# Title 40

## SECTION 53.34

### 53.34 Test procedure for methods for PM10 and Class I methods for PM 2.5.

§ 53.34 Test procedure for methods for PM10 and Class I methods for PM 2.5.(a) *Comparability.* Comparability is shown for PM 10
methods and for Class I methods for PM 2.5 when the relationship
between:

(1) Measurements made by a candidate method, and

(2) Measurements made by a corresponding reference method on simultaneously collected samples (or the same sample, if applicable) at each of one or more test sites (as required) is such that the linear regression parameters (slope, intercept, and correlation coefficient) describing the relationship meet the requirements specified in table C-4 of this subpart.

(b) *Methods for PM*10. Test measurements must be made, or
derived from particulate samples collected, at not less than two
test sites, each of which must be located in a geographical area
characterized by ambient particulate matter that is significantly
different in nature and composition from that at the other test
site(s). Augmentation of pollutant concentrations is not permitted,
hence appropriate test sites must be selected to provide the
minimum number of test PM 10 concentrations in the ranges specified
in table C-4 of this subpart. The tests at the two sites may be
conducted in different calendar seasons, if appropriate, to provide
PM 10 concentrations in the specified ranges.

(c) *PM*10 *methods employing the same sampling procedure
as the reference method but a different analytical method.*
Candidate methods for PM 10 which employ a sampler and sample
collection procedure that are identical to the sampler and sample
collection procedure specified in the reference method, but use a
different analytical procedure, may be tested by analyzing common
samples. The common samples shall be collected according to the
sample collection procedure specified by the reference method and
shall be analyzed in accordance with the analytical procedures of
both the candidate method and the reference method.

(d) *Methods for PM*2.5. Augmentation of pollutant
concentrations is not permitted, hence appropriate test sites must
be selected to provide the minimum number of test measurement sets
to meet the requirements for PM 2.5 concentrations in the ranges
specified in table C-4 of this subpart. Only one test site is
required, and the site need only meet the PM 2.5 ambient
concentration levels required by table C-4 of this subpart and the
requirements of § 53.30(b) of this subpart. A total of 10 valid
measurement sets is required.

(e) *Collocated measurements.* (1) Set up three reference
method samplers collocated with three candidate method samplers or
analyzers at each of the number of test sites specified in table
C-4 of this subpart.

(2) The ambient air intake points of all the candidate and reference method collocated samplers or analyzers shall be positioned at the same height above the ground level, and between 2 meters (1 meter for samplers or analyzers with flow rates less than 200 L/min) and 4 meters apart. The samplers shall be oriented in a manner that will minimize spatial and wind directional effects on sample collection.

(3) At each site, obtain as many sets of simultaneous PM 10 or PM 2.5 measurements as necessary (see table C-4 of this subpart), each set consisting of three reference method and three candidate method measurements, all obtained simultaneously.

(4) Candidate PM 10 method measurements shall be nominal 24-hour (±1 hour) integrated measurements or shall be averaged to obtain the mean concentration for a nominal 24-hour period. PM 2.5 measurements may be either nominal 24-or 48-hour integrated measurements. All collocated measurements in a measurement set must cover the same nominal 24-or 48-hour time period.

(5) For samplers, retrieve the samples promptly after sample collection and analyze each sample according to the reference method or candidate method, as appropriate, and determine the PM 10 or PM 2.5 concentration in µg/m 3. If the conditions of paragraph (c) of this section apply, collect sample sets only with the three reference method samplers. Guidance for quality assurance procedures for PM 2.5 methods is found in “Quality Assurance Document 2.12” (reference (2) in appendix A to this subpart).

(f) *Sequential samplers.* For sequential samplers, the
sampler shall be configured for the maximum number of sequential
samples and shall be set for automatic collection of all samples
sequentially such that the test samples are collected equally, to
the extent possible, among all available sequential channels or
utilizing the full available sequential capability.

(g) *Calculation of reference method averages and
precisions.* (1) For each of the measurement sets, calculate the
average PM 10 or PM 2.5 concentration obtained with the reference
method samplers, using equation 7 of this section:

(2) For each of the measurement sets, calculate the precision of the reference method PM 10 or PM 2.5 measurements as the standard deviation, PRj, using equation 8 of this section:

(3) For each measurement set, also calculate the precision of the reference method PM 10 or PM 2.5 measurements as the relative standard deviation, RPRj, in percent, using equation 9 of this section:

(h) *Acceptability of measurement sets.* Each measurement
set is acceptable and valid only if the three reference method
measurements and the three candidate method measurements are
obtained and are valid, R j falls within the acceptable
concentration range specified in table C-4 of this subpart, and
either PRj or RPRj is within the corresponding limit for reference
method precision specified in table C-4 of this subpart. For each
site, table C-4 of this subpart specifies the minimum number of
measurement sets required having R j above and below specified
concentrations for 24- or 48-hour samples. Additional measurement
sets shall be obtained, as necessary, to provide the minimum number
of acceptable measurement sets for each category and the minimum
total number of acceptable measurement sets for each test site. If
more than the minimum number of measurement sets are collected that
meet the acceptability criteria, all such measurement sets shall be
used to demonstrate comparability.

(i) *Candidate method average concentration measurement.*
For each of the acceptable measurement sets, calculate the average
PM 10 or PM 2.5 concentration measurements obtained with the
candidate method samplers, using equation 10 of this section:

(j) *Test for comparability.* (1) For each site, plot all
of the average PM 10 or PM 2.5 measurements obtained with the
candidate method (C j) against the corresponding average PM 10 or
PM 2.5 measurements obtained with the reference method (R j. For
each site, calculate and record the linear regression slope and
intercept, and the correlation coefficient.

(2) To pass the test for comparability, the slope, intercept, and correlation coefficient calculated under paragraph (j)(1) of this section must be within the limits specified in table C-4 of this subpart for all test sites.