Standard Practice for Evaluating the Performance of Respirable Aerosol Samplers

SIGNIFICANCE AND USE
This practice is significant for determining performance relative to ideal sampling conventions. The purposes are multifold:
The conventions have a recognized tie to health effects and can easily be adjusted to accommodate new findings.
Performance criteria permit instrument designers to seek practical sampler improvements.
Performance criteria promote continued experimental testing of the samplers in use with the result that the significant variables (such as wind speed, particle charge, etc.) affecting sampler operation become understood.
One specific use of the performance tests is in determining the efficacy of a given candidate sampler for application in regulatory sampling. The accuracy of the candidate sampler is measured in accordance with the evaluation tests given here. A sampler may then be adopted for a specific application if the accuracy is better than a specific value.
5.2.1 Discussion—In some instances, a sampler so selected for use in compliance determinations is specified within an exposure standard. This is done so as to eliminate differences among similar samplers. Sampler specification then replaces the respirable sampling convention, eliminating bias (3.2.10), which then does not appear in the uncertainty budget.
Although the criteria are presented in terms of accepted sampling conventions geared mainly to compliance sampling, other applications exist as well. For example, suppose that a specific aerosol diameter-dependent health effect is under investigation. Then for the purpose of an epidemiological study an aerosol sampler that reflects the diameter dependence of interest is required. Sampler accuracy may then be determined relative to a modified sampling convention.
SCOPE
1.1 This practice covers the evaluation of the performance of personal samplers of non-fibrous respirable aerosol. The samplers are assessed relative to a specific respirable sampling convention. The convention is one of several that identify specific particle size fractions for assessing health effects of airborne particles. When a health effects assessment has been based on a specific convention it is appropriate to use that same convention for setting permissible exposure limits in the workplace and ambient environment and for monitoring compliance. The conventions, which define inhalable, thoracic, and respirable aerosol sampler ideals, have now been adopted by the International Standards Organization (ISO 7708), the Comité Européen de Normalisation (CEN Standard EN 481), and the American Conference of Governmental Industrial Hygienists (ACGIH, Ref  (1)), developed  (2) in part from health-effects studies reviewed in Ref (3) and in part as a compromise between definitions proposed in Refs (3,4).
1.2 This practice is complementary to Test Method D4532, which specifies a particular instrument, the 10-mm cyclone. The sampler evaluation procedures presented in this practice have been applied in the testing of the 10-mm cyclone as well as the Higgins-Dewell cyclone. , Details on the evaluation have been published (5-7)  and can be incorporated into revisions of Test Method D4532.  
1.3 A central aim of this practice is to provide information required for characterizing the uncertainty of concentration estimates from samples taken by candidate samplers. For this purpose, sampling accuracy data from the performance tests given here can be combined with information as to analytical and sampling pump uncertainty obtained externally. The practice applies principles of ISO GUM, expanded to cover situations common in occupational hygiene measurement, where the measurand varies markedly in both time and space. A general approach (8) for dealing with this situation relates to the theory of tolerance intervals and may be summarized as follows: Sampling/analytical methods undergo extensive evaluations and are subsequently applied without re-evaluation at each measurement, while taking precautio...

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Publication Date
31-Mar-2012
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
´1
Designation: D6061 − 01 (Reapproved 2012)
Standard Practice for
Evaluating the Performance of Respirable Aerosol
Samplers
This standard is issued under the fixed designation D6061; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—Reapproved with editorial changes in April 2012.
1. Scope given here can be combined with information as to analytical
and sampling pump uncertainty obtained externally. The prac-
1.1 This practice covers the evaluation of the performance
tice applies principles of ISO GUM, expanded to cover
of personal samplers of non-fibrous respirable aerosol. The
situations common in occupational hygiene measurement,
samplers are assessed relative to a specific respirable sampling
where the measurand varies markedly in both time and space.
convention. The convention is one of several that identify
Ageneral approach (8) for dealing with this situation relates to
specific particle size fractions for assessing health effects of
the theory of tolerance intervals and may be summarized as
airborne particles. When a health effects assessment has been
follows: Sampling/analytical methods undergo extensive
basedonaspecificconventionitisappropriatetousethatsame
evaluationsandaresubsequentlyappliedwithoutre-evaluation
convention for setting permissible exposure limits in the
at each measurement, while taking precautions (for example,
workplace and ambient environment and for monitoring com-
through a quality assurance program) that the method remains
pliance.Theconventions,whichdefineinhalable,thoracic,and
stable. Measurement uncertainty is then characterized by
respirable aerosol sampler ideals, have now been adopted by
specifying the evaluation confidence (for example, 95%) that
the International Standards Organization (ISO7708), the Co-
confidence intervals determined by measurements bracket
mité Européen de Normalisation (CEN Standard EN 481), and
measurand values at better than a given rate (for example,
theAmerican Conference of Governmental Industrial Hygien-
2 95%). Moreover, the systematic difference between candidate
ists (ACGIH, Ref (1)), developed (2) in part from health-
and idealized aerosol samplers can be expressed as a relative
effectsstudiesreviewedinRef (3)andinpartasacompromise
bias, which has proven to be a useful concept and is included
between definitions proposed in Refs (3,4).
in the specification of accuracy (3.2.9 – 3.2.10).
1.2 This practice is complementary to Test Method D4532,
3 1.4 Units of the International System of Units (SI) are used
which specifies a particular instrument, the 10-mm cyclone.
throughout this practice and should be regarded as standard.
The sampler evaluation procedures presented in this practice
1.5 This standard does not purport to address all of the
have been applied in the testing of the 10-mm cyclone as well
3,4
safety concerns, if any, associated with its use. It is the
as the Higgins-Dewell cyclone. Details on the evaluation
responsibility of the user of this standard to establish appro-
have been published (5-7) and can be incorporated into
priate safety and health practices and determine the applica-
revisions of Test Method D4532.
bility of regulatory limitations prior to use.
1.3 A central aim of this practice is to provide information
required for characterizing the uncertainty of concentration
2. Referenced Documents
estimates from samples taken by candidate samplers. For this
2.1 ASTM Standards:
purpose, sampling accuracy data from the performance tests
D1356Terminology Relating to Sampling and Analysis of
Atmospheres
ThispracticeisunderthejurisdictionofASTMCommitteeD22onAirQuality
D4532Test Method for Respirable Dust in Workplace At-
and is the direct responsibility of Subcommittee D22.04 on WorkplaceAir Quality.
mospheres Using Cyclone Samplers
Current edition approved April 1, 2012. Published July 2012. Originally
ε1
D6062GuideforPersonalSamplersofHealth-RelatedAero-
approved in 1996. Last previous edition approved in 2007 as D6061–01 (2007) .
DOI: 10.1520/D6061-01R12E01.
sol Fractions
The boldface numbers in parentheses refer to a list of references at the end of
this practice.
If you are aware of alternative suppliers, please provide this information to
ASTMHeadquarters.Yourcommentswillreceivecarefulconsiderationatameeting For referenced ASTM standards, visit the ASTM website, www.astm.org, or
of the responsible technical committee, which you may attend. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
The sole source of supply of the Higgins-Dewell cyclone known to the Standards volume information, refer to the standard’s Document Summary page on
committee at this time is BGI Inc., 58 Guinan Street, Waltham, MA 02154. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
D6061 − 01 (2012)
D6552Practice for Controlling and Characterizing Errors in
Weighing Collected Aerosols
2.2 International Standards:
ISO7708Air Quality—Particle Size Fraction Definitions
for Health-Related Sampling, Brussels, 1993
ISOGUM Guide to the Expression of Uncertainty in
Measurement, Brussels, 1993
CENEN 481Standard on Workplace Atmospheres. Size
Fraction Definitions for the Measurement of Airborne
Particles in the Workplace, Brussels, 1993
CENEN 1232Standard on Workplace Atmospheres. Re-
quirementsandTestMethodsforPumpsusedforPersonal
Sampling of ChemicalAgents in theWorkplace, Brussels,
CENEN 13205Workplace Atmospheres- Assessment of
FIG. 1 Respirable Aerosol Collection Efficiencies
Performance of Instruments for Measurement ofAirborne
Particle Concentrations, 2001
2.3 NIOSH Standards:
dust as promulgated by NIOSH (Criteria for a Recommended
NIOSHManual ofAnalytical Methods, 4thed., Eller, P. M.,
Standard, Occupational Exposure to Respirable Coal Mine
ed.: Dept. of Health and Human Services, 1994
Dust) and also forms the basis of the NIOSH sampling method
Criteria for a Recommended Standard, Occupational Expo-
for particulates not otherwise regulated, respirable (NIOSH
sure to Respirable Coal Mine Dust, NIOSH, 1995
Manual of Analytical Methods).
-1 -1
3.2.3 size-distribution C dC/dD (µm )—of a given air-
3. Terminology
borne aerosol, the mass concentration of aerosol per unit
3.1 Definitions:
aerodynamic diameter range per total concentration C.
3.1.1 For definitions of terms used in this practice, refer to
3.2.3.1 lognormal size distribution—an idealized distribu-
Terminology D1356 and ISOGUM.
tion characterized by two parameters: the geometric standard
3.1.2 Aerosol fraction sampling conventions have been
deviation (GSD) and mass median diameter (MMD). The
presented in Performance Specifications D6062. The relevant
distribution is given explicitly as follows:
definitions are repeated here for convenience.
1 1
3.2 Definitions of Terms Specific to This Standard:
21 2 2
C dC/dD 5 exp 2 ln@D/MMD# /ln@GSD#
F G
3.2.1 aerodynamic diameter, D (µm)—the diameter of a
=2π Dln GSD
@ #
sphere of density, 10 kg/m, with the same stopping time as a
(2)
particle of interest.
where C is the total mass concentration.
3.2.2 respirable sampling convention, E —defined explic-
R 3
3.2.4 conventional respirable concentration c (mg/m )—
R
itly at aerodynamic diameter D (µm) as a fraction of total
the concentration measured by a conventional (that is, ideal)
airborneaerosolintermsofthecumulativenormalfunction (9)
respirable sampler and given in terms of the size distribution
Φ as follows:
dC/dD as follows:
E 5 0.50 ~11exp@20.06 D#! Φ @ln@D /D#/σ # (1)
R R R
`
c 5 dD E dC/dD (3)
*
R R
where the indicated constants are D =4.25 µm and
R
3.2.4.1 Discussion—Note that samples are often taken over
σ =ln[1.5].
R
an extended time period (for example, 8 h), so that dC/dD of
3.2.2.1 Discussion—The respirable sampling convention,
Eq. 3 represents a time-averaged, rather than instantaneous,
together with earlier definitions, is shown in Fig. 1. This
size-distribution.
convention has been adopted by the International Standards
3.2.5 sampler number s = 1, ., S— a number identifying a
Organization (ISO7708), the Comité Européen de Normalisa-
particular sampler under evaluation.
tion (CEN Standard EN 481), and theAmerican Conference of
Governmental and Industrial Hygienists (ACGIH, Ref (1)).
3.2.6 sampling effıciency E (D, Q)—the modeled sampling
s
The definition of respirable aerosol is the basis for the
efficiency of sampler s as a function of aerodynamic diameter
recommended exposure level (REL) of respirable coal mine
D and flow rate Q (9.1).
3.2.6.1 model parameters θ , where p = 1, ., P (for
p
example, 4)—parameters that specify the function E (D, Q).
s
Available from International Organization for Standardization, Caisse Postale
3.2.7 mean sampled concentration c —the concentration
s
56, CH-1211, Geneva 20, Switzerland.
that sampler s would give, averaged over sampling pump and
Available from CEN Central Secretariat: rue de Stassart 36, B-1050 Brussels,
Belgium.
analytical fluctuations, in sampling aerosol of size-distribution
Available from Superintendent of Documents, U.S. Government Printing -1
C dC/dD is given as follows:
Office, Stock No. 917-011-00000-1, Washington DC 20402.
`
Available from NIOSH Publications, 4676 Columbia Parkway, Cincinnati, OH
c 5 * dD E dC/dD (4)
s s
45226. 0
´1
D6061 − 01 (2012)
3.2.8 mean concentration c—the population mean of c . GSD—geometric standard deviation of a lognormal aerosol
s
size distribution.
3.2.9 uncertainty components:
MMD—mass median diameter of a lognormal aerosol size
3.2.9.1 analytical relative standard deviation RSD —
analytical
distribution.
the standard deviation relative to the true respirable concen-
MSE —mean square element for sampler in application (see
c
tration c associated with mass analysis, for example, the
R
10.4).
weighing of filters, analysis of α-quartz, and so forth.
MSE—mean square element for evaluation data (see A1.5).
3.2.9.2 pump-induced relative standard deviation
n—number of replicate measurements.
RSD —the intra-sampler standard deviation relative to the
pump
P—number of sampling efficiency parameters.
respirable concentration c associated with both drift and
R
RSD—relative standard deviation (relative to concentration
variability in the setting of the sampling pump.
c as estimated by an ideal sampler following the respirable
R
3.2.9.3 inter-sampler relative standard deviation RSD —
inter
sampling convention).
the inter-sampler standard deviation (varying sampler s) rela-
RSD —relativestandarddeviationcomponentcharac-
tive to the respirable concentration c and taken as primarily analytical
R
terizing analytical random variation.
associated with physical variations in sampler dimensions.
RSD —relative standard deviation component character-
eval
3.2.10 mean relative bias ∆—of measurement c relative to
izing uncertainty from the evaluation experiment itself (Annex
the conventional respirable concentration c , defined as fol-
R
Annex A1).
lows:
RSD —relative standard deviation component character-
inter
∆[~c 2 c !/c (5)
R R
izing random inter-sampler variation.
RSD —relative standard deviation component character-
3.2.11 symmetric-range accuracy A—the fractional range,
pump
symmetric about the conventional concentration c , within izing the effect of random sampling pump variation.
R
s—sampler number.
which95%ofsamplermeasurementsaretobefound(8,10-13
and the NIOSH Manual of Analytical Methods). S—number of samplers evaluated.
3.2.12 flow rate Q (L/min)—the average flow rate of air t—sampling time (for example, 8h).
U—expanded uncertainty.
sampled by a given sampler over the duration of the sampling
period. u —combined uncertainty.
c
v (m/s)—wind speed.
3.2.13 flow number F—the number (for example, 4) of
∆—bias relative to an ideal sampler following the respirable
sampler flow rates Q tested.
sampling convention.
3.2.14 replication number n (for example, 4)— the number
ε —random variable contribution to evaluation experi-
eval s
of replicate measurements for evaluating a given sampler at
mental error in a concentration estimate.
specific flow rate and aerodynamic diameter.
ε —random variable contribution to inter-sampler error in a
s
3.3 Symbols and Abbreviations:
concentration estimate.
A—symmetric-range accuracy as defined in terms of bias and
θ—sampling efficiency model parameter.
precision (see 3.2.11).
σ —sampling efficiency model parameter.
—estimated accuracy A.
σ —evaluation experimental standard deviation in a con-
eval
centration estimate.
NOTE1—HatsasinArefertoestimates,bothinsamplerapplicationand
σ —inter-sampler standard deviation in a concentration
sampler evaluation.
inter
estimate.
A—95 % confidence limit on the symmetric-range
95 %
σ —respirable sampling convention parameter equal to
accuracy A. R
ln[1.5].
c(mg/m )—expected value of the sampler-averaged concen-
σ —weighing imprecision in mass collected on a filter.
tration estimates c . mass
s
Φ[x]—cumulative normal function given for argument x.
c (mg/m )—expectedvalue(averagedoversamplingpump
s
and analytical variations) of the concentration estimate from
4. Summary of Practice
sampler s.
cov —covariance matrix for sampler s and efficiency pa-
4.1 The sampling efficiency from D=0 to 10 µm and its
s ij
rameters θ and θ.
i j variability are measured in calm air (<0.5 m/s) for several
c (mg/m ) —concentration measured by a conventional
candidate samplers operated at a variety of flow rates. This
R
(that is, ideal) respirable sampler.
information is then used to compute concentration estimates
D (µm)—aerosol aerodynamic diameter.
expected in sampling representative lognormal aerosol size
D —sampling efficiency model parameter.
distributions. Random variations (10.2) as well as systematic
D (µm)—respirablesamplingconventionparameterequalto
deviation (10.1) are specified relative to a conventional sam-
R
4.25 µm in the case of healthy adults, or 2.5 µm for the sick or
pler. Overall performance in calm air can then be assessed by
infirm or children.
computing a confidence limit A on the symmetric-range
95 %
E—sampling convention in general.
accuracy (3.2.11), accounting for uncertainty in the evaluation
E —respirable sampling convention. experiment, given estimated bias and imprecision at each
R
E —sampling efficiency of sampler s.
lognormal aerosol size distribution of interest. The symmetric-
s
F—number of flow rates evaluated. range accuracy confidence limit A provides conservative
95 %
...

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