
be used at the discretion of the owner without prior approval. However,
detailed descriptions for applying these potentially approvable
techniques or alternatives are not provided in the test methods. Also,
the potentially approvable options are not necessarily acceptable in all
applications. Therefore, an owner electing to use such potentially
approvable techniques or alternatives is responsible for: (1) assuring
that
[[Page 244]]
the techniques or alternatives are in fact applicable and are properly
executed; (2) including a written description of the alternative method
in the test report (the written method must be clear and must be capable
of being performed without additional instruction, and the degree of
detail should be similar to the detail contained in the test methods);
and (3) providing any rationale or supporting data necessary to show the
validity of the alternative in the particular application. Failure to
meet these requirements can result in the Administrator's disapproval of
the alternative.
Method 6--Determination of Sulfur Dioxide Emissions From Stationary
Sources
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 2, Method 3,
Method 5, and Method 8.
1.0 Scope and Application
1.1 Analytes.
------------------------------------------------------------------------
Analyte CAS No. Sensitivity
------------------------------------------------------------------------
SO2............................... 7449-09-5 3.4 mg SO2/m\3\
(2.12 x 10)-7 lb/
ft\3\
------------------------------------------------------------------------
1.2 Applicability. This method applies to the measurement of sulfur
dioxide (SO2) emissions from stationary sources.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 A gas sample is extracted from the sampling point in the stack.
The SO2 and the sulfur trioxide, including those fractions in
any sulfur acid mist, are separated. The SO2 fraction is
measured by the barium-thorin titration method.
3.0 Definitions [Reserved]
4.0 Interferences
4.1 Free Ammonia. Free ammonia interferes with this method by
reacting with SO2 to form particulate sulfite and by reacting
with the indicator. If free ammonia is present (this can be determined
by knowledge of the process and/or noticing white particulate matter in
the probe and isopropanol bubbler), alternative methods, subject to the
approval of the Administrator are required. One approved alternative is
listed in Reference 13 of section 17.0.
4.2 Water-Soluble Cations and Fluorides. The cations and fluorides
are removed by a glass wool filter and an isopropanol bubbler;
therefore, they do not affect the SO2 analysis. When samples
are collected from a gas stream with high concentrations of metallic
fumes (i.e., very fine cation aerosols) a high-efficiency glass fiber
filter must be used in place of the glass wool plug (i.e., the one in
the probe) to remove the cation interferent.
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user to establish appropriate safety and health practices and determine
the applicability of regulatory limitations before performing this test
method.
5.2 Corrosive reagents. The following reagents are hazardous.
Personal protective equipment and safe procedures are useful in
preventing chemical splashes. If contact occurs, immediately flush with
copious amounts of water for at least 15 minutes. Remove clothing under
shower and decontaminate. Treat residual chemical burns as thermal
burns.
5.2.1 Hydrogen Peroxide (H2O2). Irritating to
eyes, skin, nose, and lungs. 30% H2O2 is a strong
oxidizing agent. Avoid contact with skin, eyes, and combustible
material. Wear gloves when handling.
5.2.2 Sodium Hydroxide (NaOH). Causes severe damage to eyes and
skin. Inhalation causes irritation to nose, throat, and lungs. Reacts
exothermically with limited amounts of water.
5.2.3 Sulfuric Acid (H2SO4). Rapidly
destructive to body tissue. Will cause third degree burns. Eye damage
may result in blindness. Inhalation may be fatal from spasm of the
larynx, usually within 30 minutes. May cause lung tissue damage with
edema. 1 mg/m\3\ for 8 hours will cause lung damage or, in higher
concentrations, death. Provide ventilation to limit inhalation. Reacts
violently with metals and organics.
6.0 Equipment and Supplies
6.1 Sample Collection. The following items are required for sample
collection:
6.1.1 Sampling Train. A schematic of the sampling train is shown in
Figure 6-1. The sampling equipment described in Method 8 may be
substituted in place of the midget impinger equipment of Method 6.
However, the Method 8 train must be modified to include a heated filter
between the probe and isopropanol impinger, and the operation of the
sampling train and sample analysis must be at the flow rates and
solution volumes defined in Method 8. Alternatively, SO2 may
be determined simultaneously with particulate
[[Page 245]]
matter and moisture determinations by either (1) replacing the water in
a Method 5 impinger system with a 3 percent H2O2
solution, or (2) replacing the Method 5 water impinger system with a
Method 8 isopropanol-filter-H2O2 system. The
analysis for SO2 must be consistent with the procedure of
Method 8. The Method 6 sampling train consists of the following
components:
6.1.1.1 Probe. Borosilicate glass or stainless steel (other
materials of construction may be used, subject to the approval of the
Administrator), approximately 6 mm (0.25 in.) inside diameter, with a
heating system to prevent water condensation and a filter (either in-
stack or heated out-of-stack) to remove particulate matter, including
sulfuric acid mist. A plug of glass wool is a satisfactory filter.
6.1.1.2 Bubbler and Impingers. One midget bubbler with medium-coarse
glass frit and borosilicate or quartz glass wool packed in top (see
Figure 6-1) to prevent sulfuric acid mist carryover, and three 30-ml
midget impingers. The midget bubbler and midget impingers must be
connected in series with leak-free glass connectors. Silicone grease may
be used, if necessary, to prevent leakage. A midget impinger may be used
in place of the midget bubbler.
Note: Other collection absorbers and flow rates may be used, subject
to the approval of the Administrator, but the collection efficiency must
be shown to be at least 99 percent for each test run and must be
documented in the report. If the efficiency is found to be acceptable
after a series of three tests, further documentation is not required. To
conduct the efficiency test, an extra absorber must be added and
analyzed separately. This extra absorber must not contain more than 1
percent of the total SO2.
6.1.1.3 Glass Wool. Borosilicate or quartz.
6.1.1.4 Stopcock Grease. Acetone-insoluble, heat-stable silicone
grease may be used, if necessary.
6.1.1.5 Temperature Sensor. Dial thermometer, or equivalent, to
measure temperature of gas leaving impinger train to within 1 [deg]C (2
[deg]F).
6.1.1.6 Drying Tube. Tube packed with 6- to 16- mesh indicating-type
silica gel, or equivalent, to dry the gas sample and to protect the
meter and pump. If silica gel is previously used, dry at 177 [deg]C (350
[deg]F) for 2 hours. New silica gel may be used as received.
Alternatively, other types of desiccants (equivalent or better) may be
used, subject to the approval of the Administrator.
6.1.1.7 Valve. Needle valve, to regulate sample gas flow rate.
6.1.1.8 Pump. Leak-free diaphragm pump, or equivalent, to pull gas
through the train. Install a small surge tank between the pump and rate
meter to negate the pulsation effect of the diaphragm pump on the rate
meter.
6.1.1.9 Rate Meter. Rotameter, or equivalent, capable of measuring
flow rate to within 2 percent of the selected flow rate of about 1
liter/min (0.035 cfm).
6.1.1.10 Volume Meter. Dry gas meter (DGM), sufficiently accurate to
measure the sample volume to within 2 percent, calibrated at the
selected flow rate and conditions actually encountered during sampling,
and equipped with a temperature sensor (dial thermometer, or equivalent)
capable of measuring temperature accurately to within 3 [deg]C (5.4
[deg]F). A critical orifice may be used in place of the DGM specified in
this section provided that it is selected, calibrated, and used as
specified in section 16.0.
6.1.2 Barometer. Mercury, aneroid, or other barometer capable of
measuring atmospheric pressure to within 2.5 mm Hg (0.1 in. Hg). See the
note in Method 5, section 6.1.2.
6.1.3 Vacuum Gauge and Rotameter. At least 760-mm Hg (30-in. Hg)
gauge and 0- to 40-ml/min rotameter, to be used for leak-check of the
sampling train.
6.2 Sample Recovery. The following items are needed for sample
recovery:
6.2.1 Wash Bottles. Two polyethylene or glass bottles, 500-ml.
6.2.2 Storage Bottles. Polyethylene bottles, 100-ml, to store
impinger samples (one per sample).
6.3 Sample Analysis. The following equipment is needed for sample
analysis:
6.3.1 Pipettes. Volumetric type, 5-ml, 20-ml (one needed per
sample), and 25-ml sizes.
6.3.2 Volumetric Flasks. 100-ml size (one per sample) and 1000-ml
size.
6.3.3 Burettes. 5- and 50-ml sizes.
6.3.4 Erlenmeyer Flasks. 250-ml size (one for each sample, blank,
and standard).
6.3.5 Dropping Bottle. 125-ml size, to add indicator.
6.3.6 Graduated Cylinder. 100-ml size.
6.3.7 Spectrophotometer. To measure absorbance at 352 nm.
7.0 Reagents and Standards
Note: Unless otherwise indicated, all reagents must conform to the
specifications established by the Committee on Analytical Reagents of
the American Chemical Society. Where such specifications are not
available, use the best available grade.
7.1 Sample Collection. The following reagents are required for
sample collection:
7.1.1 Water. Deionized distilled to conform to ASTM Specification D
1193-77 or 91 Type 3 (incorporated by reference--see Sec. 60.17). The
KMnO4 test for oxidizable organic matter may be omitted when
high concentrations of organic matter are not expected to be present.
7.1.2 Isopropanol, 80 Percent by Volume. Mix 80 ml of isopropanol
with 20 ml of water.
[[Page 246]]
7.1.2.1 Check each lot of isopropanol for peroxide impurities as
follows: Shake 10 ml of isopropanol with 10 ml of freshly prepared 10
percent potassium iodide solution. Prepare a blank by similarly treating
10 ml of water. After 1 minute, read the absorbance at 352 nm on a
spectrophotometer using a 1-cm path length. If absorbance exceeds 0.1,
reject alcohol for use.
7.1.2.2 Peroxides may be removed from isopropanol by redistilling or
by passage through a column of activated alumina; however, reagent grade
isopropanol with suitably low peroxide levels may be obtained from
commercial sources. Rejection of contaminated lots may, therefore, be a
more efficient procedure.
7.1.3 Hydrogen Peroxide (H2O2), 3 Percent by
Volume. Add 10 ml of 30 percent H2O2 to 90 ml of
water. Prepare fresh daily.
7.1.4 Potassium Iodide Solution, 10 Percent Weight by Volume (w/v).
Dissolve 10.0 g of KI in water, and dilute to 100 ml. Prepare when
needed.
7.2 Sample Recovery. The following reagents are required for sample
recovery:
7.2.1 Water. Same as in section 7.1.1.
7.2.2 Isopropanol, 80 Percent by Volume. Same as in section 7.1.2.
7.3 Sample Analysis. The following reagents and standards are
required for sample analysis:
7.3.1 Water. Same as in section 7.1.1.
7.3.2 Isopropanol, 100 Percent.
7.3.3 Thorin Indicator. 1-(o-arsonophenylazo)-2-naphthol-3,6-
disulfonic acid, disodium salt, or equivalent. Dissolve 0.20 g in 100 ml
of water.
7.3.4 Barium Standard Solution, 0.0100 N. Dissolve 1.95 g of barium
perchlorate trihydrate [Ba(ClO4)2 3H2O]
in 200 ml water, and dilute to 1 liter with isopropanol. Alternatively,
1.22 g of barium chloride dihydrate [BaCl2 2H2O]
may be used instead of the barium perchlorate trihydrate. Standardize as
in section 10.5.
7.3.5 Sulfuric Acid Standard, 0.0100 N. Purchase or standardize to
0.0002 N against 0.0100 N NaOH which has
previously been standardized against potassium acid phthalate (primary
standard grade).
8.0 Sample Collection, Preservation, Storage and Transport
8.1 Preparation of Sampling Train. Measure 15 ml of 80 percent
isopropanol into the midget bubbler and 15 ml of 3 percent
H2O2 into each of the first two midget impingers.
Leave the final midget impinger dry. Assemble the train as shown in
Figure 6-1. Adjust the probe heater to a temperature sufficient to
prevent water condensation. Place crushed ice and water around the
impingers.
8.2 Sampling Train Leak-Check Procedure. A leak-check prior to the
sampling run is recommended, but not required. A leak-check after the
sampling run is mandatory. The leak-check procedure is as follows:
8.2.1 Temporarily attach a suitable (e.g., 0- to 40- ml/min)
rotameter to the outlet of the DGM, and place a vacuum gauge at or near
the probe inlet. Plug the probe inlet, pull a vacuum of at least 250 mm
Hg (10 in. Hg), and note the flow rate as indicated by the rotameter. A
leakage rate in excess of 2 percent of the average sampling rate is not
acceptable.
Note: Carefully (i.e., slowly) release the probe inlet plug before
turning off the pump.
8.2.2 It is suggested (not mandatory) that the pump be leak-checked
separately, either prior to or after the sampling run. To leak-check the
pump, proceed as follows: Disconnect the drying tube from the probe-
impinger assembly. Place a vacuum gauge at the inlet to either the
drying tube or the pump, pull a vacuum of 250 mm Hg (10 in. Hg), plug or
pinch off the outlet of the flow meter, and then turn off the pump. The
vacuum should remain stable for at least 30 seconds.
If performed prior to the sampling run, the pump leak-check shall
precede the leak-check of the sampling train described immediately
above; if performed after the sampling run, the pump leak-check shall
follow the sampling train leak-check.
8.2.3 Other leak-check procedures may be used, subject to the
approval of the Administrator.
8.3 Sample Collection.
8.3.1 Record the initial DGM reading and barometric pressure. To
begin sampling, position the tip of the probe at the sampling point,
connect the probe to the bubbler, and start the pump. Adjust the sample
flow to a constant rate of approximately 1.0 liter/min as indicated by
the rate meter. Maintain this constant rate (10
percent) during the entire sampling run.
8.3.2 Take readings (DGM volume, temperatures at DGM and at impinger
outlet, and rate meter flow rate) at least every 5 minutes. Add more ice
during the run to keep the temperature of the gases leaving the last
impinger at 20 [deg]C (68 [deg]F) or less.
8.3.3 At the conclusion of each run, turn off the pump, remove the
probe from the stack, and record the final readings. Conduct a leak-
check as described in section 8.2. (This leak-check is mandatory.) If a
leak is detected, void the test run or use procedures acceptable to the
Administrator to adjust the sample volume for the leakage.
8.3.4 Drain the ice bath, and purge the remaining part of the train
by drawing clean ambient air through the system for 15 minutes at the
sampling rate. Clean ambient air can be provided by passing air through
a charcoal filter or through an extra midget impinger containing 15 ml
of 3 percent H2O2. Alternatively, ambient air
without purification may be used.
[[Page 247]]
8.4 Sample Recovery. Disconnect the impingers after purging. Discard
the contents of the midget bubbler. Pour the contents of the midget
impingers into a leak-free polyethylene bottle for shipment. Rinse the
three midget impingers and the connecting tubes with water, and add the
rinse to the same storage container. Mark the fluid level. Seal and
identify the sample container.
9.0 Quality Control
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
7.1.2.................... Isopropanol check.. Ensure acceptable level
of peroxide impurities
in isopropanol.
8.2, 10.1-10.4........... Sampling equipment Ensure accurate
leak-check and measurement of stack
calibration. gas flow rate, sample
volume.
10.5..................... Barium standard Ensure precision of
solution normality determination
standardization.
11.2.3................... Replicate Ensure precision of
titrations. titration
determinations.
------------------------------------------------------------------------
10.0 Calibration and Standardization
10.1 Volume Metering System.
10.1.1 Initial Calibration.
10.1.1.1 Before its initial use in the field, leak-check the
metering system (drying tube, needle valve, pump, rate meter, and DGM)
as follows: Place a vacuum gauge at the inlet to the drying tube and
pull a vacuum of 250 mm Hg (10 in. Hg). Plug or pinch off the outlet of
the flow meter, and then turn off the pump. The vacuum must remain
stable for at least 30 seconds. Carefully release the vacuum gauge
before releasing the flow meter end.
10.1.1.2 Remove the drying tube, and calibrate the metering system
(at the sampling flow rate specified by the method) as follows: Connect
an appropriately sized wet-test meter (e.g., 1 liter per revolution) to
the inlet of the needle valve. Make three independent calibration runs,
using at least five revolutions of the DGM per run. Calculate the
calibration factor Y (wet-test meter calibration volume divided by the
DGM volume, both volumes adjusted to the same reference temperature and
pressure) for each run, and average the results (Yi). If any
Y-value deviates by more than 2 percent from (Yi), the
metering system is unacceptable for use. If the metering system is
acceptable, use (Yi) as the calibration factor for subsequent
test runs.
10.1.2 Post-Test Calibration Check. After each field test series,
conduct a calibration check using the procedures outlined in section
10.1.1.2, except that three or more revolutions of the DGM may be used,
and only two independent runs need be made. If the average of the two
post-test calibration factors does not deviate by more than 5 percent
from Yi, then Yi is accepted as the DGM
calibration factor (Y), which is used in Equation 6-1 to calculate
collected sample volume (see section 12.2). If the deviation is more
than 5 percent, recalibrate the metering system as in section 10.1.1,
and determine a post-test calibration factor (Yf). Compare
Yi and Yf; the smaller of the two factors is
accepted as the DGM calibration factor. If recalibration indicates that
the metering system is unacceptable for use, either void the test run or
use methods, subject to the approval of the Administrator, to determine
an acceptable value for the collected sample volume.
10.1.3 DGM as a Calibration Standard. A DGM may be used as a
calibration standard for volume measurements in place of the wet-test
meter specified in section 10.1.1.2, provided that it is calibrated
initially and recalibrated periodically according to the same procedures
outlined in Method 5, section 10.3 with the following exceptions: (a)
the DGM is calibrated against a wet-test meter having a capacity of 1
liter/rev (0.035 ft\3\/rev) or 3 liters/rev (0.1 ft\3\/rev) and having
the capability of measuring volume to within 1 percent; (b) the DGM is
calibrated at 1 liter/min (0.035 cfm); and (c) the meter box of the
Method 6 sampling train is calibrated at the same flow rate.
10.2 Temperature Sensors. Calibrate against mercury-in-glass
thermometers. An alternative mercury-free thermometer may be used if the
thermometer is, at a minimum, equivalent in terms of performance or
suitably effective for the specific temperature measurement application.
10.3 Rate Meter. The rate meter need not be calibrated, but should
be cleaned and maintained according to the manufacturer's instructions.
10.4 Barometer. Calibrate against a mercury barometer or NIST-
traceable barometer prior to the field test.
10.5 Barium Standard Solution. Standardize the barium perchlorate or
chloride solution against 25 ml of standard sulfuric acid to which 100
ml of 100 percent isopropanol has been added. Run duplicate analyses.
Calculate the normality using the average of duplicate analyses where
the titrations agree within 1 percent or 0.2 ml, whichever is larger.
11.0 Analytical Procedure
11.1 Sample Loss Check. Note level of liquid in container and
confirm whether any sample was lost during shipment; note this
[[Page 248]]
finding on the analytical data sheet. If a noticeable amount of leakage
has occurred, either void the sample or use methods, subject to the
approval of the Administrator, to correct the final results.
11.2 Sample Analysis.
11.2.1 Transfer the contents of the storage container to a 100-ml
volumetric flask, dilute to exactly 100 ml with water, and mix the
diluted sample.
11.2.2 Pipette a 20-ml aliquot of the diluted sample into a 250-ml
Erlenmeyer flask and add 80 ml of 100 percent isopropanol plus two to
four drops of thorin indicator. While stirring the solution, titrate to
a pink endpoint using 0.0100 N barium standard solution.
11.2.3 Repeat the procedures in section 11.2.2, and average the
titration volumes. Run a blank with each series of samples. Replicate
titrations must agree within 1 percent or 0.2 ml, whichever is larger.
Note: Protect the 0.0100 N barium standard solution from evaporation
at all times.
12.0 Data Analysis and Calculations
Carry out calculations, retaining at least one extra significant
figure beyond that of the acquired data. Round off figures after final
calculation.
12.1 Nomenclature
CSO2 = Concentration of SO2, dry basis, corrected
to standard conditions, mg/dscm (lb/dscf).
N = Normality of barium standard titrant, meq/ml.
Pbar = Barometric pressure, mm Hg (in. Hg).
Pstd = Standard absolute pressure, 760 mm Hg (29.92 in. Hg).
Tm = Average DGM absolute temperature, [deg]K ([deg]R).
Tstd = Standard absolute temperature, 293 [deg]K (528
[deg]R).
Va = Volume of sample aliquot titrated, ml.
Vm = Dry gas volume as measured by the DGM, dcm (dcf).
Vm(std) = Dry gas volume measured by the DGM, corrected to
standard conditions, dscm (dscf).
Vsoln = Total volume of solution in which the SO2
sample is contained, 100 ml.
Vt = Volume of barium standard titrant used for the sample
(average of replicate titration), ml.
Vtb = Volume of barium standard titrant used for the blank,
ml.
Y = DGM calibration factor.
12.2 Dry Sample Gas Volume, Corrected to Standard Conditions.
[GRAPHIC] [TIFF OMITTED] TR17OC00.181
Where:
K1 = 0.3855 [deg]K/mm Hg for metric units,
K1 = 17.65 [deg]R/in. Hg for English units.
12.3 SO2 Concentration.
[GRAPHIC] [TIFF OMITTED] TR17OC00.182
Where:
K2 = 32.03 mg SO2/meq for metric units,
K2 = 7.061 x 10-5 lb SO2/meq for
English units.
13.0 Method Performance
13.1 Range. The minimum detectable limit of the method has been
determined to be 3.4 mg SO2/m\3\ (2.12 x 10-7 lb/
ft\3\). Although no upper limit has been established, tests have shown
that concentrations as high as 80,000 mg/m\3\ (0.005 lb/ft\3\) of
SO2 can be collected efficiently at a rate of 1.0 liter/min
(0.035 cfm) for 20 minutes in two midget impingers, each containing 15
ml of 3 percent H2O2. Based on theoretical
calculations, the upper concentration limit in a 20 liter (0.7 ft\3\)
sample is about 93,300 mg/m\3\ (0.00583 lb/ft\3\).
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Alternative Procedures
16.1 Nomenclature. Same as section 12.1, with the following
additions:
Bwa = Water vapor in ambient air, proportion by volume.
Ma = Molecular weight of the ambient air saturated at
impinger temperature, g/g-mole (lb/lb-mole).
Ms = Molecular weight of the sample gas saturated at impinger
temperature, g/g-mole (lb/lb-mole).
Pc = Inlet vacuum reading obtained during the calibration
run, mm Hg (in. Hg).
Psr = Inlet vacuum reading obtained during the sampling run,
mm Hg (in. Hg).
[[Page 249]]
Qstd = Volumetric flow rate through critical orifice, scm/min
(scf/min).
Qstd = Average flow rate of pre-test and post-test
calibration runs, scm/min (scf/min).
Tamb = Ambient absolute temperature of air, [deg]K ([deg]R).
Vsb = Volume of gas as measured by the soap bubble meter,
m\3\ (ft\3\).
Vsb(std) = Volume of gas as measured by the soap bubble
meter, corrected to standard conditions, scm (scf).
[thetas] = Soap bubble travel time, min.
[thetas]s = Time, min.
16.2 Critical Orifices for Volume and Rate Measurements. A critical
orifice may be used in place of the DGM specified in section 6.1.1.10,
provided that it is selected, calibrated, and used as follows:
16.2.1 Preparation of Sampling Train. Assemble the sampling train as
shown in Figure 6-2. The rate meter and surge tank are optional but are
recommended in order to detect changes in the flow rate.
Note: The critical orifices can be adapted to a Method 6 type
sampling train as follows: Insert sleeve type, serum bottle stoppers
into two reducing unions. Insert the needle into the stoppers as shown
in Figure 6-3.
16.2.2 Selection of Critical Orifices.
16.2.2.1 The procedure that follows describes the use of hypodermic
needles and stainless steel needle tubings, which have been found
suitable for use as critical orifices. Other materials and critical
orifice designs may be used provided the orifices act as true critical
orifices, (i.e., a critical vacuum can be obtained) as described in this
section. Select a critical orifice that is sized to operate at the
desired flow rate. The needle sizes and tubing lengths shown in Table 6-
1 give the following approximate flow rates.
16.2.2.2 Determine the suitability and the appropriate operating
vacuum of the critical orifice as follows: If applicable, temporarily
attach a rate meter and surge tank to the outlet of the sampling train,
if said equipment is not present (see section 16.2.1). Turn on the pump
and adjust the valve to give an outlet vacuum reading corresponding to
about half of the atmospheric pressure. Observe the rate meter reading.
Slowly increase the vacuum until a stable reading is obtained on the
rate meter. Record the critical vacuum, which is the outlet vacuum when
the rate meter first reaches a stable value. Orifices that do not reach
a critical value must not be used.
16.2.3 Field Procedures.
16.2.3.1 Leak-Check Procedure. A leak-check before the sampling run
is recommended, but not required. The leak-check procedure is as
follows: Temporarily attach a suitable (e.g., 0-40 ml/min) rotameter and
surge tank, or a soap bubble meter and surge tank to the outlet of the
pump. Plug the probe inlet, pull an outlet vacuum of at least 250 mm Hg
(10 in. Hg), and note the flow rate as indicated by the rotameter or
bubble meter. A leakage rate in excess of 2 percent of the average
sampling rate (Qstd) is not acceptable. Carefully release the
probe inlet plug before turning off the pump.
16.2.3.2 Moisture Determination. At the sampling location, prior to
testing, determine the percent moisture of the ambient air using the wet
and dry bulb temperatures or, if appropriate, a relative humidity meter.
16.2.3.3 Critical Orifice Calibration. At the sampling location,
prior to testing, calibrate the entire sampling train (i.e., determine
the flow rate of the sampling train when operated at critical
conditions). Attach a 500-ml soap bubble meter to the inlet of the
probe, and operate the sampling train at an outlet vacuum of 25 to 50 mm
Hg (1 to 2 in. Hg) above the critical vacuum. Record the information
listed in Figure 6-4. Calculate the standard volume of air measured by
the soap bubble meter and the volumetric flow rate using the equations
below:
[GRAPHIC] [TIFF OMITTED] TR17OC00.184
[GRAPHIC] [TIFF OMITTED] TR17OC00.185
16.2.3.4 Sampling.
16.2.3.4.1 Operate the sampling train for sample collection at the
same vacuum used during the calibration run. Start the watch and pump
simultaneously. Take readings (temperature, rate meter, inlet vacuum,
and outlet vacuum) at least every 5 minutes. At the end of the sampling
run, stop the watch and pump simultaneously.
16.2.3.4.2 Conduct a post-test calibration run using the calibration
procedure outlined in section 16.2.3.3. If the Qstd obtained
before and after the test differ by more than 5 percent, void the test
run; if not, calculate the volume of the gas measured with the critical
orifice using Equation 6-6 as follows:
[[Page 250]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.186
16.2.3.4.3 If the percent difference between the molecular weight of
the ambient air at saturated conditions and the sample gas is more that
3 percent, then the molecular weight of the gas
sample must be considered in the calculations using the following
equation:
[GRAPHIC] [TIFF OMITTED] TR17OC00.187
Note: A post-test leak-check is not necessary because the post-test
calibration run results will indicate whether there is any leakage.
16.2.3.4.4 Drain the ice bath, and purge the sampling train using
the procedure described in section 8.3.4.
16.3 Elimination of Ammonia Interference. The following alternative
procedures must be used in addition to those specified in the method
when sampling at sources having ammonia emissions.
16.3.1 Sampling. The probe shall be maintained at 275 [deg]C (527
[deg]F) and equipped with a high-efficiency in-stack filter (glass
fiber) to remove particulate matter. The filter material shall be
unreactive to SO2. Whatman 934AH (formerly Reeve Angel 934AH)
filters treated as described in Reference 10 in section 17.0 of Method 5
is an example of a filter that has been shown to work. Where alkaline
particulate matter and condensed moisture are present in the gas stream,
the filter shall be heated above the moisture dew point but below 225
[deg]C (437 [deg]F).
16.3.2 Sample Recovery. Recover the sample according to section 8.4
except for discarding the contents of the midget bubbler. Add the
bubbler contents, including the rinsings of the bubbler with water, to a
separate polyethylene bottle from the rest of the sample. Under normal
testing conditions where sulfur trioxide will not be present
significantly, the tester may opt to delete the midget bubbler from the
sampling train. If an approximation of the sulfur trioxide concentration
is desired, transfer the contents of the midget bubbler to a separate
polyethylene bottle.
16.3.3 Sample Analysis. Follow the procedures in sections 11.1 and
11.2, except add 0.5 ml of 0.1 N HCl to the Erlenmeyer flask and mix
before adding the indicator. The following analysis procedure may be
used for an approximation of the sulfur trioxide concentration. The
accuracy of the calculated concentration will depend upon the ammonia to
SO2 ratio and the level of oxygen present in the gas stream.
A fraction of the SO2 will be counted as sulfur trioxide as
the ammonia to SO2 ratio and the sample oxygen content
increases. Generally, when this ratio is 1 or less and the oxygen
content is in the range of 5 percent, less than 10 percent of the
SO2 will be counted as sulfur trioxide. Analyze the peroxide
and isopropanol sample portions separately. Analyze the peroxide portion
as described above. Sulfur trioxide is determined by difference using
sequential titration of the isopropanol portion of the sample. Transfer
the contents of the isopropanol storage container to a 100-ml volumetric
flask, and dilute to exactly 100 ml with water. Pipette a 20-ml aliquot
of this solution into a 250-ml Erlenmeyer flask, add 0.5 ml of 0.1 N
HCl, 80 ml of 100 percent isopropanol, and two to four drops of thorin
indicator. Titrate to a pink endpoint using 0.0100 N barium perchlorate.
Repeat and average the titration volumes that agree within 1 percent or
0.2 ml, whichever is larger. Use this volume in Equation 6-2 to
determine the sulfur trioxide concentration. From the flask containing
the remainder of the isopropanol sample, determine the fraction of
SO2 collected in the bubbler by pipetting 20-ml aliquots into
250-ml Erlenmeyer flasks. Add 5 ml of 3 percent
H2O2, 100 ml of 100 percent isopropanol, and two
to four drips of thorin indicator, and titrate as before. From this
titration volume, subtract the titrant volume determined for sulfur
trioxide, and add the titrant volume determined for the peroxide
portion. This final volume constitutes Vt, the volume of
barium perchlorate used for the SO2 sample.
17.0 References
1. Atmospheric Emissions from Sulfuric Acid Manufacturing Processes.
U.S. DHEW, PHS, Division of Air Pollution. Public
[[Page 251]]
Health Service Publication No. 999-AP-13. Cincinnati, OH. 1965.
2. Corbett, P.F. The Determination of SO2 and
SO3 in Flue Gases. Journal of the Institute of Fuel. 24:237-
243. 1961.
3. Matty, R.E., and E.K. Diehl. Measuring Flue-Gas SO2
and SO3. Power. 101:94-97. November 1957.
4. Patton, W.F., and J.A. Brink, Jr. New Equipment and Techniques
for Sampling Chemical Process Gases. J. Air Pollution Control
Association. 13:162. 1963.
5. Rom, J.J. Maintenance, Calibration, and Operation of Isokinetic
Source Sampling Equipment. Office of Air Programs, U.S. Environmental
Protection Agency. Research Triangle Park, NC. APTD-0576. March 1972.
6. Hamil, H.F., and D.E. Camann. Collaborative Study of Method for
the Determination of Sulfur Dioxide Emissions from Stationary Sources
(Fossil-Fuel Fired Steam Generators). U.S. Environmental Protection
Agency, Research Triangle Park, NC. EPA-650/4-74-024. December 1973.
7. Annual Book of ASTM Standards. Part 31; Water, Atmospheric
Analysis. American Society for Testing and Materials. Philadelphia, PA.
1974. pp. 40-42.
8. Knoll, J.E., and M.R. Midgett. The Application of EPA Method 6 to
High Sulfur Dioxide Concentrations. U.S. Environmental Protection
Agency. Research Triangle Park, NC. EPA-600/4-76-038. July 1976.
9. Westlin, P.R., and R.T. Shigehara. Procedure for Calibrating and
Using Dry Gas Volume Meters as Calibration Standards. Source Evaluation
Society Newsletter. 3(1):17-30. February 1978.
10. Yu, K.K. Evaluation of Moisture Effect on Dry Gas Meter
Calibration. Source Evaluation Society Newsletter. 5(1):24-28. February
1980.
11. Lodge, J.P., Jr., et al. The Use of Hypodermic Needles as
Critical Orifices in Air Sampling. J. Air Pollution Control Association.
16:197-200. 1966.
12. Shigehara, R.T., and C.B. Sorrell. Using Critical Orifices as
Method 5 CalibrationStandards. Source Evaluation Society Newsletter.
10:4-15. August 1985.
13. Curtis, F., Analysis of Method 6 Samples in the Presence of
Ammonia. Source Evaluation Society Newsletter. 13(1):9-15 February 1988.
18.0 Tables, Diagrams, Flowcharts and Validation Data
Table 6-1--Approximate Flow Rates for Various Needle Sizes
------------------------------------------------------------------------
Needle Flow rate
Needle size (gauge) length (cm) (ml/min)
------------------------------------------------------------------------
21............................................ 7.6 1,100
22............................................ 2.9 1,000
22............................................ 3.8 900
23............................................ 3.8 500
23............................................ 5.1 450
24............................................ 3.2 400
------------------------------------------------------------------------
[[Page 252]]
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[[Page 255]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.191
Method 6A--Determination of Sulfur Dioxide, Moisture, and Carbon Dioxide
From Fossil Fuel Combustion Sources
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 2, Method 3,
Method 5, Method 6, and Method 19.
1.0 Scope and Application
1.1 Analytes.
[[Page 256]]
------------------------------------------------------------------------
Analyte CAS No. Sensitivity
------------------------------------------------------------------------
SO2............................... 7449-09-05 3.4 mg SO2/m\3\
(2.12 x 10-7 lb/
ft\3\)
CO2............................... 124-38-9 N/A
H2O............................... 7732-18-5 N/A
------------------------------------------------------------------------
1.2 Applicability. This method is applicable for the determination
of sulfur dioxide (SO2) emissions from fossil fuel combustion
sources in terms of concentration (mg/dscm or lb/dscf) and in terms of
emission rate (ng/J or lb/10\6\ Btu) and for the determination of carbon
dioxide (CO2) concentration (percent). Moisture content
(percent), if desired, may also be determined by this method.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 A gas sample is extracted from a sampling point in the stack.
The SO2 and the sulfur trioxide, including those fractions in
any sulfur acid mist, are separated. The SO2 fraction is
measured by the barium-thorin titration method. Moisture and
CO2 fractions are collected in the same sampling train, and
are determined gravimetrically.
3.0 Definitions [Reserved]
4.0 Interferences
Same as Method 6, section 4.0.
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user to establish appropriate safety and health practices and determine
the applicability of regulatory limitations prior to performing this
test method.
5.2 Corrosive reagents. Same as Method 6, section 5.2.
6.0 Equipment and Supplies
6.1 Sample Collection. Same as Method 6, section 6.1, with the
exception of the following:
6.1.1 Sampling Train. A schematic of the sampling train used in this
method is shown in Figure 6A-1.
6.1.1.1 Impingers and Bubblers. Two 30 = ml midget impingers with a
1 = mm restricted tip and two 30 = ml midget bubblers with unrestricted
tips. Other types of impingers and bubblers (e.g., Mae West for
SO2 collection and rigid cylinders containing Drierite for
moisture absorbers), may be used with proper attention to reagent
volumes and levels, subject to the approval of the Administrator.
6.1.1.2 CO2 Absorber. A sealable rigid cylinder or bottle
with an inside diameter between 30 and 90 mm , a length between 125 and
250 mm, and appropriate connections at both ends. The filter may be a
separate heated unit or may be within the heated portion of the probe.
If the filter is within the sampling probe, the filter should not be
within 15 cm of the probe inlet or any unheated section of the probe,
such as the connection to the first bubbler. The probe and filter should
be heated to at least 20 [deg]C (68 [deg]F) above the source
temperature, but not greater than 120 [deg]C (248 [deg]F). The filter
temperature (i.e., the sample gas temperature) should be monitored to
assure the desired temperature is maintained. A heated Teflon connector
may be used to connect the filter holder or probe to the first impinger.
Note: For applications downstream of wet scrubbers, a heated out-of-
stack filter (either borosilicate glass wool or glass fiber mat) is
necessary.
6.2 Sample Recovery. Same as Method 6, section 6.2.
6.3 Sample Analysis. Same as Method 6, section 6.3, with the
addition of a balance to measure within 0.05 g.
7.0 Reagents and Standards
Note: Unless otherwise indicated, all reagents must conform to the
specifications established by the Committee on Analytical Reagents of
the American Chemical Society. Where such specifications are not
available, use the best available grade.
7.1 Sample Collection. Same as Method 6, section 7.1, with the
addition of the following:
7.1.1 Drierite. Anhydrous calcium sulfate (CaSO4)
desiccant, 8 mesh, indicating type is recommended.
Note: Do not use silica gel or similar desiccant in this
application.
7.1.2 CO2 Absorbing Material. Ascarite II. Sodium
hydroxide-coated silica, 8- to 20-mesh.
7.2 Sample Recovery and Analysis. Same as Method 6, sections 7.2 and
7.3, respectively.
8.0 Sample Collection, Preservation, Transport, and Storage
8.1 Preparation of Sampling Train.
8.1.1 Measure 15 ml of 80 percent isopropanol into the first midget
bubbler and 15 ml of 3 percent hydrogen peroxide into each of the two
midget impingers (the second
[[Page 257]]
and third vessels in the train) as described in Method 6, section 8.1.
Insert the glass wool into the top of the isopropanol bubbler as shown
in Figure 6A-1. Place about 25 g of Drierite into the second midget
bubbler (the fourth vessel in the train). Clean the outside of the
bubblers and impingers and allow the vessels to reach room temperature.
Weigh the four vessels simultaneously to the nearest 0.1 g, and record
this initial weight (mwi).
8.1.2 With one end of the CO2 absorber sealed, place
glass wool into the cylinder to a depth of about 1 cm (0.5 in.). Place
about 150 g of CO2 absorbing material in the cylinder on top
of the glass wool, and fill the remaining space in the cylinder with
glass wool. Assemble the cylinder as shown in figure 6A-2. With the
cylinder in a horizontal position, rotate it around the horizontal axis.
The CO2 absorbing material should remain in position during
the rotation, and no open spaces or channels should be formed. If
necessary, pack more glass wool into the cylinder to make the
CO2 absorbing material stable. Clean the outside of the
cylinder of loose dirt and moisture and allow the cylinder to reach room
temperature. Weigh the cylinder to the nearest 0.1 g, and record this
initial weight (mai).
8.1.3 Assemble the train as shown in figure 6A-1. Adjust the probe
heater to a temperature sufficient to prevent condensation (see note in
section 6.1). Place crushed ice and water around the impingers and
bubblers. Mount the CO2 absorber outside the water bath in a
vertical flow position with the sample gas inlet at the bottom. Flexible
tubing (e.g., Tygon) may be used to connect the last SO2
absorbing impinger to the moisture absorber and to connect the moisture
absorber to the CO2 absorber. A second, smaller
CO2 absorber containing Ascarite II may be added in-line
downstream of the primary CO2 absorber as a breakthrough
indicator. Ascarite II turns white when CO2 is absorbed.
8.2 Sampling Train Leak-Check Procedure and Sample Collection. Same
as Method 6, sections 8.2 and 8.3, respectively.
8.3 Sample Recovery.
8.3.1 Moisture Measurement. Disconnect the isopropanol bubbler, the
SO2 impingers, and the moisture absorber from the sample
train. Allow about 10 minutes for them to reach room temperature, clean
the outside of loose dirt and moisture, and weigh them simultaneously in
the same manner as in section 8.1. Record this final weight
(mwf).
8.3.2 Peroxide Solution. Discard the contents of the isopropanol
bubbler and pour the contents of the midget impingers into a leak-free
polyethylene bottle for shipping. Rinse the two midget impingers and
connecting tubes with water, and add the washing to the same storage
container.
8.3.3 CO2 Absorber. Allow the CO2 absorber to
warm to room temperature (about 10 minutes), clean the outside of loose
dirt and moisture, and weigh to the nearest 0.1 g in the same manner as
in section 8.1. Record this final weight (maf). Discard used
Ascarite II material.
9.0 Quality Control
Same as Method 6, section 9.0.
10.0 Calibration and Standardization
Same as Method 6, section 10.0.
11.0 Analytical Procedure
11.1 Sample Analysis. The sample analysis procedure for
SO2 is the same as that specified in Method 6, section 11.0.
12.0 Data Analysis and Calculations
Same as Method 6, section 12.0, with the addition of the following:
12.1 Nomenclature.
Cw = Concentration of moisture, percent.
CCO2 = Concentration of CO2, dry basis, percent.
ESO2 = Emission rate of SO2, ng/J (lb/10\6\ Btu).
FC = Carbon F-factor from Method 19 for the fuel burned,
dscm/J (dscf/10\6\ Btu).
mwi = Initial weight of impingers, bubblers, and moisture
absorber, g.
mwf = Final weight of impingers, bubblers, and moisture
absorber, g.
mai = Initial weight of CO2 absorber, g.
maf = Final weight of CO2 absorber, g.
mSO2 = Mass of SO2 collected, mg.
VCO2(std) = Equivalent volume of CO2 collected at
standard conditions, dscm (dscf).
Vw(std) = Equivalent volume of moisture collected at standard
conditions, scm (scf).
12.2 CO2 Volume Collected, Corrected to Standard
Conditions.
[GRAPHIC] [TIFF OMITTED] TR17OC00.192
Where:
K3 = Equivalent volume of gaseous CO2 at standard
conditions, 5.467 x 10-4 dscm/g (1.930 x
10-2 dscf/g).
12.3 Moisture Volume Collected, Corrected to Standard Conditions.
[GRAPHIC] [TIFF OMITTED] TR17OC00.193
Where:
K4 = Equivalent volume of water vapor at standard conditions,
1.336 x 10-3 scm/g (4.717 x 10-2 scf/g).
12.4 SO2 Concentration.
[[Page 258]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.194
Where:
K2 = 32.03 mg SO2/meq. SO2 (7.061 x
10-5 lb SO2/meq. SO2)
12.5 CO2 Concentration.
[GRAPHIC] [TIFF OMITTED] TR17OC00.195
12.6 Moisture Concentration.
[GRAPHIC] [TIFF OMITTED] TR17OC00.196
13.0 Method Performance
13.1 Range and Precision. The minimum detectable limit and the upper
limit for the measurement of SO2 are the same as for Method
6. For a 20-liter sample, this method has a precision of 0.5 percent CO2 for concentrations between
2.5 and 25 percent CO2 and 1.0 percent
moisture for moisture concentrations greater than 5 percent.
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Alternative Methods
If the only emission measurement desired is in terms of emission
rate of SO2 (ng/J or lb/10\6\ Btu), an abbreviated procedure
may be used. The differences between the above procedure and the
abbreviated procedure are described below.
16.1 Sampling Train. The sampling train is the same as that shown in
Figure 6A-1 and as described in section 6.1, except that the dry gas
meter is not needed.
16.2 Preparation of the Sampling Train. Follow the same procedure as
in section 8.1, except do not weigh the isopropanol bubbler, the
SO2 absorbing impingers, or the moisture absorber.
16.3 Sampling Train Leak-Check Procedure and Sample Collection.
Leak-check and operate the sampling train as described in section 8.2,
except that dry gas meter readings, barometric pressure, and dry gas
meter temperatures need not be recorded during sampling.
16.4 Sample Recovery. Follow the procedure in section 8.3, except do
not weigh the isopropanol bubbler, the SO2 absorbing
impingers, or the moisture absorber.
16.5 Sample Analysis. Analysis of the peroxide solution is the same
as that described in section 11.1.
16.6 Calculations.
16.6.1 SO2 Collected.
[GRAPHIC] [TIFF OMITTED] TR17OC00.197
Where:
K2 = 32.03 mg SO2/meq. SO2
K2 = 7.061 x 10-5 lb SO2/meq.
SO2
16.6.2 Sulfur Dioxide Emission Rate.
[[Page 259]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.198
Where:
K5 = 1.829 x 10\9\ mg/dscm
K2 = 0.1142 lb/dscf
17.0 References
Same as Method 6, section 17.0, References 1 through 8, with the
addition of the following:
1. Stanley, Jon and P.R. Westlin. An Alternate Method for Stack Gas
Moisture Determination. Source Evaluation Society Newsletter. 3(4).
November 1978.
2. Whittle, Richard N. and P.R. Westlin. Air Pollution Test Report:
Development and Evaluation of an Intermittent Integrated SO2/
CO2 Emission Sampling Procedure. Environmental Protection
Agency, Emission Standard and Engineering Division, Emission Measurement
Branch. Research Triangle Park, NC. December 1979. 14 pp.
18.0 Tables, Diagrams, Flowcharts, and Validation Data
[[Page 260]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.199
[[Page 261]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.410
Method 6B--Determination of Sulfur Dioxide and Carbon Dioxide Daily
Average Emissions From Fossil Fuel Combustion Sources
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 2, Method 3,
Method 5, Method 6, and Method 6A.
1.0 Scope and Application
1.1 Analytes.
[[Page 262]]
------------------------------------------------------------------------
Analyte CAS No. Sensitivity
------------------------------------------------------------------------
Sulfur dioxide (SO2).............. 7449-09-05 3.4 mg SO2/m\3\
(2.12 x 10-7 lb/
ft\3\)
Carbon dioxide (CO2).............. 124-38-9 N/A
------------------------------------------------------------------------
1.2 Applicability. This method is applicable for the determination
of SO2 emissions from combustion sources in terms of
concentration (ng/dscm or lb/dscf) and emission rate (ng/J or lb/10\6\
Btu), and for the determination of CO2 concentration
(percent) on a daily (24 hours) basis.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 A gas sample is extracted from the sampling point in the stack
intermittently over a 24-hour or other specified time period. The
SO2 fraction is measured by the barium-thorin titration
method. Moisture and CO2 fractions are collected in the same
sampling train, and are determined gravimetrically.
3.0 Definitions [Reserved]
4.0 Interferences
Same as Method 6, section 4.0.
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user to establish appropriate safety and health practices and determine
the applicability of regulatory limitations prior to performing this
test method.
5.2 Corrosive Reagents. Same as Method 6, section 5.2.
6.0 Equipment and Supplies
Same as Method 6A, section 6.0, with the following exceptions and
additions:
6.1 The isopropanol bubbler is not used. An empty bubbler for the
collection of liquid droplets, that does not allow direct contact
between the collected liquid and the gas sample, may be included in the
sampling train.
6.2 For intermittent operation, include an industrial timer-switch
designed to operate in the ``on'' position at least 2 minutes
continuously and ``off'' the remaining period over a repeating cycle.
The cycle of operation is designated in the applicable regulation. At a
minimum, the sampling operation should include at least 12, equal,
evenly-spaced periods per 24 hours.
6.3 Stainless steel sampling probes, type 316, are not recommended
for use with Method 6B because of potential sample contamination due to
corrosion. Glass probes or other types of stainless steel, e.g.,
Hasteloy or Carpenter 20, are recommended for long-term use.
Note: For applications downstream of wet scrubbers, a heated out-of-
stack filter (either borosilicate glass wool or glass fiber mat) is
necessary. Probe and filter heating systems capable of maintaining a
sample gas temperature of between 20 and 120 [deg]C (68 and 248 [deg]F)
at the filter are also required in these cases. The electric supply for
these heating systems should be continuous and separate from the timed
operation of the sample pump.
7.0 Reagents and Standards
Same as Method 6A, section 7.0, with the following exceptions:
7.1 Isopropanol is not used for sampling.
7.2 The hydrogen peroxide absorbing solution shall be diluted to no
less than 6 percent by volume, instead of 3 percent as specified in
Methods 6 and 6A.
7.3 If the Method 6B sampling train is to be operated in a low
sample flow condition (less than 100 ml/min or 0.21 ft\3\/hr), molecular
sieve material may be substituted for Ascarite II as the CO2
absorbing material. The recommended molecular sieve material is Union
Carbide \1/16\ inch pellets, 5 A[deg], or equivalent. Molecular sieve
material need not be discarded following the sampling run, provided that
it is regenerated as per the manufacturer's instruction. Use of
molecular sieve material at flow rates higher than 100 ml/min (0.21
ft\3\/hr) may cause erroneous CO2 results.
8.0 Sample Collection, Preservation, Transport, and Storage
8.1 Preparation of Sampling Train. Same as Method 6A, section 8.1,
with the addition of the following:
8.1.1 The sampling train is assembled as shown in Figure 6A-1 of
Method 6A, except that the isopropanol bubbler is not included.
8.1.2 Adjust the timer-switch to operate in the ``on'' position from
2 to 4 minutes on a 2-hour repeating cycle or other cycle specified in
the applicable regulation. Other timer sequences may be used with the
restriction that the total sample volume collected is between 25 and 60
liters (0.9 and 2.1 ft\3\) for the amounts of sampling reagents
prescribed in this method.
8.1.3 Add cold water to the tank until the impingers and bubblers
are covered at least two-thirds of their length. The impingers and
bubbler tank must be covered and protected from intense heat and direct
sunlight. If freezing conditions exist, the impinger solution and the
water bath must be protected.
Note: Sampling may be conducted continuously if a low flow-rate
sample pump [20
[[Page 263]]
to 40 ml/min (0.04 to 0.08 ft\3\/hr) for the reagent volumes described
in this method] is used. If sampling is continuous, the timer-switch is
not necessary. In addition, if the sample pump is designed for constant
rate sampling, the rate meter may be deleted. The total gas volume
collected should be between 25 and 60 liters (0.9 and 2.1 ft\3\) for the
amounts of sampling reagents prescribed in this method.
8.2 Sampling Train Leak-Check Procedure. Same as Method 6, section
8.2.
8.3 Sample Collection.
8.3.1 The probe and filter (either in-stack, out-of-stack, or both)
must be heated to a temperature sufficient to prevent water
condensation.
8.3.2 Record the initial dry gas meter reading. To begin sampling,
position the tip of the probe at the sampling point, connect the probe
to the first impinger (or filter), and start the timer and the sample
pump. Adjust the sample flow to a constant rate of approximately 1.0
liter/min (0.035 cfm) as indicated by the rotameter. Observe the
operation of the timer, and determine that it is operating as intended
(i.e., the timer is in the ``on'' position for the desired period, and
the cycle repeats as required).
8.3.3 One time between 9 a.m. and 11 a.m. during the 24-hour
sampling period, record the dry gas meter temperature (Tm)
and the barometric pressure (P(bar)).
8.3.4 At the conclusion of the run, turn off the timer and the
sample pump, remove the probe from the stack, and record the final gas
meter volume reading. Conduct a leak-check as described in section 8.2.
If a leak is found, void the test run or use procedures acceptable to
the Administrator to adjust the sample volume for leakage. Repeat the
steps in sections 8.3.1 to 8.3.4 for successive runs.
8.4 Sample Recovery. The procedures for sample recovery (moisture
measurement, peroxide solution, and CO2 absorber) are the
same as those in Method 6A, section 8.3.
9.0 Quality Control
Same as Method 6, section 9.0., with the exception of the
isopropanol-check.
10.0 Calibration and Standardization
Same as Method 6, section 10.0, with the addition of the following:
10.1 Periodic Calibration Check. After 30 days of operation of the
test train, conduct a calibration check according to the same procedures
as the post-test calibration check (Method 6, section 10.1.2). If the
deviation between initial and periodic calibration factors exceeds 5
percent, use the smaller of the two factors in calculations for the
preceding 30 days of data, but use the most recent calibration factor
for succeeding test runs.
11.0 Analytical Procedures
11.1 Sample Loss Check and Analysis. Same as Method 6, sections 11.1
and 11.2, respectively.
12.0 Data Analysis and Calculations
Same as Method 6A, section 12.0, except that Pbar and
Tm correspond to the values recorded in section 8.3.3 of this
method. The values are as follows:
Pbar = Initial barometric pressure for the test period, mm
Hg.
Tm = Absolute meter temperature for the test period, [deg]K.
13.0 Method Performance
13.1 Range.
13.1.1 Sulfur Dioxide. Same as Method 6.
13.1.2 Carbon Dioxide. Not determined.
13.2 Repeatability and Reproducibility. EPA-sponsored collaborative
studies were undertaken to determine the magnitude of repeatability and
reproducibility achievable by qualified testers following the procedures
in this method. The results of the studies evolve from 145 field tests
including comparisons with Methods 3 and 6. For measurements of emission
rates from wet, flue gas desulfurization units in (ng/J), the
repeatability (intra-laboratory precision) is 8.0 percent and the
reproducibility (inter-laboratory precision) is 11.1 percent.
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Alternative Methods
Same as Method 6A, section 16.0, except that the timer is needed and
is operated as outlined in this method.
17.0 References
Same as Method 6A, section 17.0, with the addition of the following:
1. Butler, Frank E., et. al. The Collaborative Test of Method 6B:
Twenty-Four-Hour Analysis of SO2 and CO2. JAPCA.
Vol. 33, No. 10. October 1983.
18.0 Tables, Diagrams, Flowcharts, and Validation Data [Reserved]
Method 6C--Determination of Sulfur Dioxide Emissions From Stationary
Sources (Instrumental Analyzer Procedure)
1.0 Scope and Application
What is Method 6C?
Method 6C is a procedure for measuring sulfur dioxide
(SO2) in stationary source emissions using a continuous
instrumental analyzer. Quality assurance and quality control
requirements are included to assure that
[[Page 264]]
you, the tester, collect data of known quality. You must document your
adherence to these specific requirements for equipment, supplies, sample
collection and analysis, calculations, and data analysis.
This method does not completely describe all equipment, supplies,
and sampling and analytical procedures you will need but refers to other
methods for some of the details. Therefore, to obtain reliable results,
you should also have a thorough knowledge of these additional test
methods which are found in appendix A to this part:
(a) Method 1--Sample and Velocity Traverses for Stationary Sources.
(b) Method 4--Determination of Moisture Content in Stack Gases.
(c) Method 6--Determination of Sulfur Dioxide Emissions from
Stationary Sources.
(d) Method 7E--Determination of Nitrogen Oxides Emissions from
Stationary Sources (Instrumental Analyzer Procedure).
1.1 Analytes. What does this method determine? This method measures
the concentration of sulfur dioxide.
------------------------------------------------------------------------
Analyte CAS No. Sensitivity
------------------------------------------------------------------------
SO2............................ 7446-09-5 Typically <2% of
Calibration Span.
------------------------------------------------------------------------
1.2 Applicability. When is this method required? The use of Method
6C may be required by specific New Source Performance Standards, Clean
Air Marketing rules, State Implementation Plans, and permits where
SO2 concentrations in stationary source emissions must be
measured, either to determine compliance with an applicable emission
standard or to conduct performance testing of a continuous emission
monitoring system (CEMS). Other regulations may also require the use of
Method 6C.
1.3 Data Quality Objectives. How good must my collected data be?
Refer to section 1.3 of Method 7E.
2.0 Summary of Method
In this method, you continuously sample the effluent gas and convey
the sample to an analyzer that measures the concentration of
SO2. You must meet the performance requirements of this
method to validate your data.
3.0 Definitions
Refer to section 3.0 of Method 7E for the applicable definitions.
4.0 Interferences
Refer to Section 4.0 of Method 7E.
5.0 Safety
Refer to section 5.0 of Method 7E.
6.0 Equipment and Supplies
Figure 7E-1 of Method 7E is a schematic diagram of an acceptable
measurement system.
6.1 What do I need for the measurement system? The essential
components of the measurement system are the same as those in sections
6.1 and 6.2 of Method 7E, except that the SO2 analyzer
described in section 6.2 of this method must be used instead of the
analyzer described in section 6.2 of Method 7E. You must follow the
noted specifications in section 6.1 of Method 7E.
6.2 What analyzer must I use? You may use an instrument that uses an
ultraviolet, non-dispersive infrared, fluorescence, or other detection
principle to continuously measure SO2 in the gas stream and
meets the performance specifications in section 13.0. The low-range and
dual-range analyzer provisions in sections 6.2.8.1 and 6.2.8.2 of Method
7E apply.
7.0 Reagents and Standards
7.1 Calibration Gas. What calibration gases do I need? Refer to
section 7.1 of Method 7E for the calibration gas requirements. Example
calibration gas mixtures are listed below.
(a) SO2 in nitrogen (N2).
(b) SO2 in air.
(c) SO2 and CO2 in N2.
(d) SO2 andO2 in N2.
(e) SO2/CO2/O2 gas mixture in
N2.
(f) CO2/NOX gas mixture in N2.
(g) CO2/SO2/NOX gas mixture in
N2.
7.2 Interference Check. What additional reagents do I need for the
interference check? The test gases for the interference check are listed
in Table 7E-3 of Method 7E. For the alternative interference check, you
must use the reagents described in section 7.0 of Method 6.
8.0 Sample Collection, Preservation, Storage, and Transport
8.1 Sampling Site and Sampling Points. You must follow the
procedures of section 8.1 of Method 7E.
8.2 Initial Measurement System Performance Tests. You must follow
the procedures in section 8.2 of Method 7E. If a dilution-type
measurement system is used, the special considerations in section 8.3 of
Method 7E also apply.
8.3 Interference Check. You must follow the procedures of section
8.2.7 of Method 7E
[[Page 265]]
to conduct an interference check, substituting SO2 for
NOX as the method pollutant. For dilution-type measurement
systems, you must use the alternative interference check procedure in
section 16 and a co-located, unmodified Method 6 sampling train.
8.4 Sample Collection. You must follow the procedures of section 8.4
of Method 7E.
8.5 Post-Run System Bias Check and Drift Assessment. You must follow
the procedures of section 8.5 of Method 7E.
9.0 Quality Control
Follow quality control procedures in section 9.0 of Method 7E.
10.0 Calibration and Standardization
Follow the procedures for calibration and standardization in section
10.0 of Method 7E.
11.0 Analytical Procedures
Because sample collection and analysis are performed together (see
section 8), additional discussion of the analytical procedure is not
necessary.
12.0 Calculations and Data Analysis
You must follow the applicable procedures for calculations and data
analysis in section 12.0 of Method 7E as applicable, substituting
SO2 for NOX as appropriate.
13.0 Method Performance
13.1 The specifications for the applicable performance checks are
the same as in section 13.0 of Method 7E.
13.2 Alternative Interference Check. The results are acceptable if
the difference between the Method 6C result and the modified Method 6
result is less than 7.0 percent of the Method 6 result for each of the
three test runs. For the purposes of comparison, the Method 6 and 6C
results must be expressed in the same units of measure.
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 Alternative Procedures
16.1 Alternative Interference Check. You may perform an alternative
interference check consisting of at least three comparison runs between
Method 6C and Method 6. This check validates the Method 6C results at
each particular source category (type of facility) where the check is
performed. When testing under conditions of low concentrations (<15
ppm), this alternative interference check is not allowed.
Note: The procedure described below applies to non-dilution sampling
systems only. If this alternative interference check is used for a
dilution sampling system, use a standard Method 6 sampling train and
extract the sample directly from the exhaust stream at points collocated
with the Method 6C sample probe.
a. Build the modified Method 6 sampling train (flow control valve,
two midget impingers containing 3 percent hydrogen peroxide, and dry gas
meter) shown in Figure 6C-1. Connect the sampling train to the sample
bypass discharge vent. Record the dry gas meter reading before you begin
sampling. Simultaneously collect modified Method 6 and Method 6C
samples. Open the flow control valve in the modified Method 6 train as
you begin to sample with Method 6C. Adjust the Method 6 sampling rate to
1 liter per minute (.10 percent). The sampling time per run must be the
same as for Method 6 plus twice the average measurement system response
time. If your modified Method 6 train does not include a pump, you risk
biasing the results high if you over-pressurize the midget impingers and
cause a leak. You can reduce this risk by cautiously increasing the flow
rate as sampling begins.
b. After completing a run, record the final dry gas meter reading,
meter temperature, and barometric pressure. Recover and analyze the
contents of the midget impingers using the procedures in Method 6.
Determine the average gas concentration reported by Method 6C for the
run.
17.0 References
1. ``EPA Traceability Protocol for Assay and Certification of
Gaseous Calibration Standards'' September 1997 as amended, EPA-600/R-97/
121
18.0 Tables, Diagrams, Flowcharts, and Validation Data
[[Page 266]]
[GRAPHIC] [TIFF OMITTED] TR15MY06.000
Method 7--Determination of Nitrogen Oxide Emissions From Stationary
Sources
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1 and Method 5.
1.0 Scope and Application
1.1 Analytes.
------------------------------------------------------------------------
Analyte CAS No. Sensitivity
------------------------------------------------------------------------
Nitrogen oxides (NOX), as NO2,
including:
Nitric oxide (NO)............. 10102-43-9
Nitrogen dioxide (NO2)........ 10102-44-0 2-400 mg/dscm
------------------------------------------------------------------------
1.2 Applicability. This method is applicable for the measurement of
nitrogen oxides (NOX) emitted from stationary sources.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sample methods.
2.0 Summary of Method
A grab sample is collected in an evacuated flask containing a dilute
sulfuric acid-hydrogen peroxide absorbing solution, and the nitrogen
oxides, except nitrous oxide, are measured colorimetrically using the
phenoldisulfonic acid (PDS) procedure.
3.0 Definitions [Reserved]
4.0 Interferences
Biased results have been observed when sampling under conditions of
high sulfur dioxide concentrations. At or above 2100 ppm SO2,
use five times the H2O2 concentration of the
Method 7 absorbing solution. Laboratory tests have shown that high
concentrations of SO2 (about 2100 ppm) cause low results in
Method 7 and 7A. Increasing the H2O2 concentration
to five times the original concentration eliminates this bias. However,
when no SO2 is present, increasing the concentration by five
times results in a low bias.
[[Page 267]]
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user to establish appropriate safety and health practices and to
determine the applicability of regulatory limitations prior to
performing this test method.
5.2 Corrosive Reagents. The following reagents are hazardous.
Personal protective equipment and safe procedures are useful in
preventing chemical splashes. If contact occurs, immediately flush with
copious amounts of water for at least 15 minutes. Remove clothing under
shower and decontaminate. Treat residual chemical burns as thermal
burns.
5.2.1 Hydrogen Peroxide (H2O2). Irritating to
eyes, skin, nose, and lungs.
5.2.2 Phenoldisulfonic Acid. Irritating to eyes and skin.
5.2.3 Sodium Hydroxide (NaOH). Causes severe damage to eyes and
skin. Inhalation causes irritation to nose, throat, and lungs. Reacts
exothermically with limited amounts of water.
5.2.4 Sulfuric Acid (H2SO4). Rapidly
destructive to body tissue. Will cause third degree burns. Eye damage
may result in blindness. Inhalation may be fatal from spasm of the
larynx, usually within 30 minutes. May cause lung tissue damage with
edema. 1 mg/m\3\ for 8 hours will cause lung damage or, in higher
concentrations, death. Provide ventilation to limit inhalation. Reacts
violently with metals and organics.
5.2.5 Phenol. Poisonous and caustic. Do not handle with bare hands
as it is absorbed through the skin.
6.0 Equipment and Supplies
6.1 Sample Collection. A schematic of the sampling train used in
performing this method is shown in Figure 7-1. Other grab sampling
systems or equipment, capable of measuring sample volume to within 2.0
percent and collecting a sufficient sample volume to allow analytical
reproducibility to within 5 percent, will be considered acceptable
alternatives, subject to the approval of the Administrator. The
following items are required for sample collection:
6.1.1 Probe. Borosilicate glass tubing, sufficiently heated to
prevent water condensation and equipped with an in-stack or heated out-
of-stack filter to remove particulate matter (a plug of glass wool is
satisfactory for this purpose). Stainless steel or Teflon tubing may
also be used for the probe. Heating is not necessary if the probe
remains dry during the purging period.
6.1.2 Collection Flask. Two-liter borosilicate, round bottom flask,
with short neck and 24/40 standard taper opening, protected against
implosion or breakage.
6.1.3 Flask Valve. T-bore stopcock connected to a 24/40 standard
taper joint.
6.1.4 Temperature Gauge. Dial-type thermometer, or other temperature
gauge, capable of measuring 1 [deg]C (2 [deg]F) intervals from -5 to 50
[deg]C (23 to 122 [deg]F).
6.1.5 Vacuum Line. Tubing capable of withstanding a vacuum of 75 mm
(3 in.) Hg absolute pressure, with ``T'' connection and T-bore stopcock.
6.1.6 Vacuum Gauge. U-tube manometer, 1 meter (39 in.), with 1 mm
(0.04 in.) divisions, or other gauge capable of measuring pressure to
within 2.5 mm (0.10 in.) Hg.
6.1.7 Pump. Capable of evacuating the collection flask to a pressure
equal to or less than 75 mm (3 in.) Hg absolute.
6.1.8 Squeeze Bulb. One-way.
6.1.9 Volumetric Pipette. 25-ml.
6.1.10 Stopcock and Ground Joint Grease. A high-vacuum, high-
temperature chlorofluorocarbon grease is required. Halocarbon 25-5S has
been found to be effective.
6.1.11 Barometer. Mercury, aneroid, or other barometer capable of
measuring atmospheric pressure to within 2.5 mm (0.1 in.) Hg. See note
in Method 5, section 6.1.2.
6.2 Sample Recovery. The following items are required for sample
recovery:
6.2.1 Graduated Cylinder. 50-ml with 1 ml divisions.
6.2.2 Storage Containers. Leak-free polyethylene bottles.
6.2.3 Wash Bottle. Polyethylene or glass.
6.2.4 Glass Stirring Rod.
6.2.5 Test Paper for Indicating pH. To cover the pH range of 7 to
14.
6.3 Analysis. The following items are required for analysis:
6.3.1 Volumetric Pipettes. Two 1-ml, two 2-ml, one 3-ml, one 4-ml,
two 10-ml, and one 25-ml for each sample and standard.
6.3.2 Porcelain Evaporating Dishes. 175- to 250-ml capacity with lip
for pouring, one for each sample and each standard. The Coors No. 45006
(shallowform, 195-ml) has been found to be satisfactory. Alternatively,
polymethyl pentene beakers (Nalge No. 1203, 150-ml), or glass beakers
(150-ml) may be used. When glass beakers are used, etching of the
beakers may cause solid matter to be present in the analytical step; the
solids should be removed by filtration.
6.3.3 Steam Bath. Low-temperature ovens or thermostatically
controlled hot plates kept below 70 [deg]C (160 [deg]F) are acceptable
alternatives.
6.3.4 Dropping Pipette or Dropper. Three required.
6.3.5 Polyethylene Policeman. One for each sample and each standard.
6.3.6 Graduated Cylinder. 100-ml with 1-ml divisions.
[[Page 268]]
6.3.7 Volumetric Flasks. 50-ml (one for each sample and each
standard), 100-ml (one for each sample and each standard, and one for
the working standard KNO3 solution), and 1000-ml (one).
6.3.8 Spectrophotometer. To measure at 410 nm.
6.3.9 Graduated Pipette. 10-ml with 0.1-ml divisions.
6.3.10 Test Paper for Indicating pH. To cover the pH range of 7 to
14.
6.3.11 Analytical Balance. To measure to within 0.1 mg.
7.0 Reagents and Standards
Unless otherwise indicated, it is intended that all reagents conform
to the specifications established by the Committee on Analytical
Reagents of the American Chemical Society, where such specifications are
available; otherwise, use the best available grade.
7.1 Sample Collection. The following reagents are required for
sampling:
7.1.1 Water. Deionized distilled to conform to ASTM D 1193-77 or 91
Type 3 (incorporated by reference--see Sec. 60.17). The
KMnO4 test for oxidizable organic matter may be omitted when
high concentrations of organic matter are not expected to be present.
7.1.2 Absorbing Solution. Cautiously add 2.8 ml concentrated
H2SO4 to a 1-liter flask partially filled with
water. Mix well, and add 6 ml of 3 percent hydrogen peroxide, freshly
prepared from 30 percent hydrogen peroxide solution. Dilute to 1 liter
of water and mix well. The absorbing solution should be used within 1
week of its preparation. Do not expose to extreme heat or direct
sunlight.
7.2 Sample Recovery. The following reagents are required for sample
recovery:
7.2.1 Water. Same as in 7.1.1.
7.2.2 Sodium Hydroxide, 1 N. Dissolve 40 g NaOH in water, and dilute
to 1 liter.
7.3 Analysis. The following reagents and standards are required for
analysis:
7.3.1 Water. Same as in 7.1.1.
7.3.2 Fuming Sulfuric Acid. 15 to 18 percent by weight free sulfur
trioxide. HANDLE WITH CAUTION.
7.3.3 Phenol. White solid.
7.3.4 Sulfuric Acid. Concentrated, 95 percent minimum assay.
7.3.5 Potassium Nitrate (KNO3). Dried at 105 to 110
[deg]C (221 to 230 [deg]F) for a minimum of 2 hours just prior to
preparation of standard solution.
7.3.6 Standard KNO3 Solution. Dissolve exactly 2.198 g of
dried KNO3 in water, and dilute to 1 liter with water in a
1000-ml volumetric flask.
7.3.7 Working Standard KNO3 Solution. Dilute 10 ml of the
standard solution to 100 ml with water. One ml of the working standard
solution is equivalent to 100 [micro]g nitrogen dioxide
(NO2).
7.3.8 Phenoldisulfonic Acid Solution. Dissolve 25 g of pure white
phenol solid in 150 ml concentrated sulfuric acid on a steam bath. Cool,
add 75 ml fuming sulfuric acid (15 to 18 percent by weight free sulfur
trioxide--HANDLE WITH CAUTION), and heat at 100 [deg]C (212 [deg]F) for
2 hours. Store in a dark, stoppered bottle.
7.3.9 Concentrated Ammonium Hydroxide.
8.0 Sample Collection, Preservation, Storage and Transport
8.1 Sample Collection.
8.1.1 Flask Volume. The volume of the collection flask and flask
valve combination must be known prior to sampling. Assemble the flask
and flask valve, and fill with water to the stopcock. Measure the volume
of water to 10 ml. Record this volume on the
flask.
8.1.2 Pipette 25 ml of absorbing solution into a sample flask,
retaining a sufficient quantity for use in preparing the calibration
standards. Insert the flask valve stopper into the flask with the valve
in the ``purge'' position. Assemble the sampling train as shown in
Figure 7-1, and place the probe at the sampling point. Make sure that
all fittings are tight and leak-free, and that all ground glass joints
have been greased properly with a high-vacuum, high temperature
chlorofluorocarbon-based stopcock grease. Turn the flask valve and the
pump valve to their ``evacuate'' positions. Evacuate the flask to 75 mm
(3 in.) Hg absolute pressure, or less. Evacuation to a pressure
approaching the vapor pressure of water at the existing temperature is
desirable. Turn the pump valve to its ``vent'' position, and turn off
the pump. Check for leakage by observing the manometer for any pressure
fluctuation. (Any variation greater than 10 mm (0.4 in.) Hg over a
period of 1 minute is not acceptable, and the flask is not to be used
until the leakage problem is corrected. Pressure in the flask is not to
exceed 75 mm (3 in.) Hg absolute at the time sampling is commenced.)
Record the volume of the flask and valve (Vf), the flask
temperature (Ti), and the barometric pressure. Turn the flask
valve counterclockwise to its ``purge'' position, and do the same with
the pump valve. Purge the probe and the vacuum tube using the squeeze
bulb. If condensation occurs in the probe and the flask valve area, heat
the probe, and purge until the condensation disappears. Next, turn the
pump valve to its ``vent'' position. Turn the flask valve clockwise to
its ``evacuate'' position, and record the difference in the mercury
levels in the manometer. The absolute internal pressure in the flask
(Pi) is equal to the barometric pressure less the manometer
reading. Immediately turn the flask valve to the ``sample'' position,
and permit the gas to enter the flask until pressures in the flask and
sample line (i.e., duct, stack) are equal. This will usually require
about 15 seconds; a longer period indicates a plug in the probe, which
must be
[[Page 269]]
corrected before sampling is continued. After collecting the sample,
turn the flask valve to its ``purge'' position, and disconnect the flask
from the sampling train.
8.1.3 Shake the flask for at least 5 minutes.
8.1.4 If the gas being sampled contains insufficient oxygen for the
conversion of NO to NO2 (e.g., an applicable subpart of the
standards may require taking a sample of a calibration gas mixture of NO
in N2), then introduce oxygen into the flask to permit this
conversion. Oxygen may be introduced into the flask by one of three
methods: (1) Before evacuating the sampling flask, flush with pure
cylinder oxygen, then evacuate flask to 75 mm (3 in.) Hg absolute
pressure or less; or (2) inject oxygen into the flask after sampling; or
(3) terminate sampling with a minimum of 50 mm (2 in.) Hg vacuum
remaining in the flask, record this final pressure, and then vent the
flask to the atmosphere until the flask pressure is almost equal to
atmospheric pressure.
8.2 Sample Recovery. Let the flask sit for a minimum of 16 hours,
and then shake the contents for 2 minutes.
8.2.1 Connect the flask to a mercury filled U-tube manometer. Open
the valve from the flask to the manometer, and record the flask
temperature (Tf), the barometric pressure, and the difference
between the mercury levels in the manometer. The absolute internal
pressure in the flask (Pf) is the barometric pressure less
the manometer reading. Transfer the contents of the flask to a leak-free
polyethylene bottle. Rinse the flask twice with 5 ml portions of water,
and add the rinse water to the bottle. Adjust the pH to between 9 and 12
by adding 1 N NaOH, dropwise (about 25 to 35 drops). Check the pH by
dipping a stirring rod into the solution and then touching the rod to
the pH test paper. Remove as little material as possible during this
step. Mark the height of the liquid level so that the container can be
checked for leakage after transport. Label the container to identify
clearly its contents. Seal the container for shipping.
9.0 Quality Control
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
10.1.......................... Spectrophotometer Ensure linearity of
calibration. spectrophotometer
response to
standards.
------------------------------------------------------------------------
10.0 Calibration and Standardization
10.1 Spectrophotometer.
10.1.1 Optimum Wavelength Determination.
10.1.1.1 Calibrate the wavelength scale of the spectrophotometer
every 6 months. The calibration may be accomplished by using an energy
source with an intense line emission such as a mercury lamp, or by using
a series of glass filters spanning the measuring range of the
spectrophotometer. Calibration materials are available commercially and
from the National Institute of Standards and Technology. Specific
details on the use of such materials should be supplied by the vendor;
general information about calibration techniques can be obtained from
general reference books on analytical chemistry. The wavelength scale of
the spectrophotometer must read correctly within 5 nm at all calibration
points; otherwise, repair and recalibrate the spectrophotometer. Once
the wavelength scale of the spectrophotometer is in proper calibration,
use 410 nm as the optimum wavelength for the measurement of the
absorbance of the standards and samples.
10.1.1.2 Alternatively, a scanning procedure may be employed to
determine the proper measuring wavelength. If the instrument is a
double-beam spectrophotometer, scan the spectrum between 400 and 415 nm
using a 200 [micro]g NO2 standard solution in the sample cell
and a blank solution in the reference cell. If a peak does not occur,
the spectrophotometer is probably malfunctioning and should be repaired.
When a peak is obtained within the 400 to 415 nm range, the wavelength
at which this peak occurs shall be the optimum wavelength for the
measurement of absorbance of both the standards and the samples. For a
single-beam spectrophotometer, follow the scanning procedure described
above, except scan separately the blank and standard solutions. The
optimum wavelength shall be the wavelength at which the maximum
difference in absorbance between the standard and the blank occurs.
10.1.2 Determination of Spectrophotometer Calibration Factor
Kc. Add 0 ml, 2.0 ml, 4.0 ml, 6.0 ml, and 8.0 ml of the
KNO3 working standard solution (1 ml = 100 [micro]g
NO2) to a series of five 50-ml volumetric flasks. To each
flask, add 25 ml of absorbing solution and 10 ml water. Add 1 N NaOH to
each flask until the pH is between 9 and 12 (about 25 to 35 drops).
Dilute to the mark with water. Mix thoroughly, and pipette a 25-ml
aliquot of each solution into a separate porcelain evaporating dish.
Beginning with the evaporation step, follow the analysis procedure of
section 11.2 until the solution has been transferred to the 100-ml
volumetric flask and diluted to the mark. Measure the absorbance of each
solution at the optimum wavelength as determined in section 10.1.1. This
calibration procedure must be repeated on each day that samples are
analyzed. Calculate the spectrophotometer calibration factor as shown in
section 12.2.
[[Page 270]]
10.1.3 Spectrophotometer Calibration Quality Control. Multiply the
absorbance value obtained for each standard by the Kc factor
(reciprocal of the least squares slope) to determine the distance each
calibration point lies from the theoretical calibration line. The
difference between the calculated concentration values and the actual
concentrations (i.e., 100, 200, 300, and 400 [micro]g NO2)
should be less than 7 percent for all standards.
10.2 Barometer. Calibrate against a mercury barometer or NIST-
traceable barometer prior to the field test.
10.3 Temperature Gauge. Calibrate dial thermometers against mercury-
in-glass thermometers. An alternative mercury-free thermometer may be
used if the thermometer is, at a minimum, equivalent in terms of
performance or suitably effective for the specific temperature
measurement application.
10.4 Vacuum Gauge. Calibrate mechanical gauges, if used, against a
mercury manometer such as that specified in section 6.1.6.
10.5 Analytical Balance. Calibrate against standard weights.
11.0 Analytical Procedures
11.1 Sample Loss Check. Note the level of the liquid in the
container, and confirm whether any sample was lost during shipment. Note
this on the analytical data sheet. If a noticeable amount of leakage has
occurred, either void the sample or use methods, subject to the approval
of the Administrator, to correct the final results.
11.2 Sample Preparation. Immediately prior to analysis, transfer the
contents of the shipping container to a 50 ml volumetric flask, and
rinse the container twice with 5 ml portions of water. Add the rinse
water to the flask, and dilute to mark with water; mix thoroughly.
Pipette a 25-ml aliquot into the porcelain evaporating dish. Return any
unused portion of the sample to the polyethylene storage bottle.
Evaporate the 25-ml aliquot to dryness on a steam bath, and allow to
cool. Add 2 ml phenoldisulfonic acid solution to the dried residue, and
triturate thoroughly with a polyethylene policeman. Make sure the
solution contacts all the residue. Add 1 ml water and 4 drops of
concentrated sulfuric acid. Heat the solution on a steam bath for 3
minutes with occasional stirring. Allow the solution to cool, add 20 ml
water, mix well by stirring, and add concentrated ammonium hydroxide,
dropwise, with constant stirring, until the pH is 10 (as determined by
pH paper). If the sample contains solids, these must be removed by
filtration (centrifugation is an acceptable alternative, subject to the
approval of the Administrator) as follows: Filter through Whatman No. 41
filter paper into a 100-ml volumetric flask. Rinse the evaporating dish
with three 5-ml portions of water. Filter these three rinses. Wash the
filter with at least three 15-ml portions of water. Add the filter
washings to the contents of the volumetric flask, and dilute to the mark
with water. If solids are absent, the solution can be transferred
directly to the 100-ml volumetric flask and diluted to the mark with
water.
11.3 Sample Analysis. Mix the contents of the flask thoroughly, and
measure the absorbance at the optimum wavelength used for the standards
(section 10.1.1), using the blank solution as a zero reference. Dilute
the sample and the blank with equal volumes of water if the absorbance
exceeds A4, the absorbance of the 400-[micro]g NO2
standard (see section 10.1.3).
12.0 Data Analysis and Calculations
Carry out the calculations, retaining at least one extra significant
figure beyond that of the acquired data. Round off figures after final
calculations.
12.1 12.1 Nomenclature
A = Absorbance of sample.
A1 = Absorbance of the 100-[micro]g NO2 standard.
A2 = Absorbance of the 200-[micro]g NO2 standard.
A3 = Absorbance of the 300-[micro]g NO2 standard.
A4 = Absorbance of the 400-[micro]g NO2 standard.
C = Concentration of NOX as NO2, dry basis,
corrected to standard conditions, mg/dsm\3\ (lb/dscf).
F = Dilution factor (i.e., 25/5, 25/10, etc., required only if sample
dilution was needed to reduce the absorbance into the range of
the calibration).
Kc = Spectrophotometer calibration factor.
M = Mass of NOX as NO2 in gas sample, [micro]g.
Pf = Final absolute pressure of flask, mm Hg (in. Hg).
Pi = Initial absolute pressure of flask, mm Hg (in. Hg).
Pstd = Standard absolute pressure, 760 mm Hg (29.92 in. Hg).
Tf = Final absolute temperature of flask, [deg]K ([deg]R).
Ti = Initial absolute temperature of flask, [deg]K ([deg]R).
Tstd = Standard absolute temperature, 293 [deg]K (528[deg]R).
Vsc = Sample volume at standard conditions (dry basis), ml.
Vf = Volume of flask and valve, ml.
Va = Volume of absorbing solution, 25 ml.
12.2 Spectrophotometer Calibration Factor.
[[Page 271]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.200
12.3 Sample Volume, Dry Basis, Corrected to Standard Conditions.
[GRAPHIC] [TIFF OMITTED] TR17OC00.201
Where:
K1 = 0.3858 [deg]K/mm Hg for metric units,
K1 = 17.65 [deg]R/in. Hg for English units.
12.4 Total [micro]g NO2 per sample.
[GRAPHIC] [TIFF OMITTED] TR17OC00.202
Where:
2 = 50/25, the aliquot factor.
Note: If other than a 25-ml aliquot is used for analysis, the factor
2 must be replaced by a corresponding factor.
12.5 Sample Concentration, Dry Basis, Corrected to Standard
Conditions.
[GRAPHIC] [TIFF OMITTED] TR17OC00.203
Where:
K2 = 10\3\ (mg/m\3\)/([micro]g/ml) for metric units,
K2 = 6.242 x 10-5 (lb/scf)/([micro]g/ml) for
English units.
13.0 Method Performance
13.1 Range. The analytical range of the method has been determined
to be 2 to 400 milligrams NOX (as NO2) per dry
standard cubic meter, without having to dilute the sample.
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
1. Standard Methods of Chemical Analysis. 6th ed. New York, D. Van
Nostrand Co., Inc. 1962. Vol. 1, pp. 329-330.
2. Standard Method of Test for Oxides of Nitrogen in Gaseous
Combustion Products (Phenoldisulfonic Acid Procedure). In: 1968 Book of
ASTM Standards, Part 26. Philadelphia, PA. 1968. ASTM Designation D
1608-60, pp. 725-729.
3. Jacob, M.B. The Chemical Analysis of Air Pollutants. New York.
Interscience Publishers, Inc. 1960. Vol. 10, pp. 351-356.
4. Beatty, R.L., L.B. Berger, and H.H. Schrenk. Determination of
Oxides of Nitrogen by the Phenoldisulfonic Acid Method. Bureau of Mines,
U.S. Dept. of Interior. R.I. 3687. February 1943.
5. Hamil, H.F. and D.E. Camann. Collaborative Study of Method for
the Determination of Nitrogen Oxide Emissions from Stationary Sources
(Fossil Fuel-Fired Steam Generators). Southwest Research Institute
Report for Environmental Protection Agency. Research Triangle Park, NC.
October 5, 1973.
6. Hamil, H.F. and R.E. Thomas. Collaborative Study of Method for
the Determination of Nitrogen Oxide Emissions from Stationary Sources
(Nitric Acid Plants). Southwest Research Institute Report for
Environmental Protection Agency. Research Triangle Park, NC. May 8,
1974.
7. Stack Sampling Safety Manual (Draft). U.S. Environmental
Protection Agency, Office of Air Quality Planning and Standards,
Research Triangle Park, NC. September 1978.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
[[Page 272]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.205
Method 7A--Determination of Nitrogen Oxide Emissions From Stationary
Sources (Ion Chromatographic Method)
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 3, Method 5, and
Method 7.
1.0 Scope and Application
1.1 Analytes.
[[Page 273]]
------------------------------------------------------------------------
Analyte CAS No. Sensitivity
------------------------------------------------------------------------
Nitrogen oxides (NOX), as NO2,
including:
Nitric oxide (NO)............. 10102-43-9 ....................
Nitrogen dioxide (NO2)........ 10102-44-0 65-655 ppmv
------------------------------------------------------------------------
1.2 Applicability. This method is applicable for the determination
of NOX emissions from stationary sources.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
A grab sample is collected in an evacuated flask containing a dilute
sulfuric acid-hydrogen peroxide absorbing solution. The nitrogen oxides,
excluding nitrous oxide (N2O), are oxidized to nitrate and
measured by ion chromatography.
3.0 Definitions [Reserved]
4.0 Interferences
Biased results have been observed when sampling under conditions of
high sulfur dioxide concentrations. At or above 2100 ppm SO2,
use five times the H2O2 concentration of the
Method 7 absorbing solution. Laboratory tests have shown that high
concentrations of SO2 (about 2100 ppm) cause low results in
Method 7 and 7A. Increasing the H2O2 concentration
to five times the original concentration eliminates this bias. However,
when no SO2 is present, increasing the concentration by five
times results in a low bias.
5.0 Safety
5.1 This method may involve hazardous materials, operations, and
equipment. This test method may not address all of the safety problems
associated with its use. It is the responsibility of the user of this
test method to establish appropriate safety and health practices and to
determine the applicability of regulatory limitations prior to
performing this test method.
5.2 Corrosive reagents. The following reagents are hazardous.
Personal protective equipment and safe procedures are useful in
preventing chemical splashes. If contact occurs, immediately flush with
copious amounts of water at least 15 minutes. Remove clothing under
shower and decontaminate. Treat residual chemical burns as thermal
burns.
5.2.1 Hydrogen Peroxide (H2O2). Irritating to
eyes, skin, nose, and lungs.
5.2.2 Sulfuric Acid (H2SO4). Rapidly
destructive to body tissue. Will cause third degree burns. Eye damage
may result in blindness. Inhalation may be fatal from spasm of the
larynx, usually within 30 minutes. May cause lung tissue damage with
edema. 3 mg/m\3\ will cause lung damage in uninitiated. 1 mg/m\3\ for 8
hours will cause lung damage or, in higher concentrations, death.
Provide ventilation to limit inhalation. Reacts violently with metals
and organics.
6.0 Equipment and Supplies
6.1 Sample Collection. Same as in Method 7, section 6.1.
6.2 Sample Recovery. Same as in Method 7, section 6.2, except the
stirring rod and pH paper are not needed.
6.3 Analysis. For the analysis, the following equipment and supplies
are required. Alternative instrumentation and procedures will be allowed
provided the calibration precision requirement in section 10.1.2 can be
met.
6.3.1 Volumetric Pipets. Class A;1-, 2-, 4-, 5-ml (two for the set
of standards and one per sample), 6-, 10-, and graduated 5-ml sizes.
6.3.2 Volumetric Flasks. 50-ml (two per sample and one per
standard), 200-ml, and 1-liter sizes.
6.3.3 Analytical Balance. To measure to within 0.1 mg.
6.3.4 Ion Chromatograph. The ion chromatograph should have at least
the following components:
6.3.4.1 Columns. An anion separation or other column capable of
resolving the nitrate ion from sulfate and other species present and a
standard anion suppressor column (optional). Suppressor columns are
produced as proprietary items; however, one can be produced in the
laboratory using the resin available from BioRad Company, 32nd and
Griffin Streets, Richmond, California. Peak resolution can be optimized
by varying the eluent strength or column flow rate, or by experimenting
with alternative columns that may offer more efficient separation. When
using guard columns with the stronger reagent to protect the separation
column, the analyst should allow rest periods between injection
intervals to purge possible sulfate buildup in the guard column.
6.3.4.2 Pump. Capable of maintaining a steady flow as required by
the system.
6.3.4.3 Flow Gauges. Capable of measuring the specified system flow
rate.
6.3.4.4 Conductivity Detector.
6.3.4.5 Recorder. Compatible with the output voltage range of the
detector.
[[Page 274]]
7.0 Reagents and Standards
Unless otherwise indicated, it is intended that all reagents conform
to the specifications established by the Committee on Analytical
Reagents of the American Chemical Society, where such specifications are
available; otherwise, use the best available grade.
7.1 Sample Collection. Same as Method 7, section 7.1.
7.2 Sample Recovery. Same as Method 7, section 7.1.1.
7.3 Analysis. The following reagents and standards are required for
analysis:
7.3.1 Water. Same as Method 7, section 7.1.1.
7.3.2 Stock Standard Solution, 1 mg NO2/ml. Dry an
adequate amount of sodium nitrate (NaNO3) at 105 to 110
[deg]C (221 to 230 [deg]F) for a minimum of 2 hours just before
preparing the standard solution. Then dissolve exactly 1.847 g of dried
NaNO3 in water, and dilute to l liter in a volumetric flask.
Mix well. This solution is stable for 1 month and should not be used
beyond this time.
7.3.3 Working Standard Solution, 25 [micro]g/ml. Dilute 5 ml of the
standard solution to 200 ml with water in a volumetric flask, and mix
well.
7.3.4 Eluent Solution. Weigh 1.018 g of sodium carbonate
(Na2CO3) and 1.008 g of sodium bicarbonate
(NaHCO3), and dissolve in 4 liters of water. This solution is
0.0024 M Na2CO3/0.003 M NaHCO3. Other
eluents appropriate to the column type and capable of resolving nitrate
ion from sulfate and other species present may be used.
8.0 Sample Collection, Preservation, Storage, and Transport
8.1 Sampling. Same as in Method 7, section 8.1.
8.2 Sample Recovery. Same as in Method 7, section 8.2, except delete
the steps on adjusting and checking the pH of the sample. Do not store
the samples more than 4 days between collection and analysis.
9.0 Quality Control
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
10.1.......................... Ion Ensure linearity of
chromatographn ion chromatograph
calibration. response to
standards.
------------------------------------------------------------------------
10.0 Calibration and Standardizations
10.1 Ion Chromatograph.
10.1.1 Determination of Ion Chromatograph Calibration Factor S.
Prepare a series of five standards by adding 1.0, 2.0, 4.0, 6.0, and
10.0 ml of working standard solution (25 [micro]g/ml) to a series of
five 50-ml volumetric flasks. (The standard masses will equal 25, 50,
100, 150, and 250 [micro]g.) Dilute each flask to the mark with water,
and mix well. Analyze with the samples as described in section 11.2, and
subtract the blank from each value. Prepare or calculate a linear
regression plot of the standard masses in [micro]g (x-axis) versus their
peak height responses in millimeters (y-axis). (Take peak height
measurements with symmetrical peaks; in all other cases, calculate peak
areas.) From this curve, or equation, determine the slope, and calculate
its reciprocal to denote as the calibration factor, S.
10.1.2 Ion Chromatograph Calibration Quality Control. If any point
on the calibration curve deviates from the line by more than 7 percent
of the concentration at that point, remake and reanalyze that standard.
This deviation can be determined by multiplying S times the peak height
response for each standard. The resultant concentrations must not differ
by more than 7 percent from each known standard mass (i.e., 25, 50, 100,
150, and 250 [micro]g).
10.2 Conductivity Detector. Calibrate according to manufacturer's
specifications prior to initial use.
10.3 Barometer. Calibrate against a mercury barometer.
10.4 Temperature Gauge. Calibrate dial thermometers against mercury-
in-glass thermometers. An alternative mercury-free thermometer may be
used if the thermometer is, at a minimum, equivalent in terms of
performance or suitably effective for the specific temperature
measurement application.
10.5 Vacuum Gauge. Calibrate mechanical gauges, if used, against a
mercury manometer such as that specified in section 6.1.6 of Method 7.
10.6 Analytical Balance. Calibrate against standard weights.
11.0 Analytical Procedures
11.1 Sample Preparation.
11.1.1 Note on the analytical data sheet, the level of the liquid in
the container, and whether any sample was lost during shipment. If a
noticeable amount of leakage has occurred, either void the sample or use
methods, subject to the approval of the Administrator, to correct the
final results. Immediately before analysis, transfer the contents of the
shipping container to a 50-ml volumetric flask, and rinse the container
twice with 5 ml portions of water. Add the rinse water to the flask, and
dilute to the mark with water. Mix thoroughly.
11.1.2 Pipet a 5-ml aliquot of the sample into a 50-ml volumetric
flask, and dilute to the mark with water. Mix thoroughly. For each set
of determinations, prepare a reagent
[[Page 275]]
blank by diluting 5 ml of absorbing solution to 50 ml with water.
(Alternatively, eluent solution may be used instead of water in all
sample, standard, and blank dilutions.)
11.2 Analysis.
11.2.1 Prepare a standard calibration curve according to section
10.1.1. Analyze the set of standards followed by the set of samples
using the same injection volume for both standards and samples. Repeat
this analysis sequence followed by a final analysis of the standard set.
Average the results. The two sample values must agree within 5 percent
of their mean for the analysis to be valid. Perform this duplicate
analysis sequence on the same day. Dilute any sample and the blank with
equal volumes of water if the concentration exceeds that of the highest
standard.
11.2.2 Document each sample chromatogram by listing the following
analytical parameters: injection point, injection volume, nitrate and
sulfate retention times, flow rate, detector sensitivity setting, and
recorder chart speed.
12.0 Data Analysis and Calculations
Carry out the calculations, retaining at least one extra significant
figure beyond that of the acquired data. Round off figures after final
calculations.
12.1 Sample Volume. Calculate the sample volume Vsc (in ml), on a
dry basis, corrected to standard conditions, using Equation 7-2 of
Method 7.
12.2 Sample Concentration of NOX as NO2.
12.2.1 Calculate the sample concentration C (in mg/dscm) as follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.206
Where:
H = Sample peak height, mm.
S = Calibration factor, [micro]g/mm.
F = Dilution factor (required only if sample dilution was needed to
reduce the concentration into the range of calibration),
dimensionless.
10\4\ = 1:10 dilution times conversion factor of: (mg/10\3\
[micro]g)(10\6\ ml/m\3\).
12.2.2 If desired, the concentration of NO2 may be
calculated as ppm NO2 at standard conditions as follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.207
Where:
0.5228 = ml/mg NO2.
13.0 Method Performance
13.1 Range. The analytical range of the method is from 125 to 1250
mg NOX/m\3\ as NO2 (65 to 655 ppmv), and higher
concentrations may be analyzed by diluting the sample. The lower
detection limit is approximately 19 mg/m\3\ (10 ppmv), but may vary
among instruments.
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
1. Mulik, J.D., and E. Sawicki. Ion Chromatographic Analysis of
Environmental Pollutants. Ann Arbor, Ann Arbor Science Publishers, Inc.
Vol. 2, 1979.
2. Sawicki, E., J.D. Mulik, and E. Wittgenstein. Ion Chromatographic
Analysis of Environmental Pollutants. Ann Arbor, Ann Arbor Science
Publishers, Inc. Vol. 1. 1978.
3. Siemer, D.D. Separation of Chloride and Bromide from Complex
Matrices Prior to Ion Chromatographic Determination. Anal. Chem.
52(12):1874-1877. October 1980.
4. Small, H., T.S. Stevens, and W.C. Bauman. Novel Ion Exchange
Chromatographic Method Using Conductimetric Determination. Anal. Chem.
47(11):1801. 1975.
5. Yu, K.K., and P.R. Westlin. Evaluation of Reference Method 7
Flask Reaction Time. Source Evaluation Society Newsletter. 4(4).
November 1979. 10 pp.
6. Stack Sampling Safety Manual (Draft). U.S. Environmental
Protection Agency, Office of Air Quality Planning and Standard, Research
Triangle Park, NC. September 1978.
17.0 Tables, Diagrams, Flowcharts, and Validation Data [Reserved]
Method 7B--Determination of Nitrogen Oxide Emissions From Stationary
Sources (Ultraviolet Spectrophotometric Method)
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 5, and Method 7.
1.0 Scope and Application
1.1 Analytes.
------------------------------------------------------------------------
Analyte CAS No. Sensitivity
------------------------------------------------------------------------
Nitrogen oxides (NOX), as NO2,
including:
[[Page 276]]
Nitric oxide (NO)............. 10102-43-9
Nitrogen dioxide (NO2)........ 10102-44-0 30-786 ppmv
------------------------------------------------------------------------
1.2 Applicability. This method is applicable for the determination
of NOX emissions from nitric acid plants.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
2.1 A grab sample is collected in an evacuated flask containing a
dilute sulfuric acid-hydrogen peroxide absorbing solution; the
NOX, excluding nitrous oxide (N2O), are measured
by ultraviolet spectrophotometry.
3.0 Definition [Reserved]
4.0 Interferences [Reserved]
5.0 Safety
5.1 This method may involve hazardous materials, operations, and
equipment. This test method may not address all of the safety problems
associated with its use. It is the responsibility of the user of this
test method to establish appropriate safety and health practices and to
determine the applicability of regulatory limitations prior to
performing this test method.
5.2 Corrosive reagents. The following reagents are hazardous.
Personal protective equipment and safe procedures are useful in
preventing chemical splashes. If contact occurs, immediately flush with
copious amounts of water at least 15 minutes. Remove clothing under
shower and decontaminate. Treat residual chemical burn as thermal burn.
5.2.1 Hydrogen Peroxide (H2O2). Irritating to
eyes, skin, nose, and lungs.
5.2.2 Sodium Hydroxide (NaOH). Causes severe damage to eyes and
skin. Inhalation causes irritation to nose, throat, and lungs. Reacts
exothermically with limited amounts of water.
5.2.3 Sulfuric Acid (H2SO4). Rapidly
destructive to body tissue. Will cause third degree burns. Eye damage
may result in blindness. Inhalation may be fatal from spasm of the
larynx, usually within 30 minutes. May cause lung tissue damage with
edema. 3 mg/m\3\ will cause lung damage in uninitiated. 1 mg/m\3\ for 8
hours will cause lung damage or, in higher concentrations, death.
Provide ventilation to limit inhalation. Reacts violently with metals
and organics.
6.0 Equipment and Supplies
6.1 Sample Collection. Same as Method 7, section 6.1.
6.2 Sample Recovery. The following items are required for sample
recovery:
6.2.1 Wash Bottle. Polyethylene or glass.
6.2.2 Volumetric Flasks. 100-ml (one for each sample).
6.3 Analysis. The following items are required for analysis:
6.3.1 Volumetric Pipettes. 5-, 10-, 15-, and 20-ml to make standards
and sample dilutions.
6.3.2 Volumetric Flasks. 1000- and 100-ml for preparing standards
and dilution of samples.
6.3.3 Spectrophotometer. To measure ultraviolet absorbance at 210
nm.
6.3.4 Analytical Balance. To measure to within 0.1 mg.
7.0 Reagents and Standards
Note: Unless otherwise indicated, all reagents are to conform to the
specifications established by the Committee on Analytical Reagents of
the American Chemical Society, where such specifications are available.
Otherwise, use the best available grade.
7.1 Sample Collection. Same as Method 7, section 7.1. It is
important that the amount of hydrogen peroxide in the absorbing solution
not be increased. Higher concentrations of peroxide may interfere with
sample analysis.
7.2 Sample Recovery. Same as Method 7, section 7.2.
7.3 Analysis. Same as Method 7, sections 7.3.1, 7.3.3, and 7.3.4,
with the addition of the following:
7.3.1 Working Standard KNO3 Solution. Dilute 10 ml of the
standard solution to 1000 ml with water. One milliliter of the working
standard is equivalent to 10 [micro]g NO2.
8.0 Sample Collection, Preservation, Storage, and Transport
8.1 Sample Collection. Same as Method 7, section 8.1.
8.2 Sample Recovery.
8.2.1 Let the flask sit for a minimum of 16 hours, and then shake
the contents for 2 minutes.
8.2.2 Connect the flask to a mercury filled U-tube manometer. Open
the valve from the flask to the manometer, and record the flask
temperature (Tf), the barometric pressure, and the difference
between the mercury levels in the manometer. The absolute internal
pressure in the flask (Pf) is the barometric pressure less
the manometer reading.
8.2.3 Transfer the contents of the flask to a leak-free wash bottle.
Rinse the flask three times with 10-ml portions of water, and add
[[Page 277]]
to the bottle. Mark the height of the liquid level so that the container
can be checked for leakage after transport. Label the container to
identify clearly its contents. Seal the container for shipping.
9.0 Quality Control
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
10.1.......................... Spectrophotometer Ensures linearity of
calibration. spectrophotometer
response to
standards.
------------------------------------------------------------------------
10.0 Calibration and Standardizations
Same as Method 7, sections 10.2 through 10.5, with the addition of
the following:
10.1 Determination of Spectrophotometer Standard Curve. Add 0 ml, 5
ml, 10 ml, 15 ml, and 20 ml of the KNO3 working standard
solution (1 ml = 10 [micro]g NO2) to a series of five 100-ml
volumetric flasks. To each flask, add 5 ml of absorbing solution. Dilute
to the mark with water. The resulting solutions contain 0.0, 50, 100,
150, and 200 [micro]g NO2, respectively. Measure the
absorbance by ultraviolet spectrophotometry at 210 nm, using the blank
as a zero reference. Prepare a standard curve plotting absorbance vs.
[micro]g NO2.
Note: If other than a 20-ml aliquot of sample is used for analysis,
then the amount of absorbing solution in the blank and standards must be
adjusted such that the same amount of absorbing solution is in the blank
and standards as is in the aliquot of sample used.
10.1.1 Calculate the spectrophotometer calibration factor as
follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.208
Where:
Mi = Mass of NO2 in standard i, [micro]g.
Ai = Absorbance of NO2 standard i.
n = Total number of calibration standards.
10.1.2 For the set of calibration standards specified here, Equation
7B-1 simplifies to the following:
[GRAPHIC] [TIFF OMITTED] TR17OC00.209
10.2 Spectrophotometer Calibration Quality Control. Multiply the
absorbance value obtained for each standard by the Kc factor
(reciprocal of the least squares slope) to determine the distance each
calibration point lies from the theoretical calibration line. The
difference between the calculated concentration values and the actual
concentrations (i.e., 50, 100, 150, and 200 [micro]g NO2)
should be less than 7 percent for all standards.
11.0 Analytical Procedures
11.1 Sample Loss Check. Note the level of the liquid in the
container, and confirm whether any sample was lost during shipment. Note
this on the analytical data sheet. If a noticeable amount of leakage has
occurred, either void the sample or use methods, subject to the approval
of the Administrator, to correct the final results.
11.2 Sample Preparation. Immediately prior to analysis, transfer the
contents of the shipping container to a 100-ml volumetric flask, and
rinse the container twice with 5-ml portions of water. Add the rinse
water to the flask, and dilute to mark with water.
11.3 Sample Analysis. Mix the contents of the flask thoroughly and
pipette a 20 ml-aliquot of sample into a 100-ml volumetric flask. Dilute
to the mark with water. Using the blank as zero reference, read the
absorbance of the sample at 210 nm.
11.4 Audit Sample Analysis. Same as Method 7, section 11.4, except
that a set of audit samples must be analyzed with each set of compliance
samples or once per analysis day, or once per week when averaging
continuous samples.
12.0 Data Analysis and Calculations
Same as Method 7, section 12.0, except replace section 12.3 with the
following:
12.1 Total [micro]g NO2 Per Sample.
[GRAPHIC] [TIFF OMITTED] TR17OC00.211
Where:
5 = 100/20, the aliquot factor.
[[Page 278]]
Note: If other than a 20-ml aliquot is used for analysis, the factor
5 must be replaced by a corresponding factor.
13.0 Method Performance
13.1 Range. The analytical range of the method as outlined has been
determined to be 57 to 1500 milligrams NOX (as
NO2) per dry standard cubic meter, or 30 to 786 parts per
million by volume (ppmv) NOX.
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
1. National Institute for Occupational Safety and Health.
Recommendations for Occupational Exposure to Nitric Acid. In:
Occupational Safety and Health Reporter. Washington, D.C. Bureau of
National Affairs, Inc. 1976. p. 149.
2. Rennie, P.J., A.M. Sumner, and F.B. Basketter. Determination of
Nitrate in Raw, Potable, and Waste Waters by Ultraviolet
Spectrophotometry. Analyst. 104:837. September 1979.
17.0 Tables, Diagrams, Flowcharts, and Validation Data [Reserved]
Method 7C--Determination of Nitrogen Oxide Emissions From Stationary
Sources (Alkaline Permanganate/Colorimetric Method)
Note: This method does not include all of the specifications (e.g.,
equipment and supplies) and procedures (e.g., sampling and analytical)
essential to its performance. Some material is incorporated by reference
from other methods in this part. Therefore, to obtain reliable results,
persons using this method should have a thorough knowledge of at least
the following additional test methods: Method 1, Method 3, Method 6 and
Method 7.
1.0 Scope and Application
1.1 Analytes.
------------------------------------------------------------------------
Analyte CAS no. Sensitivity
------------------------------------------------------------------------
Nitrogen oxides (NOX), as NO2,
including:
Nitric oxide (NO)............. 10102-43-9 ....................
Nitrogen dioxide (NO2)........ 10102-44-07 ppmv
------------------------------------------------------------------------
1.2 Applicability. This method applies to the measurement of
NOX emissions from fossil-fuel fired steam generators,
electric utility plants, nitric acid plants, or other sources as
specified in the regulations.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
An integrated gas sample is extracted from the stack and passed
through impingers containing an alkaline potassium permanganate
solution; NOX (NO + NO2) emissions are oxidized to
NO2 and NO3. Then NO3-is
reduced to NO2-with cadmium, and the
NO2-is analyzed colorimetrically.
3.0 Definitions [Reserved]
4.0 Interferences
Possible interferents are sulfur dioxides (SO2) and
ammonia (NH3).
4.1 High concentrations of SO2 could interfere because
SO2 consumes MnO4 (as does NOX) and,
therefore, could reduce the NOX collection efficiency.
However, when sampling emissions from a coal-fired electric utility
plant burning 2.1 percent sulfur coal with no control of SO2
emissions, collection efficiency was not reduced. In fact, calculations
show that sampling 3000 ppm SO2 will reduce the
MnO4 concentration by only 5 percent if all the
SO2 is consumed in the first impinger.
4.2 Ammonia (NH3) is slowly oxidized to
NO3- by the absorbing solution. At 100 ppm
NH3 in the gas stream, an interference of 6 ppm
NOX (11 mg NO2/m\3\) was observed when the sample
was analyzed 10 days after collection. Therefore, the method may not be
applicable to plants using NH3 injection to control
NOX emissions unless means are taken to correct the results.
An equation has been developed to allow quantification of the
interference and is discussed in Reference 5 of section 16.0.
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and to determine the applicability of regulatory limitations
prior to performing this test method.
5.2 Corrosive Reagents. The following reagents are hazardous.
Personal protective equipment and safe procedures are useful in
preventing chemical splashes. If contact occurs, immediately flush with
copious amounts of water for at least 15 minutes. Remove clothing under
shower and decontaminate. Treat residual chemical burns as thermal
burns.
[[Page 279]]
5.2.1 Hydrochloric Acid (HCl). Highly toxic and corrosive. Causes
severe damage to skin. Vapors are highly irritating to eyes, skin, nose,
and lungs, causing severe damage. May cause bronchitis, pneumonia, or
edema of lungs. Exposure to vapor concentrations of 0.13 to 0.2 percent
can be lethal in minutes. Will react with metals, producing hydrogen.
5.2.2 Oxalic Acid (COOH)2. Poisonous. Irritating to eyes,
skin, nose, and throat.
5.2.3 Sodium Hydroxide (NaOH). Causes severe damage to eye tissues
and to skin. Inhalation causes irritation to nose, throat, and lungs.
Reacts exothermically with small amounts of water.
5.2.4 Potassium Permanganate (KMnO4). Caustic, strong
oxidizer. Avoid bodily contact with.
6.0 Equipment and Supplies
6.1 Sample Collection and Sample Recovery. A schematic of the Method
7C sampling train is shown in Figure 7C-1, and component parts are
discussed below. Alternative apparatus and procedures are allowed
provided acceptable accuracy and precision can be demonstrated to the
satisfaction of the Administrator.
6.1.1 Probe. Borosilicate glass tubing, sufficiently heated to
prevent water condensation and equipped with an in-stack or heated out-
of-stack filter to remove particulate matter (a plug of glass wool is
satisfactory for this purpose). Stainless steel or Teflon tubing may
also be used for the probe.
6.1.2 Impingers. Three restricted-orifice glass impingers, having
the specifications given in Figure 7C-2, are required for each sampling
train. The impingers must be connected in series with leak-free glass
connectors. Stopcock grease may be used, if necessary, to prevent
leakage. (The impingers can be fabricated by a glass blower if not
available commercially.)
6.1.3 Glass Wool, Stopcock Grease, Drying Tube, Valve, Pump,
Barometer, and Vacuum Gauge and Rotameter. Same as in Method 6, sections
6.1.1.3, 6.1.1.4, 6.1.1.6, 6.1.1.7, 6.1.1.8, 6.1.2, and 6.1.3,
respectively.
6.1.4 Rate Meter. Rotameter, or equivalent, accurate to within 2
percent at the selected flow rate of between 400 and 500 ml/min (0.014
to 0.018 cfm). For rotameters, a range of 0 to 1 liter/min (0 to 0.035
cfm) is recommended.
6.1.5 Volume Meter. Dry gas meter (DGM) capable of measuring the
sample volume under the sampling conditions of 400 to 500 ml/min (0.014
to 0.018 cfm) for 60 minutes within an accuracy of 2 percent.
6.1.6 Filter. To remove NOX from ambient air, prepared by
adding 20 g of 5-angstrom molecular sieve to a cylindrical tube (e.g., a
polyethylene drying tube).
6.1.7 Polyethylene Bottles. 1-liter, for sample recovery.
6.1.8 Funnel and Stirring Rods. For sample recovery.
6.2 Sample Preparation and Analysis.
6.2.1 Hot Plate. Stirring type with 50- by 10-mm Teflon-coated
stirring bars.
6.2.2 Beakers. 400-, 600-, and 1000-ml capacities.
6.2.3 Filtering Flask. 500-ml capacity with side arm.
6.2.4 Buchner Funnel. 75-mm ID, with spout equipped with a 13-mm ID
by 90-mm long piece of Teflon tubing to minimize possibility of
aspirating sample solution during filtration.
6.2.5 Filter Paper. Whatman GF/C, 7.0-cm diameter.
6.2.6 Stirring Rods.
6.2.7 Volumetric Flasks. 100-, 200- or 250-, 500-, and 1000-ml
capacity.
6.2.8 Watch Glasses. To cover 600- and 1000-ml beakers.
6.2.9 Graduated Cylinders. 50- and 250-ml capacities.
6.2.10 Pipettes. Class A.
6.2.11 pH Meter. To measure pH from 0.5 to 12.0.
6.2.12 Burette. 50-ml with a micrometer type stopcock. (The stopcock
is Catalog No. 8225-t-05, Ace Glass, Inc., Post Office Box 996,
Louisville, Kentucky 50201.) Place a glass wool plug in bottom of
burette. Cut off burette at a height of 43 cm (17 in.) from the top of
plug, and have a blower attach a glass funnel to top of burette such
that the diameter of the burette remains essentially unchanged. Other
means of attaching the funnel are acceptable.
6.2.13 Glass Funnel. 75-mm ID at the top.
6.2.14 Spectrophotometer. Capable of measuring absorbance at 540 nm;
1-cm cells are adequate.
6.2.15 Metal Thermometers. Bimetallic thermometers, range 0 to 150
[deg]C (32 to 300 [deg]F).
6.2.16 Culture Tubes. 20-by 150-mm, Kimax No. 45048.
6.2.17 Parafilm ``M.'' Obtained from American Can Company,
Greenwich, Connecticut 06830.
6.2.18 CO2 Measurement Equipment. Same as in Method 3,
section 6.0.
7.0 Reagents and Standards
Unless otherwise indicated, it is intended that all reagents conform
to the specifications established by the Committee on Analytical
Reagents of the American Chemical Society, where such specifications are
available; otherwise, use the best available grade.
7.1 Sample Collection.
7.1.1 Water. Deionized distilled to conform to ASTM Specification D
1193-77 or 91 Type 3 (incorporated by reference--see Sec. 60.17).
7.1.2 Potassium Permanganate, 4.0 Percent (w/w), Sodium Hydroxide,
2.0 Percent (w/w) solution (KMnO4/NaOH solution). Dissolve
40.0 g of KMnO4 and 20.0 g of NaOH in 940 ml of water.
7.2 Sample Preparation and Analysis.
7.2.1 Water. Same as in section 7.1.1.
[[Page 280]]
7.2.2 Oxalic Acid Solution. Dissolve 48 g of oxalic acid
[(COOH)2[middot]2H2O] in water, and dilute to 500
ml. Do not heat the solution.
7.2.3 Sodium Hydroxide, 0.5 N. Dissolve 20 g of NaOH in water, and
dilute to 1 liter.
7.2.4 Sodium Hydroxide, 10 N. Dissolve 40 g of NaOH in water, and
dilute to 100 ml.
7.2.5 Ethylenediamine Tetraacetic Acid (EDTA) Solution, 6.5 percent
(w/v). Dissolve 6.5 g of EDTA (disodium salt) in water, and dilute to
100 ml. Dissolution is best accomplished by using a magnetic stirrer.
7.2.6 Column Rinse Solution. Add 20 ml of 6.5 percent EDTA solution
to 960 ml of water, and adjust the pH to between 11.7 and 12.0 with 0.5
N NaOH.
7.2.7 Hydrochloric Acid (HCl), 2 N. Add 86 ml of concentrated HCl to
a 500 ml-volumetric flask containing water, dilute to volume, and mix
well. Store in a glass-stoppered bottle.
7.2.8 Sulfanilamide Solution. Add 20 g of sulfanilamide (melting
point 165 to 167 [deg]C (329 to 333 [deg]F)) to 700 ml of water. Add,
with mixing, 50 ml concentrated phosphoric acid (85 percent), and dilute
to 1000 ml. This solution is stable for at least 1 month, if
refrigerated.
7.2.9 N-(1-Naphthyl)-Ethylenediamine Dihydrochloride (NEDA)
Solution. Dissolve 0.5 g of NEDA in 500 ml of water. An aqueous solution
should have one absorption peak at 320 nm over the range of 260 to 400
nm. NEDA that shows more than one absorption peak over this range is
impure and should not be used. This solution is stable for at least 1
month if protected from light and refrigerated.
7.2.10 Cadmium. Obtained from Matheson Coleman and Bell, 2909
Highland Avenue, Norwood, Ohio 45212, as EM Laboratories Catalog No.
2001. Prepare by rinsing in 2 N HCl for 5 minutes until the color is
silver-grey. Then rinse the cadmium with water until the rinsings are
neutral when tested with pH paper. CAUTION: H2 is liberated
during preparation. Prepare in an exhaust hood away from any flame or
combustion source.
7.2.11 Sodium Sulfite (NaNO2) Standard Solution, Nominal
Concentration, 1000 [micro]g NO2-/ml. Desiccate
NaNO2 overnight. Accurately weigh 1.4 to 1.6 g of NaNO2
(assay of 97 percent NaNO2 or greater), dissolve in water,
and dilute to 1 liter. Calculate the exact NO2-concentration
using Equation 7C-1 in section 12.2. This solution is stable for at
least 6 months under laboratory conditions.
7.2.12 Potassium Nitrate (KNO3) Standard Solution. Dry
KNO3 at 110 [deg]C (230 [deg]F) for 2 hours, and cool in a
desiccator. Accurately weigh 9 to 10 g of KNO3 to within 0.1
mg, dissolve in water, and dilute to 1 liter. Calculate the exact
NO3- concentration using Equation 7C-2 in section
12.3. This solution is stable for 2 months without preservative under
laboratory conditions.
7.2.13 Spiking Solution. Pipette 7 ml of the KNO3
standard into a 100-ml volumetric flask, and dilute to volume.
7.2.14 Blank Solution. Dissolve 2.4 g of KMnO4 and 1.2 g
of NaOH in 96 ml of water. Alternatively, dilute 60 ml of
KMnO4/NaOH solution to 100 ml.
8.0 Sample Collection, Preservation, Storage, and Transport
8.1 Preparation of Sampling Train. Add 200 ml of KMnO4/
NaOH solution (Section 7.1.2) to each of three impingers, and assemble
the train as shown in Figure 7C-1. Adjust the probe heater to a
temperature sufficient to prevent water condensation.
8.2 Leak-Checks. Same as in Method 6, section 8.2.
8.3 Sample Collection.
8.3.1 Record the initial DGM reading and barometric pressure.
Determine the sampling point or points according to the appropriate
regulations (e.g., Sec. 60.46(b)(5) of 40 CFR Part 60). Position the
tip of the probe at the sampling point, connect the probe to the first
impinger, and start the pump. Adjust the sample flow to a value between
400 and 500 ml/min (0.014 and 0.018 cfm). CAUTION: DO NOT EXCEED THESE
FLOW RATES. Once adjusted, maintain a constant flow rate during the
entire sampling run. Sample for 60 minutes. For relative accuracy (RA)
testing of continuous emission monitors, the minimum sampling time is 1
hour, sampling 20 minutes at each traverse point.
Note: When the SO2 concentration is greater than 1200
ppm, the sampling time may have to be reduced to 30 minutes to eliminate
plugging of the impinger orifice with MnO2. For RA tests with
SO2 greater than 1200 ppm, sample for 30 minutes (10 minutes
at each point).
8.3.2 Record the DGM temperature, and check the flow rate at least
every 5 minutes. At the conclusion of each run, turn off the pump,
remove the probe from the stack, and record the final readings. Divide
the sample volume by the sampling time to determine the average flow
rate. Conduct the mandatory post-test leak-check. If a leak is found,
void the test run, or use procedures acceptable to the Administrator to
adjust the sample volume for the leakage.
8.4 CO2 Measurement. During sampling, measure the
CO2 content of the stack gas near the sampling point using
Method 3. The single-point grab sampling procedure is adequate, provided
the measurements are made at least three times (near the start, midway,
and before the end of a run), and the average CO2
concentration is computed. The Orsat or Fyrite analyzer may be used for
this analysis.
8.5 Sample Recovery. Disconnect the impingers. Pour the contents of
the impingers into a 1-liter polyethylene bottle
[[Page 281]]
using a funnel and a stirring rod (or other means) to prevent spillage.
Complete the quantitative transfer by rinsing the impingers and
connecting tubes with water until the rinsings are clear to light pink,
and add the rinsings to the bottle. Mix the sample, and mark the
solution level. Seal and identify the sample container.
9.0 Quality Control
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
8.2, 10.1-10.3................ Sampling Ensure accurate
equipment leak- measurement of
check and sample volume.
calibration.
10.4.......................... Spectrophotometer Ensure linearity of
calibration. spectrophotometer
response to
standards
11.3.......................... Spiked sample Ensure reduction
analysis.. efficiency of
column.
------------------------------------------------------------------------
10.0 Calibration and Standardizations
10.1 Volume Metering System. Same as Method 6, section 10.1. For
detailed instructions on carrying out these calibrations, it is
suggested that section 3.5.2 of Reference 4 of section 16.0 be
consulted.
10.2 Temperature Sensors and Barometer. Same as in Method 6,
sections 10.2 and 10.4, respectively.
10.3 Check of Rate Meter Calibration Accuracy (Optional). Disconnect
the probe from the first impinger, and connect the filter. Start the
pump, and adjust the rate meter to read between 400 and 500 ml/min
(0.014 and 0.018 cfm). After the flow rate has stabilized, start
measuring the volume sampled, as recorded by the dry gas meter and the
sampling time. Collect enough volume to measure accurately the flow
rate. Then calculate the flow rate. This average flow rate must be less
than 500 ml/min (0.018 cfm) for the sample to be valid; therefore, it is
recommended that the flow rate be checked as above prior to each test.
10.4 Spectrophotometer.
10.4.1 Dilute 5.0 ml of the NaNO2 standard solution to
200 ml with water. This solution nominally contains 25 [micro]g
NO2-/ml. Use this solution to prepare calibration
standards to cover the range of 0.25 to 3.00 [micro]g
NO2-/ml. Prepare a minimum of three standards each
for the linear and slightly nonlinear (described below) range of the
curve. Use pipettes for all additions.
10.4.2 Measure the absorbance of the standards and a water blank as
instructed in section 11.5. Plot the net absorbance vs. [micro]g
NO2-/ml. Draw a smooth curve through the points.
The curve should be linear up to an absorbance of approximately 1.2 with
a slope of approximately 0.53 absorbance units/[micro]g
NO2-/ml. The curve should pass through the origin.
The curve is slightly nonlinear from an absorbance of 1.2 to 1.6.
11.0 Analytical Procedures
11.1 Sample Stability. Collected samples are stable for at least
four weeks; thus, analysis must occur within 4 weeks of collection.
11.2 Sample Preparation.
11.2.1 Prepare a cadmium reduction column as follows: Fill the
burette with water. Add freshly prepared cadmium slowly, with tapping,
until no further settling occurs. The height of the cadmium column
should be 39 cm (15 in). When not in use, store the column under rinse
solution.
Note: The column should not contain any bands of cadmium fines. This
may occur if regenerated cadmium is used and will greatly reduce the
column lifetime.
11.2.2 Note the level of liquid in the sample container, and
determine whether any sample was lost during shipment. If a noticeable
amount of leakage has occurred, the volume lost can be determined from
the difference between initial and final solution levels, and this value
can then be used to correct the analytical result. Quantitatively
transfer the contents to a 1-liter volumetric flask, and dilute to
volume.
11.2.3 Take a 100-ml aliquot of the sample and blank (unexposed
KMnO4/NaOH) solutions, and transfer to 400-ml beakers
containing magnetic stirring bars. Using a pH meter, add concentrated
H2SO4 with stirring until a pH of 0.7 is obtained.
Allow the solutions to stand for 15 minutes. Cover the beakers with
watch glasses, and bring the temperature of the solutions to 50 [deg]C
(122 [deg]F). Keep the temperature below 60 [deg]C (140 [deg]F).
Dissolve 4.8 g of oxalic acid in a minimum volume of water,
approximately 50 ml, at room temperature. Do not heat the solution. Add
this solution slowly, in increments, until the KMnO4 solution
becomes colorless. If the color is not completely removed, prepare some
more of the above oxalic acid solution, and add until a colorless
solution is obtained. Add an excess of oxalic acid by dissolving 1.6 g
of oxalic acid in 50 ml of water, and add 6 ml of this solution to the
colorless solution. If suspended matter is present, add concentrated
H2SO4 until a clear solution is obtained.
11.2.4 Allow the samples to cool to near room temperature, being
sure that the samples are still clear. Adjust the pH to between 11.7 and
12.0 with 10 N NaOH. Quantitatively transfer the mixture to a Buchner
funnel containing GF/C filter paper, and filter the
[[Page 282]]
precipitate. Filter the mixture into a 500-ml filtering flask. Wash the
solid material four times with water. When filtration is complete, wash
the Teflon tubing, quantitatively transfer the filtrate to a 500-ml
volumetric flask, and dilute to volume. The samples are now ready for
cadmium reduction. Pipette a 50-ml aliquot of the sample into a 150-ml
beaker, and add a magnetic stirring bar. Pipette in 1.0 ml of 6.5
percent EDTA solution, and mix.
11.3 Determine the correct stopcock setting to establish a flow rate
of 7 to 9 ml/min of column rinse solution through the cadmium reduction
column. Use a 50-ml graduated cylinder to collect and measure the
solution volume. After the last of the rinse solution has passed from
the funnel into the burette, but before air entrapment can occur, start
adding the sample, and collect it in a 250-ml graduated cylinder.
Complete the quantitative transfer of the sample to the column as the
sample passes through the column. After the last of the sample has
passed from the funnel into the burette, start adding 60 ml of column
rinse solution, and collect the rinse solution until the solution just
disappears from the funnel. Quantitatively transfer the sample to a 200-
ml volumetric flask (a 250-ml flask may be required), and dilute to
volume. The samples are now ready for NO2-analysis.
Note: Two spiked samples should be run with every group of samples
passed through the column. To do this, prepare two additional 50-ml
aliquots of the sample suspected to have the highest NO2-
concentration, and add 1 ml of the spiking solution to these aliquots.
If the spike recovery or column efficiency (see section 12.2) is below
95 percent, prepare a new column, and repeat the cadmium reduction.
11.5 Sample Analysis. Pipette 10 ml of sample into a culture tube.
Pipette in 10 ml of sulfanilamide solution and 1.4 ml of NEDA solution.
Cover the culture tube with parafilm, and mix the solution. Prepare a
blank in the same manner using the sample from treatment of the
unexposed KMnO4/NaOH solution. Also, prepare a calibration
standard to check the slope of the calibration curve. After a 10-minute
color development interval, measure the absorbance at 540 nm against
water. Read [micro]g NO2-/ml from the calibration
curve. If the absorbance is greater than that of the highest calibration
standard, use less than 10 ml of sample, and repeat the analysis.
Determine the NO2-concentration using the
calibration curve obtained in section 10.4.
Note: Some test tubes give a high blank NO2-
value but culture tubes do not.
11.6 Audit Sample Analysis. Same as in Method 7, section 11.4.
12.0 Data Analysis and Calculations
Carry out calculations, retaining at least one extra significant
figure beyond that of the acquired data. Round off figures after final
calculation.
12.1 Nomenclature.
B = Analysis of blank, [micro]g NO2-/ml.
C = Concentration of NOX as NO2, dry basis, mg/
dsm\3\.
E = Column efficiency, dimensionless
K2 = 10-3 mg/[micro]g.
m = Mass of NOX, as NO2, in sample, [micro]g.
Pbar = Barometric pressure, mm Hg (in. Hg).
Pstd = Standard absolute pressure, 760 mm Hg (29.92 in. Hg).
s = Concentration of spiking solution, [micro]g NO3/ml.
S = Analysis of sample, [micro]g NO2-/ml.
Tm = Average dry gas meter absolute temperature, [deg]K.
Tstd = Standard absolute temperature, 293 [deg]K (528
[deg]R).
Vm(std) = Dry gas volume measured by the dry gas meter,
corrected to standard conditions, dscm (dscf).
Vm = Dry gas volume as measured by the dry gas meter, scm
(scf).
x = Analysis of spiked sample, [micro]g NO2-/ml.
X = Correction factor for CO2 collection = 100/(100 -
%CO2(V/V)).
y = Analysis of unspiked sample, [micro]g NO2-/ml.
Y = Dry gas meter calibration factor.
1.0 ppm NO = 1.247 mg NO/m\3\ at STP.
1.0 ppm NO2 = 1.912 mg NO2/m\3\ at STP.
1 ft\3\ = 2.832 x 10-2 m\3\.
12.2 NO2 Concentration. Calculate the NO2
concentration of the solution (see section 7.2.11) using the following
equation:
[GRAPHIC] [TIFF OMITTED] TR17OC00.212
12.3 NO3 Concentration. Calculate the NO3
concentration of the KNO3 solution (see section 7.2.12) using
the following equation:
[[Page 283]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.213
12.4 Sample Volume, Dry Basis, Corrected to Standard Conditions.
[GRAPHIC] [TIFF OMITTED] TR17OC00.214
Where:
K1 = 0.3855 [deg]K/mm Hg for metric units.
K1 = 17.65 [deg]R/in. Hg for English units.
12.5 Efficiency of Cadmium Reduction Column. Calculate this value as
follows:
[GRAPHIC] [TIFF OMITTED] TR17OC00.215
Where:
200 = Final volume of sample and blank after passing through the column,
ml.
1.0 = Volume of spiking solution added, ml.
46.01=[micro]g NO2-/[micro]mole.
62.01=[micro]g NO3-/[micro]mole.
12.6 Total [micro]g NO2.
[GRAPHIC] [TIFF OMITTED] TR17OC00.216
Where:
500 = Total volume of prepared sample, ml.
50 = Aliquot of prepared sample processed through cadmium column, ml.
100 = Aliquot of KMnO4/NaOH solution, ml.
1000 = Total volume of KMnO4/NaOH solution, ml.
12.7 Sample Concentration.
[GRAPHIC] [TIFF OMITTED] TR17OC00.217
13.0 Method Performance
13.1 Precision. The intra-laboratory relative standard deviation for
a single measurement is 2.8 and 2.9 percent at 201 and 268 ppm
NOX, respectively.
13.2 Bias. The method does not exhibit any bias relative to Method
7.
13.3 Range. The lower detectable limit is 13 mg NOX/m\3\,
as NO2 (7 ppm NOX) when sampling at 500 ml/min for
1 hour. No upper limit has been established; however, when using the
recommended sampling conditions, the method has been found to collect
NOX emissions quantitatively up to 1782 mg NOX/
m\3\, as NO2 (932 ppm NOX).
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
1. Margeson, J.H., W.J. Mitchell, J.C. Suggs, and M.R. Midgett.
Integrated Sampling and Analysis Methods for Determining NOX
Emissions at Electric Utility Plants. U.S. Environmental Protection
Agency, Research Triangle Park, NC. Journal of the Air Pollution Control
Association. 32:1210-1215. 1982.
2. Memorandum and attachment from J.H. Margeson, Source Branch,
Quality Assurance Division, Environmental Monitoring Systems Laboratory,
to The Record, EPA. March 30, 1983. NH3 Interference in
Methods 7C and 7D.
3. Margeson, J.H., J.C. Suggs, and M.R. Midgett. Reduction of
Nitrate to Nitrite with Cadmium. Anal. Chem. 52:1955-57. 1980.
4. Quality Assurance Handbook for Air Pollution Measurement Systems.
Volume III--Stationary Source Specific Methods. U.S.
[[Page 284]]
Environmental Protection Agency. Research Triangle Park, NC. Publication
No. EPA-600/4-77-027b. August 1977.
5. Margeson, J.H., et al. An Integrated Method for Determining
NOX Emissions at Nitric Acid Plants. Analytical Chemistry. 47
(11):1801. 1975.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
[GRAPHIC] [TIFF OMITTED] TR17OC00.218
[[Page 285]]
[GRAPHIC] [TIFF OMITTED] TR17OC00.219
Method 7D--Determination of Nitrogen Oxide Emissions From Stationary
Sources (Alkaline-Permanganate/Ion Chromatographic Method)
Note: This method is not inclusive with respect to specifications
(e.g., equipment and supplies) and procedures (e.g., sampling and
analytical) essential to its performance. Some material is incorporated
by reference from other methods in this part. Therefore, to obtain
reliable results, persons using this method should have a thorough
knowledge of at least the following additional test methods: Method 1,
Method 3, Method 6, Method 7, and Method 7C.
1.0 Scope and Application
1.1 Analytes.
[[Page 286]]
------------------------------------------------------------------------
Analyte CAS No. Sensitivity
------------------------------------------------------------------------
Nitrogen oxides (NOX), as NO2,
including:
Nitric oxide (NO)............. 10102-43-9
Nitrogen dioxide (NO2)........ 10102-44-0 7 ppmv
------------------------------------------------------------------------
1.2 Applicability. This method applies to the measurement of
NOX emissions from fossil-fuel fired steam generators,
electric utility plants, nitric acid plants, or other sources as
specified in the regulations.
1.3 Data Quality Objectives. Adherence to the requirements of this
method will enhance the quality of the data obtained from air pollutant
sampling methods.
2.0 Summary of Method
An integrated gas sample is extracted from the stack and passed
through impingers containing an alkaline-potassium permanganate
solution; NOX (NO + NO2) emissions are oxidized to
NO3-. Then NO3- is analyzed
by ion chromatography.
3.0 Definitions [Reserved]
4.0 Interferences
Same as in Method 7C, section 4.0.
5.0 Safety
5.1 Disclaimer. This method may involve hazardous materials,
operations, and equipment. This test method may not address all of the
safety problems associated with its use. It is the responsibility of the
user of this test method to establish appropriate safety and health
practices and to determine the applicability of regulatory limitations
prior to performing this test method.
5.2 Corrosive reagents. The following reagents are hazardous.
Personal protective equipment and safe procedures are useful in
preventing chemical splashes. If contact occurs, immediately flush with
copious amounts of water for at least 15 minutes. Remove clothing under
shower and decontaminate. Treat residual chemical burns as thermal
burns.
5.2.1 Hydrogen Peroxide (H2O2). Irritating to
eyes, skin, nose, and lungs. 30% H2O2 is a strong
oxidizing agent; avoid contact with skin, eyes, and combustible
material. Wear gloves when handling.
5.2.2 Sodium Hydroxide (NaOH). Causes severe damage to eye tissues
and to skin. Inhalation causes irritation to nose, throat, and lungs.
Reacts exothermically with limited amounts of water.
5.2.3 Potassium Permanganate (KMnO4). Caustic, strong
oxidizer. Avoid bodily contact with.
6.0 Equipment and Supplies
6.1 Sample Collection and Sample Recovery. Same as Method 7C,
section 6.1. A schematic of the sampling train used in performing this
method is shown in Figure 7C-1 of Method 7C.
6.2 Sample Preparation and Analysis.
6.2.1 Magnetic Stirrer. With 25- by 10-mm Teflon-coated stirring
bars.
6.2.2 Filtering Flask. 500-ml capacity with sidearm.
6.2.3 Buchner Funnel. 75-mm ID, with spout equipped with a 13-mm ID
by 90-mm long piece of Teflon tubing to minimize possibility of
aspirating sample solution during filtration.
6.2.4 Filter Paper. Whatman GF/C, 7.0-cm diameter.
6.2.5 Stirring Rods.
6.2.6 Volumetric Flask. 250-ml.
6.2.7 Pipettes. Class A.
6.2.8 Erlenmeyer Flasks. 250-ml.
6.2.9 Ion Chromatograph. Equipped with an anion separator column to
separate NO3-, H3\ + \ suppressor, and
necessary auxiliary equipment. Nonsuppressed and other forms of ion
chromatography may also be used provided that adequate resolution of
NO3- is obtained. The system must also be able to
resolve and detect NO2-.
7.0 Reagents and Standards
Note: Unless otherwise indicated, it is intended that all reagents
conform to the specifications established by the Committee on Analytical
Reagents of the American Chemical Society, where such specifications are
available; otherwise, use the best available grade.
7.1 Sample Collection.
7.1.1 Water. Deionized distilled to conform to ASTM specification D
1193-77 or 91 Type 3 (incorporated by reference--see Sec. 60.17).
7.1.2 Potassium Permanganate, 4.0 Percent (w/w), Sodium Hydroxide,
2.0 Percent (w/w). Dissolve 40.0 g of KMnO4 and 20.0 g of
NaOH in 940 ml of water.
7.2 Sample Preparation and Analysis.
7.2.1 Water. Same as in section 7.1.1.
7.2.2 Hydrogen Peroxide (H2O2), 5 Percent.
Dilute 30 percent H2O2 1:5 (v/v) with water.
7.2.3 Blank Solution. Dissolve 2.4 g of KMnO4 and 1.2 g
of NaOH in 96 ml of water. Alternatively, dilute 60 ml of
KMnO4/NaOH solution to 100 ml.
7.2.4 KNO3 Standard Solution. Dry KNO3 at 110
[deg]C for 2 hours, and cool in a desiccator. Accurately weigh 9 to 10 g
of KNO3 to within 0.1 mg, dissolve in water, and dilute to 1
liter. Calculate the exact NO3- concentration
using Equation 7D-1 in section 12.2. This
[[Page 287]]
solution is stable for 2 months without preservative under laboratory
conditions.
7.2.5 Eluent, 0.003 M NaHCO3/0.0024 M
Na2CO3. Dissolve 1.008 g NaHCO3 and
1.018 g Na2CO3 in water, and dilute to 4 liters.
Other eluents capable of resolving nitrate ion from sulfate and other
species present may be used.
8.0 Sample Collection, Preservation, Transport, and Storage.
8.1 Sampling. Same as in Method 7C, section 8.1.
8.2 Sample Recovery. Same as in Method 7C, section 8.2.
8.3 Sample Preparation for Analysis.
Note: Samples must be analyzed within 28 days of collection.
8.3.1 Note the level of liquid in the sample container, and
determine whether any sample was lost during shipment. If a noticeable
amount of leakage has occurred, the volume lost can be determined from
the difference between initial and final solution levels, and this value
can then be used to correct the analytical result. Quantitatively
transfer the contents to a 1-liter volumetric flask, and dilute to
volume.
8.3.2 Sample preparation can be started 36 hours after collection.
This time is necessary to ensure that all NO2- is
converted to NO3- in the collection solution. Take
a 50-ml aliquot of the sample and blank, and transfer to 250-ml
Erlenmeyer flasks. Add a magnetic stirring bar. Adjust the stirring rate
to as fast a rate as possible without loss of solution. Add 5 percent
H2O2 in increments of approximately 5 ml using a
5-ml pipette. When the KMnO4 color appears to have been
removed, allow the precipitate to settle, and examine the supernatant
liquid. If the liquid is clear, the H2O2 addition
is complete. If the KMnO4 color persists, add more
H2O2, with stirring, until the supernatant liquid
is clear.
Note: The faster the stirring rate, the less volume of
H2O2 that will be required to remove the
KMnO4.) Quantitatively transfer the mixture to a Buchner
funnel containing GF/C filter paper, and filter the precipitate. The
spout of the Buchner funnel should be equipped with a 13-mm ID by 90-mm
long piece of Teflon tubing. This modification minimizes the possibility
of aspirating sample solution during filtration. Filter the mixture into
a 500-ml filtering flask. Wash the solid material four times with water.
When filtration is complete, wash the Teflon tubing, quantitatively
transfer the filtrate to a 250-ml volumetric flask, and dilute to
volume. The sample and blank are now ready for
NO3-analysis.
9.0 Quality Control
------------------------------------------------------------------------
Quality control
Section measure Effect
------------------------------------------------------------------------
8.2, 10.1-10.3................ Sampling Ensure accurate
equipment leak- measurement of
check and sample volume.
calibration.
10.4.......................... Spectrophotometer Ensure linearity of
calibration. spectrophotometer
response to
standards.
11.3.......................... Spiked sample Ensure reduction
analysis. efficiency of
column.
------------------------------------------------------------------------
10.0 Calibration and Standardizations
10.1 Dry Gas Meter (DGM) System.
10.1.1 Initial Calibration. Same as in Method 6, section 10.1.1. For
detailed instructions on carrying out this calibration, it is suggested
that section 3.5.2 of Citation 4 in section 16.0 of Method 7C be
consulted.
10.1.2 Post-Test Calibration Check. Same as in Method 6, section
10.1.2.
10.2 Thermometers for DGM and Barometer. Same as in Method 6,
sections 10.2 and 10.4, respectively.
10.3 Ion Chromatograph.
10.3.1 Dilute a given volume (1.0 ml or greater) of the
KNO3 standard solution to a convenient volume with water, and
use this solution to prepare calibration standards. Prepare at least
four standards to cover the range of the samples being analyzed. Use
pipettes for all additions. Run standards as instructed in section 11.2.
Determine peak height or area, and plot the individual values versus
concentration in [micro]g NO3-/ml.
10.3.2 Do not force the curve through zero. Draw a smooth curve
through the points. The curve should be linear. With the linear curve,
use linear regression to determine the calibration equation.
11.0 Analytical Procedures
11.1 The following chromatographic conditions are recommended: 0.003
M NaHCO3/0.0024 Na2CO3 eluent solution
(Section 7.2.5), full scale range, 3 [micro]MHO; sample loop, 0.5 ml;
flow rate, 2.5 ml/min. These conditions should give a
NO3- retention time of approximately 15 minutes
(Figure 7D-1).
11.2 Establish a stable baseline. Inject a sample of water, and
determine whether any NO3- appears in the
chromatogram. If NO3- is present, repeat the water
load/injection procedure approximately five times; then re-inject a
water sample and observe the chromatogram. When no
NO3- is present, the instrument is ready for use.
Inject calibration standards. Then inject samples and a blank. Repeat
the injection of the calibration
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standards (to compensate for any drift in response of the instrument).
Measure the NO3- peak height or peak area, and
determine the sample concentration from the calibration curve.
12.0 Data Analysis and Calculations
Carry out calculations, retaining at least one extra significant
figure beyond that of the acquired data. Round off figures after final
calculation.
12.1 Nomenclature. Same as in Method 7C, section 12.1.
12.2 NO3- concentration. Calculate the
NO3- concentration in the KNO3 standard
solution (see section 7.2.4) using the following equation:
[GRAPHIC] [TIFF OMITTED] TR17OC00.220
12.3 Sample Volume, Dry Basis, Corrected to Standard Conditions.
Same as in Method 7C, section 12.4.
12.4 Total [micro]g NO2 Per Sample.
[GRAPHIC] [TIFF OMITTED] TR17OC00.221
Where:
250 = Volume of prepared sample, ml.
1000 = Total volume of KMnO4 solution, ml.
50 = Aliquot of KMnO4/NaOH solution, ml.
46.01 = Molecular weight of NO3-.
62.01 = Molecular weight of NO3-.
12.5 Sample Concentration. Same as in Method 7C, section 12.7.
13.0 Method Performance
13.1 Precision. The intra-laboratory relative standard deviation for
a single measurement is approximately 6 percent at 200 to 270 ppm
NOX.
13.2 Bias. The method does not exhibit any bias relative to Method
7.
13.3 Range. The lower detectable limit is similar to that of Method
7C. No upper limit has been established; however, when using the
recommended sampling conditions, the method has been found to collect
NOX emissions quantitatively up to 1782 mg NOX/
m\3\, as NO2 (932 ppm NOX).
14.0 Pollution Prevention [Reserved]
15.0 Waste Management [Reserved]
16.0 References
Same as Method 7C, section 16.0, References 1, 2, 4, and 5.
17.0 Tables, Diagrams, Flowcharts, and Validation Data
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[GRAPHIC] [TIFF OMITTED] TR17OC00.222
Method 7E--Determination of Nitrogen Oxides Emissions From Stationary
Sources (Instrumental Analyzer Procedure)
1.0 Scope and Application
What is Method 7E?
Method 7E is a procedure for measuring nitrogen oxides
(NOX) in stationary source emissions using a continuous
instrumental analyzer. Quality assurance and quality control
requirements are included to assure that you, the tester, collect data
of known quality. You must document your adherence to these specific
requirements for equipment, supplies, sample collection and analysis,
calculations, and data analysis. This method does not completely
describe all equipment, supplies, and sampling and analytical procedures
you will need but refers to other methods for some of the details.
Therefore, to obtain reliable results, you should also have a thorough
knowledge of these additional test methods which are found in appendix A
to this part:
(a) Method 1--Sample and Velocity Traverses for Stationary Sources.
(b) Method 4--Determination of Moisture Content in Stack Gases.
1.1 Analytes. What does this method determine? This method measures
the concentration of nitrogen oxides as NO2.
------------------------------------------------------------------------
Analyte CAS No. Sensitivity
------------------------------------------------------------------------
Nitric oxide (NO).............. 10102-43-9 Typically <2% of
Nitrogen dioxide (NO2)......... 10102-44-0 Calibration Span.
------------------------------------------------------------------------
1.2 Applicability. When is this method required? The use of Method
7E may be required by specific New Source Performance Standards, Clean
Air Marketing rules, State Implementation Plans, and permits where
measurement of NOX concentrations in stationary source
emissions is required, either to determine compliance with an applicable
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emissions standard or to conduct performance testing of a continuous
monitoring system (CEMS). Other regulations may also require the use of
Method 7E.
1.3 Data Quality Objectives (DQO). How good must my collected data
be? Method 7E is designed to provide high-quality data for determining
compliance with Federal and State emission standards and for relative
accuracy testing of CEMS. In these and other applications, the principal
objective is to ensure the accuracy of the data at the actual emission
levels encountered. To meet this objective, the use of EPA traceability
protocol calibration gases and measurement system performance tests are
required.
1.4 Data Quality Assessment for Low Emitters. Is performance relief
granted when testing low-emission units? Yes. For low-emitting sources,
there are alternative performance specifications for analyzer
calibration error, system bias, drift, and response time. Also, the
alternative dynamic spiking procedure in section 16 may provide
performance relief for certain low-emitting units.
2.0 Summary of Method
In this method, a sample of the effluent gas is continuously sampled
and conveyed to the analyzer for measuring the concentration of
NOX. You may measure NO and NO2 separately or
simultaneously together but, for the purposes of this method,
NOX is the sum of NO and NO2. You must meet the
performance requirements of this method to validate your data.
3.0 Definitions
3.1 Analyzer Calibration Error, for non-dilution systems, means the
difference between the manufacturer certified concentration of a
calibration gas and the measured concentration of the same gas when it
is introduced into the analyzer in direct calibration mode.
3.2 Calibration Curve means the relationship between an analyzer's
response to the injection of a series of calibration gases and the
actual concentrations of those gases.
3.3 Calibration Gas means the gas mixture containing NOX
at a known concentration and produced and certified in accordance with
``EPA Traceability Protocol for Assay and Certification of Gaseous
Calibration Standards,'' September 1997, as amended August 25, 1999,
EPA-600/R-97/121 or more recent updates. The tests for analyzer
calibration error, drift, and system bias require the use of calibration
gas prepared according to this protocol. If a zero gas is used for the
low-level gas, it must meet the requirements under the definition for
``zero air material'' in 40 CFR 72.2 in place of being prepared by the
traceability protocol.
3.3.1 Low-Level Gas means a calibration gas with a concentration
that is less than 20 percent of the calibration span and may be a zero
gas.
3.3.2 Mid-Level Gas means a calibration gas with a concentration
that is 40 to 60 percent of the calibration span.
3.3.3 High-Level Gas means a calibration gas with a concentration
that is equal to the calibration span.
3.4 Calibration Span means the upper limit of the analyzer's
calibration that is set by the choice of high-level calibration gas. No
valid run average concentration may exceed the calibration span. To the
extent practicable, the measured emissions should be between 20 to 100
percent of the selected calibration span. This may not be practicable in
some cases of low-concentration measurements or testing for compliance
with an emission limit when emissions are substantially less than the
limit. In such cases, calibration spans that are practicable to
achieving the data quality objectives without being excessively high
should be chosen.
3.5 Centroidal Area means the central area of the stack or duct that
is no greater than 1 percent of the stack or duct cross section. This
area has the same geometric shape as the stack or duct.
3.6 Converter Efficiency Gas means a calibration gas with a known NO
or NO2 concentration and of Traceability Protocol quality.
3.7 Data Recorder means the equipment that permanently records the
concentrations reported by the analyzer.
3.8 Direct Calibration Mode means introducing the calibration gases
directly into the analyzer (or into the assembled measurement system at
a point downstream of all sample conditioning equipment) according to
manufacturer's recommended calibration procedure. This mode of
calibration applies to non-dilution-type measurement systems.
3.9 Drift means the difference between the pre- and post-run system
bias (or system calibration error) checks at a specific calibration gas
concentration level (i.e. low-, mid- or high-).
3.10 Gas Analyzer means the equipment that senses the gas being
measured and generates an output proportional to its concentration.
3.11 Interference Check means the test to detect analyzer responses
to compounds other than the compound of interest, usually a gas present
in the measured gas stream, that is not adequately accounted for in the
calibration procedure and may cause measurement bias.
3.12 Low-Concentration Analyzer means any analyzer that operates
with a calibration span of 20 ppm NOX or lower. Each analyzer
model used routinely to measure low NOX concentrations must
pass a manufacturer's stability test (MST). An MST subjects the analyzer
to a range of line voltages and temperatures that reflect potential
field conditions to demonstrate its stability following
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procedures similar to those provided in 40 CFR 53.23. Ambient-level
analyzers are exempt from the MST requirements of section 16.3. A copy
of this information must be included in each test report. Table 7E-5
lists the criteria to be met.
3.13 Measurement System means all of the equipment used to determine
the NOX concentration. The measurement system comprises six
major subsystems: Sample acquisition, sample transport, sample
conditioning, calibration gas manifold, gas analyzer, and data recorder.
3.14 Response Time means the time it takes the measurement system to
respond to a change in gas concentration occurring at the sampling point
when the system is operating normally at its target sample flow rate or
dilution ratio.
3.15 Run means a series of gas samples taken successively from the
stack or duct. A test normally consists of a specific number of runs.
3.16 System Bias means the difference between a calibration gas
measured in direct calibration mode and in system calibration mode.
System bias is determined before and after each run at the low- and mid-
or high-concentration levels. For dilution-type systems, pre- and post-
run system calibration error is measured rather than system bias.
3.17 System Calibration Error applies to dilution-type systems and
means the difference between the measured concentration of low-, mid-,
or high-level calibration gas and the certified concentration for each
gas when introduced in system calibration mode. For dilution-type
systems, a 3-point system calibration error test is conducted in lieu of
the analyzer calibration error test, and 2-point system calibration
error tests are conducted in lieu of system bias tests.
3.18 System Calibration Mode means introducing the calibration gases
into the measurement system at the probe, upstream of the filter and all
sample conditioning components.
3.19 Test refers to the series of runs required by the applicable
regulation.
4.0 Interferences
Note that interferences may vary among instruments and that
instrument-specific interferences must be evaluated through the
interference test.
5.0 Safety
What safety measures should I consider when using this method? This
method may require you to work with hazardous materials and in hazardous
conditions. We encourage you to establish safety procedures before using
the method. Among other precautions, you should become familiar with the
safety recommendations in the gas analyzer user's manual. Occupational
Safety and Health Administration (OSHA) regulations concerning cylinder
and noxious gases may apply. Nitric oxide and NO2 are toxic
and dangerous gases. Nitric oxide is immediately converted to
NO2 upon reaction with air. Nitrogen dioxide is a highly
poisonous and insidious gas. Inflammation of the lungs from exposure may
cause only slight pain or pass unnoticed, but the resulting edema
several days later may cause death. A concentration of 100 ppm is
dangerous for even a short exposure, and 200 ppm may be fatal.
Calibration gases must be handled with utmost care and with adequate
ventilation. Emission-level exposure to these gases should be avoided.
6.0 Equipment and Supplies
The performance criteria in this method will be met or exceeded if
you are properly using equipment designed for this application.
6.1 What do I need for the measurement system? You may use any
equipment and supplies meeting the following specifications:
(1) Sampling system components that are not evaluated in the system
bias or system calibration error test must be glass, Teflon, or
stainless steel. Other materials are potentially acceptable, subject to
approval by the Administrator.
(2) The interference, calibration error, and system bias criteria
must be met.
(3) Sample flow rate must be maintained within 10 percent of the
flow rate at which the system response time was measured.
(4) All system components (excluding sample conditioning components,
if used) must maintain the sample temperature above the moisture dew
point. Ensure minimal contact between any condensate and the sample gas.
Section 6.2 provides example equipment specifications for a
NOX measurement system. Figure 7E-1 is a diagram of an
example dry-basis measurement system that is likely to meet the method
requirements and is provided as guidance. For wet-basis systems, you may
use alternative equipment and supplies as needed (some of which are
described in Section 6.2), provided that the measurement system meets
the applicable performance specifications of this method.
6.2 Measurement System Components
6.2.1 Sample Probe. Glass, stainless steel, or other approved
material, of sufficient length to traverse the sample points.
6.2.2 Particulate Filter. An in-stack or out-of-stack filter. The
filter must be made of material that is non-reactive to the gas being
sampled. The filter media for out-of-stack filters must be included in
the system bias test. The particulate filter requirement may be waived
in applications where no significant particulate matter is expected
(e.g., for emission testing of a combustion turbine firing natural gas).
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6.2.3 Sample Line. The sample line from the probe to the
conditioning system/sample pump should be made of Teflon or other
material that does not absorb or otherwise alter the sample gas. For a
dry-basis measurement system (as shown in Figure 7E-1), the temperature
of the sample line must be maintained at a sufficiently high level to
prevent condensation before the sample conditioning components. For wet-
basis measurement systems, the temperature of the sample line must be
maintained at a sufficiently high level to prevent condensation before
the analyzer.
6.2.4 Conditioning Equipment. For dry basis measurements, a
condenser, dryer or other suitable device is required to remove moisture
continuously from the sample gas. Any equipment needed to heat the probe
or sample line to avoid condensation prior to the sample conditioning
component is also required.
For wet basis systems, you must keep the sample above its dew point
either by: (1) Heating the sample line and all sample transport
components up to the inlet of the analyzer (and, for hot-wet extractive
systems, also heating the analyzer) or (2) by diluting the sample prior
to analysis using a dilution probe system. The components required to do
either of the above are considered to be conditioning equipment.
6.2.5 Sampling Pump. For systems similar to the one shown in Figure
7E-1, a leak-free pump is needed to pull the sample gas through the
system at a flow rate sufficient to minimize the response time of the
measurement system. The pump may be constructed of any material that is
non-reactive to the gas being sampled. For dilution-type measurement
systems, an ejector pump (eductor) is used to create a vacuum that draws
the sample through a critical orifice at a constant rate.
6.2.6 Calibration Gas Manifold. Prepare a system to allow the
introduction of calibration gases either directly to the gas analyzer in
direct calibration mode or into the measurement system, at the probe, in
system calibration mode, or both, depending upon the type of system
used. In system calibration mode, the system should be able to flood the
sampling probe and vent excess gas. Alternatively, calibration gases may
be introduced at the calibration valve following the probe. Maintain a
constant pressure in the gas manifold. For in-stack dilution-type
systems, a gas dilution subsystem is required to transport large volumes
of purified air to the sample probe and a probe controller is needed to
maintain the proper dilution ratio.
6.2.7 Sample Gas Manifold. For the type of system shown in Figure
7E-1, the sample gas manifold diverts a portion of the sample to the
analyzer, delivering the remainder to the by-pass discharge vent. The
manifold should also be able to introduce calibration gases directly to
the analyzer (except for dilution-type systems). The manifold must be
made of material that is non-reactive to the gas sampled or the
calibration gas and be configured to safely discharge the bypass gas.
6.2.8 NOX Analyzer. An instrument that continuously measures
NOX in the gas stream and meets the applicable specifications
in section 13.0. An analyzer that operates on the principle of
chemiluminescence with an NO2 to NO converter is one example
of an analyzer that has been used successfully in the past. Analyzers
operating on other principles may also be used provided the performance
criteria in section 13.0 are met.
6.2.8.1 Dual Range Analyzers. For certain applications, a wide range
of gas concentrations may be encountered, necessitating the use of two
measurement ranges. Dual-range analyzers are readily available for these
applications. These analyzers are often equipped with automated range-
switching capability, so that when readings exceed the full-scale of the
low measurement range, they are recorded on the high range. As an
alternative to using a dual-range analyzer, you may use two segments of
a single, large measurement scale to serve as the low and high ranges.
In all cases, when two ranges are used, you must quality-assure both
ranges using the proper sets of calibration gases. You must also meet
the interference, calibration error, system bias, and drift checks.
However, we caution that when you use two segments of a large
measurement scale for dual range purposes, it may be difficult to meet
the performance specifications on the low range due to signal-to-noise
ratio considerations.
6.2.8.2 Low Concentration Analyzer. When an analyzer is routinely
calibrated with a calibration span of 20 ppmv or less, the
manufacturer's stability test (MST) is required. See Table 7E-5 for test
parameters.
6.2.9 Data Recording. A strip chart recorder, computerized data
acquisition system, digital recorder, or data logger for recording
measurement data may be used.
7.0 Reagents and Standards
7.1 Calibration Gas. What calibration gases do I need? Your
calibration gas must be NO in N2 and certified (or
recertified) within an uncertainty of 2.0 percent in accordance with
``EPA Traceability Protocol for Assay and Certification of Gaseous
Calibration Standards'' September 1997, as amended August 25, 1999, EPA-
600/R-97/121. Blended gases meeting the Traceability Protocol are
allowed if the additional gas components are shown not to interfere with
the analysis. If a zero gas is used for the low-level gas, it must meet
the requirements under the definition for ``zero air material'' in 40
CFR 72.2. The calibration gas must not be used after its expiration
date. Except for applications under part 75 of
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this chapter, it is acceptable to prepare calibration gas mixtures from
EPA Traceability Protocol gases in accordance with Method 205 in
appendix M to part 51 of this chapter. For part 75 applications, the use
of Method 205 is subject to the approval of the Administrator. The goal
and recommendation for selecting calibration gases is to bracket the
sample concentrations. The following calibration gas concentrations are
required:
7.1.1 High-Level Gas. This concentration is chosen to set the
calibration span as defined in Section 3.4.
7.1.2 Mid-Level Gas. 40 to 60 percent of the calibration span.
7.1.3 Low-Level Gas. Less than 20 percent of the calibration span.
7.1.4 Converter Efficiency Gas. What reagents do I need for the
converter efficiency test? The converter efficiency gas is a
manufacturer-certified gas with a concentration sufficient to show
NO2 conversion at the concentrations encountered in the
source. A test gas concentration in the 40 to 60 ppm range is suggested,
but other concentrations may be more appropriate to specific sources.
For the test described in section 8.2.4.1, NO2 is required.
For the alternative converter efficiency tests in section 16.2, NO is
required.
7.2 Interference Check. What reagents do I need for the interference
check? Use the appropriate test gases listed in Table 7E-3 or others not
listed that can potentially interfere (as indicated by the test facility
type, instrument manufacturer, etc.) to conduct the interference check.
These gases should be manufacturer certified but do not have to be
prepared by the EPA traceability protocol.
8.0 Sample Collection, Preservation, Storage, and Transport
Emission Test Procedure
Since you are allowed to choose different options to comply with
some of the performance criteria, it is your responsibility to identify
the specific options you have chosen, to document that the performance
criteria for that option have been met, and to identify any deviations
from the method.
8.1 What sampling site and sampling points do I select?
8.1.1 Unless otherwise specified in an applicable regulation or by
the Administrator, when this method is used to determine compliance with
an emission standard, conduct a stratification test as described in
section 8.1.2 to determine the sampling traverse points to be used. For
performance testing of continuous emission monitoring systems, follow
the sampling site selection and traverse point layout procedures
described in the appropriate performance specification or applicable
regulation (e.g., Performance Specification 2 in appendix B to this
part).
8.1.2 Determination of Stratification. Perform a stratification test
at each test site to determine the appropriate number of sample traverse
points. If testing for multiple pollutants or diluents at the same site,
a stratification test using only one pollutant or diluent satisfies this
requirement. A stratification test is not required for small stacks that
are less than 4 inches in diameter. To test for stratification, use a
probe of appropriate length to measure the NOX (or pollutant
of interest) concentration at 12 traverse points located according to
Table 1-1 or Table 1-2 of Method 1. Alternatively, you may measure at
three points on a line passing through the centroidal area. Space the
three points at 16.7, 50.0, and 83.3 percent of the measurement line.
Sample for a minimum of twice the system response time (see section
8.2.6) at each traverse point. Calculate the individual point and mean
NOX concentrations. If the concentration at each traverse
point differs from the mean concentration for all traverse points by no
more than: 5.0 percent of the mean concentration;
or 0.5 ppm (whichever is less restrictive), the
gas stream is considered unstratified, and you may collect samples from
a single point that most closely matches the mean. If the 5.0 percent or
0.5 ppm criterion is not met, but the concentration at each traverse
point differs from the mean concentration for all traverse points by not
more than: 10.0 percent of the mean concentration;
or 1.0 ppm (whichever is less restrictive), the
gas stream is considered to be minimally stratified and you may take
samples from three points. Space the three points at 16.7, 50.0, and
83.3 percent of the measurement line. Alternatively, if a 12-point
stratification test was performed and the emissions were shown to be
minimally stratified (all points within 10.0
percent of their mean or within