[Title 40 CFR 53.61]
[Code of Federal Regulations (annual edition) - July 1, 2002 Edition]
[Title 40 - PROTECTION OF ENVIRONMENT]
[Chapter I - ENVIRONMENTAL PROTECTION AGENCY]
[Subchapter C - AIR PROGRAMS (CONTINUED)]
[Part 53 - AMBIENT AIR MONITORING REFERENCE AND EQUIVALENT METHODS]
[Subpart F - Procedures for Testing Performance Characteristics of Class]
[Sec. 53.61 - Test conditions for PM2.5 reference method equivalency.]
[From the U.S. Government Printing Office]
40PROTECTION OF ENVIRONMENT52002-07-012002-07-01falseTest conditions for PM<INF>2.5</INF> reference method equivalency.53.61Sec. 53.61PROTECTION OF ENVIRONMENTENVIRONMENTAL PROTECTION AGENCYAIR PROGRAMS (CONTINUED)AMBIENT AIR MONITORING REFERENCE AND EQUIVALENT METHODSProcedures for Testing Performance Characteristics of Class
Sec. 53.61 Test conditions for PM2.5 reference method equivalency.
(a) Sampler surface preparation. Internal surfaces of the candidate
sampler shall be cleaned and dried prior to performing any Class II
sampler test in this subpart. The internal collection surfaces of the
sampler shall then be prepared in strict accordance with the operating
instructions specified in the sampler's operating manual referred to in
section 7.4.18 of 40 CFR part 50, appendix L.
(b) Sampler setup. Set up and start up of all test samplers shall be
in strict accordance with the operating instructions specified in the
manual referred to in section 7.4.18 of 40 CFR part 50, appendix L,
unless otherwise specified within this subpart.
(c) Sampler adjustments. Once the test sampler or samplers have been
set up and the performance tests started, manual adjustment shall be
permitted only between test points for all applicable tests. Manual
adjustments and any periodic maintenance shall be limited to only those
procedures prescribed in the manual referred to in section 7.4.18 of 40
CFR part 50, appendix L. The submitted records shall clearly indicate
when any manual adjustment or periodic maintenance was made and shall
describe the operations performed.
(d) Sampler malfunctions. If a test sampler malfunctions during any
of the applicable tests, that test run shall be repeated. A detailed
explanation of all malfunctions and the remedial actions taken shall be
submitted as part of the equivalent method application.
(e) Particle concentration measurements. All measurements of
particle concentration must be made such that the relative error in
measurement is less than 5.0 percent. Relative error is defined as (s x
100 percent)/(X), where s is the sample standard deviation of the
particle concentration detector, X is the measured concentration, and
the units of s and X are identical.
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(f) Operation of test measurement equipment. All test measurement
equipment shall be set up, calibrated, and maintained by qualified
personnel according to the manufacturer's instructions. All appropriate
calibration information and manuals for this equipment shall be kept on
file.
(g) Vibrating orifice aerosol generator conventions. This section
prescribes conventions regarding the use of the vibrating orifice
aerosol generator (VOAG) for the size-selective performance tests
outlined in Secs. 53.62, 53.63, 53.64, and 53.65.
(1) Particle aerodynamic diameter. The VOAG produces near-
monodisperse droplets through the controlled breakup of a liquid jet.
When the liquid solution consists of a non-volatile solute dissolved in
a volatile solvent, the droplets dry to form particles of near-
monodisperse size.
(i) The physical diameter of a generated spherical particle can be
calculated from the operating parameters of the VOAG as:
Equation 1
[GRAPHIC] [TIFF OMITTED] TR18JY97.094
where:
Dp = particle physical diameter, [mu]m;
Q = liquid volumetric flow rate, [mu]m3/sec;
Cvol = volume concentration (particle volume produced per
drop volume), dimensionless; and
f = frequency of applied vibrational signal, 1/sec.
(ii) A given particle's aerodynamic behavior is a function of its
physical particle size, particle shape, and density. Aerodynamic
diameter is defined as the diameter of a unit density ([rho]o
= 1g/cm3) sphere having the same settling velocity as the
particle under consideration. For converting a spherical particle of
known density to aerodynamic diameter, the governing relationship is:
Equation 2
[GRAPHIC] [TIFF OMITTED] TR18JY97.095
where:
Dae = particle aerodynamic diameter, [mu]m;
[rho]p = particle density, g/cm3;
[rho]o = aerodynamic particle density = 1 g/cm3;
CDp = Cunningham's slip correction factor for physical
particle diameter, dimensionless; and
CDae = Cunningham's slip correction factor for aerodynamic
particle diameter, dimensionless.
(iii) At room temperature and standard pressure, the Cunningham's
slip correction factor is solely a function of particle diameter:
Equation 3
[GRAPHIC] [TIFF OMITTED] TR18JY97.096
or
Equation 4
[GRAPHIC] [TIFF OMITTED] TR18JY97.097
(iv) Since the slip correction factor is itself a function of
particle diameter, the aerodynamic diameter in equation 2 of paragraph
(g)(1)(ii) of this section cannot be solved directly but must be
determined by iteration.
(2) Solid particle generation. (i) Solid particle tests performed in
this subpart shall be conducted using particles composed of ammonium
fluorescein. For use in the VOAG, liquid solutions of known volumetric
concentration can be prepared by diluting fluorescein powder
(C20H12O5, FW = 332.31, CAS 2321-07-5)
with aqueous ammonia. Guidelines for preparation of fluorescein
solutions of the desired volume concentration (Cvol) are
presented by Vanderpool and Rubow (1988) (Reference 2 in appendix A of
this subpart). For purposes of converting particle
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physical diameter to aerodynamic diameter, an ammonium fluorescein
density of 1.35 g/cm3 shall be used.
(ii) Mass deposits of ammonium fluorescein shall be extracted and
analyzed using solutions of 0.01 N ammonium hydroxide.
(3) Liquid particle generation. (i) Tests prescribed in Sec. 53.63
for inlet aspiration require the use of liquid particle tests composed
of oleic acid tagged with uranine to enable subsequent fluorometric
quantitation of collected aerosol mass deposits. Oleic acid
(C18H34O2, FW = 282.47, CAS 112-80-1)
has a density of 0.8935 g/cm3. Because the viscosity of oleic
acid is relatively high, significant errors can occur when dispensing
oleic acid using volumetric pipettes. For this reason, it is recommended
that oleic acid solutions be prepared by quantifying dispensed oleic
acid gravimetrically. The volume of oleic acid dispensed can then be
calculated simply by dividing the dispensed mass by the oleic acid
density.
(ii) Oleic acid solutions tagged with uranine shall be prepared as
follows. A known mass of oleic acid shall first be diluted using
absolute ethanol. The desired mass of the uranine tag should then be
diluted in a separate container using absolute ethanol. Uranine
(C20H10O5Na2, FW = 376.3,
CAS 518-47-8) is the disodium salt of fluorescein and has a density of
1.53 g/cm3. In preparing uranine tagged oleic acid particles,
the uranine content shall not exceed 20 percent on a mass basis. Once
both oleic acid and uranine solutions are properly prepared, they can
then be combined and diluted to final volume using absolute ethanol.
(iii) Calculation of the physical diameter of the particles produced
by the VOAG requires knowledge of the liquid solution's volume
concentration (Cvol). Because uranine is essentially
insoluble in oleic acid, the total particle volume is the sum of the
oleic acid volume and the uranine volume. The volume concentration of
the liquid solution shall be calculated as:
Equation 5
[GRAPHIC] [TIFF OMITTED] TR18JY97.098
where:
Vu = uranine volume, ml;
Voleic = oleic acid volume, ml;
Vsol = total solution volume, ml;
Mu = uranine mass, g;
[rho]u = uranine density, g/cm3;
Moleic = oleic acid mass, g; and
[rho]oleic = oleic acid density, g/cm3.
(iv) For purposes of converting the particles' physical diameter to
aerodynamic diameter, the density of the generated particles shall be
calculated as:
Equation 6
[GRAPHIC] [TIFF OMITTED] TR18JY97.099
(v) Mass deposits of oleic acid shall be extracted and analyzed
using solutions of 0.01 N sodium hydroxide.
[62 FR 38814, July 18, 1997; 63 FR 7714, Feb. 17, 1998]