# Title 40

## SECTION 53.64

### 53.64 Test procedure: Static fractionator test.

§ 53.64 Test procedure: Static fractionator test.(a) *Overview.* This test applies only to those candidate
methods in which the sole deviation from the reference method is in
the design of the 2.5-micron fractionation device. The purpose of
this test is to ensure that the fractionation characteristics of
the candidate fractionator are acceptably similar to that of the
reference method sampler. It is recognized that various
methodologies exist for quantifying fractionator effectiveness. The
following commonly-employed techniques are provided for purposes of
guidance. Other methodologies for determining sampler effectiveness
may be used contingent upon prior approval by the Agency.

(1) *Wash-off method.* Effectiveness is determined by
measuring the aerosol mass deposited on the candidate sampler's
after filter versus the aerosol mass deposited in the fractionator.
The material deposited in the fractionator is recovered by washing
its internal surfaces. For these wash-off tests, a fluorometer must
be used to quantitate the aerosol concentration. Note that if this
technique is chosen, the candidate must be reloaded with coarse
aerosol prior to each test point when reevaluating the curve as
specified in the loading test.

(2) *Static chamber method.* Effectiveness is determined by
measuring the aerosol mass concentration sampled by the candidate
sampler's after filter versus that which exists in a static
chamber. A calibrated fluorometer shall be used to quantify the
collected aerosol deposits. The aerosol concentration is calculated
as the measured aerosol mass divided by the sampled air volume.

(3) *Divided flow method.* Effectiveness is determined by
comparing the aerosol concentration upstream of the candidate
sampler's fractionator versus that concentration which exists
downstream of the candidate fractionator. These tests may utilize
either fluorometry or a real-time aerosol measuring device to
determine the aerosol concentration.

(b) *Technical definition.* Effectiveness under static
conditions is the ratio (expressed as a percentage) of the mass
concentration of particles of a given size reaching the sampler
filter to the mass concentration of particles of the same size
existing in the test atmosphere.

(c) *Facilities and equipment required* - (1) *Aerosol
generation.* Methods for generating aerosols shall be identical
to those prescribed in § 53.62(c)(2).

(2) *Particle delivery system.* Acceptable apparatus for
delivering the generated aerosols to the candidate fractionator is
dependent on the effectiveness measurement methodology and shall be
defined as follows:

(i) *Wash-off test apparatus.* The aerosol may be delivered
to the candidate fractionator through direct piping (with or
without an in-line mixing chamber). Validation particle size and
quality shall be conducted at a point directly upstream of the
fractionator.

(ii) *Static chamber test apparatus.* The aerosol shall be
introduced into a chamber and sufficiently mixed such that the
aerosol concentration within the chamber is spatially uniform. The
chamber must be of sufficient size to house at least four total
filter samplers in addition to the inlet of the candidate method
size fractionator. Validation of particle size and quality shall be
conducted on representative aerosol samples extracted from the
chamber.

(iii) *Divided flow test apparatus.* The apparatus shall
allow the aerosol concentration to be measured upstream and
downstream of the fractionator. The aerosol shall be delivered to a
manifold with two symmetrical branching legs. One of the legs,
referred to as the bypass leg, shall allow the challenge aerosol to
pass unfractionated to the detector. The other leg shall
accommodate the fractionation device.

(3) *Particle concentration measurement* - (i)
*Fluorometry.* Refer to § 53.62(c)(7).

(ii) *Number concentration measurement.* A number counting
particle sizer may be used in conjunction with the divided flow
test apparatus in lieu of fluorometric measurement. This device
must have a minimum range of 1 to 10 µm, a resolution of 0.1 µm,
and an accuracy of 0.15 µm such that primary particles may be
distinguished from multiplets for all test aerosols. The
measurement of number concentration shall be accomplished by
integrating the primary particle peak.

(d) *Setup* - (1) *Remove the inlet and downtube from the
candidate fractionator.* All tests procedures shall be conducted
with the inlet and downtube removed from the candidate sampler.

(2) *Surface treatment of the fractionator.* Rinsing
aluminum surfaces with alkaline solutions has been found to
adversely affect subsequent fluorometric quantitation of aerosol
mass deposits. If wash-off tests are to be used for quantifying
aerosol penetration, internal surfaces of the fractionator must
first be plated with electroless nickel. Specifications for this
plating are specified in Society of Automotive Engineers Aerospace
Material Specification (SAE AMS) 2404C, Electroless Nickel Plating
(Reference 3 in appendix A of subpart F).

(e) *Test procedure: Wash-off method* - (1) *Clean the
candidate sampler.* Note: The procedures in this step may be
omitted if this test is being used to evaluate the fractionator
after being loaded as specified in § 53.65.

(i) Clean and dry the internal surfaces of the candidate sampler.

(ii) Prepare the internal fractionator surfaces 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.

(2) *Generate aerosol.* Follow the procedures for aerosol
generation prescribed in § 53.62(d)(2).

(3) *Verify the quality of the test aerosol.* Follow the
procedures for verification of test aerosol size and quality
prescribed in § 53.62(d)(4).

(4) *Determine effectiveness for the particle size being
produced.* (i) Collect particles downstream of the fractionator
on an appropriate filter over a time period such that the relative
error of the fluorometric measurement is less than 5.0 percent.

(ii) Determine the quantity of material collected on the after filter of the candidate method using a calibrated fluorometer. Calculate and record the aerosol mass concentration for the sampler filter as:

Equation 20 where: i = replicate number; Mcand = mass of material collected with the candidate sampler; Q = candidate sampler volumetric flowrate; and t = sampling time.(iii) Wash all interior surfaces upstream of the filter and determine the quantity of material collected using a calibrated fluorometer. Calculate and record the fluorometric mass concentration of the sampler wash as:

Equation 21 where: i = replicate number; Mwash = mass of material washed from the interior surfaces of the fractionator; Q = candidate sampler volumetric flowrate; and t = sampling time.(iv) Calculate and record the sampling effectiveness of the test sampler for this particle size as:

Equation 22 where: i = replicate number.(v) Repeat steps in paragraphs (e)(4) of this section, as appropriate, to obtain a minimum of three replicate measurements of sampling effectiveness. Note: The procedures for loading the candidate in § 53.65 must be repeated between repetitions if this test is being used to evaluate the fractionator after being loaded as specified in § 53.65.

(vi) Calculate and record the average sampling effectiveness of the test sampler as:

Equation 23 where: i = replicate number; and n = number of replicates.(vii)(A) Calculate and record the coefficient of variation for the replicate sampling effectiveness measurements of the test sampler as:

Equation 24 where: i = replicate number; and n = total number of measurements.(B) If the value of CVE exceeds 10 percent, then steps in paragraphs (e) (2) through (e)(4) of this section must be repeated.

(5) Repeat steps in paragraphs (e) (1) through (e)(4) of this section for each particle size specified in table F-2 of this subpart.

(f) *Test procedure: Static chamber method* - (1)
*Generate aerosol.* Follow the procedures for aerosol
generation prescribed in § 53.62(d)(2).

(2) *Verify the quality of the test aerosol.* Follow the
procedures for verification of test aerosol size and quality
prescribed in § 53.62(d)(4).

(3) *Introduce particles into chamber.* Introduce the
particles into the static chamber and allow the particle
concentration to stabilize.

(4) *Install and operate the candidate sampler's fractionator
and its after-filter and at least four total filters.* (i)
Install the fractionator and an array of four or more equally
spaced total filter samplers such that the total filters surround
and are in the same plane as the inlet of the fractionator.

(ii) Simultaneously collect particles onto appropriate filters with the total filter samplers and the fractionator for a time period such that the relative error of the measured concentration is less than 5.0 percent.

(5) *Calculate the aerosol spatial uniformity in the
chamber.* (i) Determine the quantity of material collected with
each total filter sampler in the array using a calibrated
fluorometer. Calculate and record the mass concentration for each
total filter sampler as:

(ii) Calculate and record the mean mass concentration as:

Equation 26 where: n = total number of samplers; i = replicate number; and j = filter sampler number.(iii) (A) Calculate and record the coefficient of variation of the total mass concentration as:

Equation 27 where: i = replicate number; j = total filter sampler number; and n = number of total filter samplers.(B) If the value of CVtotal exceeds 10 percent, then the particle concentration uniformity is unacceptable, alterations to the static chamber test apparatus must be made, and steps in paragraphs (f)(1) through (f)(5) of this section must be repeated.

(6) *Determine the effectiveness of the candidate sampler.*
(i) Determine the quantity of material collected on the candidate
sampler's after filter using a calibrated fluorometer. Calculate
and record the mass concentration for the candidate sampler as:

(ii) Calculate and record the sampling effectiveness of the candidate sampler as:

Equation 29 where: i = replicate number.(iii) Repeat step in paragraph (f)(4) through (f)(6) of this section, as appropriate, to obtain a minimum of three replicate measurements of sampling effectiveness.

(iv) Calculate and record the average sampling effectiveness of the test sampler as:

Equation 30 where: i= replicate number.(v)(A) Calculate and record the coefficient of variation for the replicate sampling effectiveness measurements of the test sampler as:

Equation 31 where: i = replicate number; and n = number of measurements of effectiveness.(B) If the value of CVE exceeds 10 percent, then the test run (steps in paragraphs (f)(2) through (f)(6) of this section) is unacceptable and must be repeated.

(7) Repeat steps in paragraphs (f)(1) through (f)(6) of this section for each particle size specified in table F-2 of this subpart.

(g) *Test procedure: Divided flow method* - (1) *Generate
calibration aerosol.* Follow the procedures for aerosol
generation prescribed in § 53.62(d)(2).

(2) *Verify the quality of the calibration aerosol.* Follow
the procedures for verification of calibration aerosol size and
quality prescribed in § 53.62(d)(4).

(3) *Introduce aerosol.* Introduce the calibration aerosol
into the static chamber and allow the particle concentration to
stabilize.

(4) *Validate that transport is equal for the divided flow
option.* (i) With fluorometry as a detector:

(A) Install a total filter on each leg of the divided flow apparatus.

(B) Collect particles simultaneously through both legs at 16.7 L/min onto an appropriate filter for a time period such that the relative error of the measured concentration is less than 5.0 percent.

(C) Determine the quantity of material collected on each filter using a calibrated fluorometer. Calculate and record the mass concentration measured in each leg as:

Equation 32 where: i = replicate number, M = mass of material collected with the total filter; and Q = candidate sampler volumetric flowrate.(D) Repeat steps in paragraphs (g)(4)(i)(A) through (g)(4)(i)(C) of this section until a minimum of three replicate measurements are performed.

(ii) With an aerosol number counting device as a detector:

(A) Remove all flow obstructions from the flow paths of the two legs.

(B) Quantify the aerosol concentration of the primary particles in each leg of the apparatus.

(C) Repeat steps in paragraphs (g)(4)(ii)(A) through (g)(4)(ii)(B) of this section until a minimum of three replicate measurements are performed.

(iii) (A) Calculate the mean concentration and coefficient of variation as:

Equation 33 Equation 34 where: i = replicate number; and n = number of replicates.(B) If the measured mean concentrations through the two legs do not agree within 5 percent, then adjustments may be made in the setup, and this step must be repeated.

(5) *Determine effectiveness.* Determine the sampling
effectiveness of the test sampler with the inlet removed by one of
the following procedures:

(i) With fluorometry as a detector:

(A) Prepare the divided flow apparatus for particle collection. Install a total filter into the bypass leg of the divided flow apparatus. Install the particle size fractionator with a total filter placed immediately downstream of it into the other leg.

(B) Collect particles simultaneously through both legs at 16.7 L/min onto appropriate filters for a time period such that the relative error of the measured concentration is less than 5.0 percent.

(C) Determine the quantity of material collected on each filter using a calibrated fluorometer. Calculate and record the mass concentration measured by the total filter and that measured after penetrating through the candidate fractionator as follows:

Equation 35 Equation 36 where: i = replicate number.(ii) With a number counting device as a detector:

(A) Install the particle size fractionator into one of the legs of the divided flow apparatus.

(B) Quantify and record the aerosol number concentration of the primary particles passing through the fractionator as Ccand(i).

(C) Divert the flow from the leg containing the candidate fractionator to the bypass leg. Allow sufficient time for the aerosol concentration to stabilize.

(D) Quantify and record the aerosol number concentration of the primary particles passing through the bypass leg as Ctotal(i).

(iii) Calculate and record sampling effectiveness of the candidate sampler as:

Equation 37 where: i = replicate number.(6) Repeat step in paragraph (g)(5) of this section, as appropriate, to obtain a minimum of three replicate measurements of sampling effectiveness.

(7) *Calculate the mean and coefficient of variation for
replicate measurements of effectiveness.* (i) Calculate and
record the mean sampling effectiveness of the candidate sampler
as:

(ii)(A) Calculate and record the coefficient of variation for the replicate sampling effectiveness measurements of the candidate sampler as:

Equation 39 where: i = replicate number; and n = number of replicates.(B) If the coefficient of variation is not less than 10 percent, then the test run must be repeated (steps in paragraphs (g)(1) through (g)(7) of this section).

(8) Repeat steps in paragraphs (g)(1) through (g)(7) of this section for each particle size specified in table F-2 of this subpart.

(h) *Calculations* - (1) *Treatment of multiplets.*
For all measurements made by fluorometric analysis, data shall be
corrected for the presence of multiplets as described in §
53.62(f)(1). Data collected using a real-time device (as described
in paragraph (c)(3)(ii)) of this section will not require multiplet
correction.

(2) *Cutpoint determination.* For each wind speed determine
the sampler Dp50 cutpoint defined as the aerodynamic particle size
corresponding to 50 percent effectiveness from the multiplet
corrected smooth curve.

(3) *Graphical analysis and numerical integration with ambient
distributions.* Follow the steps outlined in § 53.62 (e)(3)
through (e)(4) to calculate the estimated concentration measurement
ratio between the candidate sampler and a reference method
sampler.

(i) *Test evaluation.* The candidate method passes the
static fractionator test if the values of Rc and Dp50 for each
distribution meets the specifications in table F-1 of this
subpart.