ASTM D6061-01(2007)e1
(Practice)Standard Practice for Evaluating the Performance of Respirable Aerosol Samplers
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:
5.1.1 The conventions have a recognized tie to health effects and can easily be adjusted to accommodate new findings.
5.1.2 Performance criteria permit instrument designers to seek practical sampler improvements.
5.1.3 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 DiscussionIn 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 (Technical Report ISO TR 7708), the Comit Europen 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 complimentary to Test Method D 4532, 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 recently published (5-7) and can be incorporated into revisions of Test Method D 4532.
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 ...
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Designation:D6061–01 (Reapproved 2007)
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.
´ NOTE—Editorially removed the Metric designation from Specification D6062 in April 2007.
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 (Technical Report
confidence intervals determined by measurements bracket
ISOTR 7708), the Comité Européen de Normalisation (CEN
measurand values at better than a given rate (for example,
Standard EN 481), and the American Conference of Govern-
95%). Moreover, the systematic difference between candidate
mentalIndustrialHygienists(ACGIH,Ref (1)), developed (2)
and idealized aerosol samplers can be expressed as a relative
in part from health-effects studies reviewed in Ref (3) and in
bias, which has proven to be a useful concept and is included
part as a compromise between definitions proposed in Refs
in the specification of accuracy (3.2.9-3.2.10).
(3,4).
1.4 Units of the International System of Units (SI) are used
1.2 This practice is complimentary to Test Method D4532,
3 throughout this practice and should be regarded as standard.
which specifies a particular instrument, the 10-mm cyclone.
1.5 This standard does not purport to address all of the
The sampler evaluation procedures presented in this practice
safety concerns, if any, associated with its use. It is the
have been applied in the testing of the 10-mm cyclone as well
3,4
responsibility of the user of this standard to establish appro-
as the Higgins-Dewell cyclone. Details on the evaluation
priate safety and health practices and determine the applica-
have been recently published (5-7) and can be incorporated
bility of regulatory limitations prior to use.
into revisions of Test Method D4532.
1.3 A central aim of this practice is to provide information
2. Referenced Documents
required for characterizing the uncertainty of concentration
2.1 ASTM Standards:
estimates from samples taken by candidate samplers. For this
D1356 Terminology Relating to Sampling and Analysis of
purpose, sampling accuracy data from the performance tests
Atmospheres
D4532 Test Method for Respirable Dust in Workplace
Atmospheres
ThispracticeisunderthejurisdictionofASTMCommitteeD22onAirQuality
andisthedirectresponsibilityofSubcommitteeD22.04onWorkplaceAtmospheres. D6062 Guide for Personal Samplers of Health-Related
Current edition approved April 1, 2007. Published June 2007. Originally
Aerosol Fractions
approved in 1996. Last previous edition approved in 2001 as D6061-01. DOI:
D6552 PracticeforControllingandCharacterizingErrorsin
10.1520/D6061-01R07E01.
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.
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D6061–01 (2007)
Weighing Collected Aerosols
2.2 International Standards:
ISOTR 7708 Technical Report on Air Quality—Particle
Size Fraction Definitions for Health-Related Sampling,
Brussels, 1993
ISOGUM Guide to the Expression of Uncertainty in Mea-
surement, Brussels, 1993
CENEN 481 Standard on Workplace Atmospheres. Size
Fraction Definitions for the Measurement of Airborne
Particles in the Workplace, Brussels, 1993
CENEN 1232 Standard on Workplace Atmospheres. Re-
quirementsandTestMethodsforPumpsusedforPersonal
Sampling of ChemicalAgents in theWorkplace, Brussels,
CENEN 13205 Workplace Atmospheres- Assessment of
FIG. 1 Respirable Aerosol Collection Efficiencies
Performance of Instruments for Measurement ofAirborne
Particle Concentrations, 2001
2.3 NIOSH Standards:
for a Recommended Standard, Occupational Exposure to
NIOSHManualofAnalyticalMethods,4th ed.,Eller,P.M.,
Respirable Coal Mine Dust) and also forms the basis of the
ed.: Dept. of Health and Human Services, 1994
NIOSH sampling method for particulates not otherwise regu-
Criteria for a Recommended Standard, Occupational Expo-
lated, respirable (NIOSH Manual of Analytical Methods).
sure to Respirable Coal Mine Dust, NIOSH, 1995
-1 -1
3.2.3 size-distribution C dC/dD (µm )—of a given air-
borne aerosol, the mass concentration of aerosol per unit
3. Terminology
aerodynamic diameter range per total concentration C.
3.1 Definitions:
3.2.3.1 lognormal size distribution—an idealized distribu-
3.1.1 For definitions of terms used in this practice, refer to
tion characterized by two parameters: the geometric standard
Terminology D1356 and ISOGUM.
deviation (GSD) and mass median diameter (MMD). The
3.1.2 Aerosol fraction sampling conventions have been
distribution is given explicitly as follows:
presented in Performance Specifications D6062. The relevant
1 1
definitions are repeated here for convenience.
21 2 2
C dC/dD 5 exp 2 ln@D/MMD] /ln@GSD] #
F
2p Dln@GSD]
3.2 Definitions of Terms Specific to This Standard: =
(2)
3.2.1 aerodynamic diameter, D (µm)—the diameter of a
sphere of density, 10 kg/m, with the same stopping time as a
where C is the total mass concentration.
particle of interest.
3.2.4 conventional respirable concentration c (mg/m )—
R
3.2.2 respirable sampling convention, E —defined explic-
the concentration measured by a conventional (that is, ideal)
R
itly at aerodynamic diameter D (µm) as a fraction of total
respirable sampler and given in terms of the size distribution
airborneaerosolintermsofthecumulativenormalfunction (9)
dC/dD as follows:
F as follows:
`
c 5 dD E dC/ dD (3)
R * R
E 50.50 ~1 1exp@20.06 D]! F[ln@D /D]/s # (1)
R R R
3.2.4.1 Discussion—Note that samples are often taken over
where the indicated constants are D = 4.25 µm and
R
an extended time period (for example, 8 h), so that dC/dD of
s =ln[1.5].
R
Eq. 3 represents a time-averaged, rather than instantaneous,
3.2.2.1 Discussion—The respirable sampling convention,
size-distribution.
together with earlier definitions, is shown in Fig. 1. This
3.2.5 sampler number s = 1, ., S— a number identifying a
convention has been adopted by the International Standards
particular sampler under evaluation.
Organization (Technical Report ISOTR 7708), the Comité
3.2.6 sampling effıciency E (D, Q)—the modeled sampling
Européen de Normalisation (CEN Standard EN 481), and the s
efficiency of sampler s as a function of aerodynamic diameter
American Conference of Governmental and Industrial Hygien-
D and flow rate Q (9.1).
ists (ACGIH, Ref (1)). The definition of respirable aerosol is
3.2.6.1 model parameters u , where p = 1, ., P (for ex-
the basis for the recommended exposure level (REL) of
p
ample, 4)—parameters that specify the function E (D, Q).
respirable coal mine dust as promulgated by NIOSH (Criteria s
3.2.7 mean sampled concentration c —the concentration
s
that sampler s would give, averaged over sampling pump and
Available from International Organization for Standardization, Caisse Postale
analytical fluctuations, in sampling aerosol of size-distribution
56, CH-1211, Geneva 20, Switzerland. -1
C dC/dD is given as follows:
Available from CEN Central Secretariat: rue de Stassart 36, B-1050 Brussels,
`
Belgium.
c 5 dD E dC/ dD (4)
s * s
Available from Superintendent of Documents, U.S. Government Printing
Office, Stock No. 917-011-00000-1, Washington DC 20402.
3.2.8 mean concentration c—the population mean of c .
Available from NIOSH Publications, 4676 Columbia Parkway, Cincinnati, OH s
45226. 3.2.9 uncertainty components:
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D6061–01 (2007)
3.2.9.1 analytical relative standard deviation RSD — MMD—mass median diameter of a lognormal aerosol size
analytical
the standard deviation relative to the true respirable concen- distribution.
tration c associated with mass analysis, for example, the MSE —mean square element for sampler in application (see
R c
weighing of filters, analysis of a-quartz, and so forth. 10.4).
3.2.9.2 pump-induced relative standard deviation MSE—mean square element for evaluation data (see A1.5).
RSD —the intra-sampler standard deviation relative to the n—number of replicate measurements.
pump
respirable concentration c associated with both drift and P—number of sampling efficiency parameters.
R
variability in the setting of the sampling pump.
RSD—relative standard deviation (relative to concentration
c as estimated by an ideal sampler following the respirable
3.2.9.3 inter-sampler relative standard deviation RSD —
R
inter
the inter-sampler standard deviation (varying sampler s) rela- sampling convention).
tive to the respirable concentration c and taken as primarily RSD —relativestandarddeviationcomponentcharac-
R analytical
associated with physical variations in sampler dimensions. terizing analytical random variation.
RSD —relative standard deviation component character-
3.2.10 mean relative bias D—of measurement c relative to
eval
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
D[~c2c !/c (5)
R R
izing random inter-sampler variation.
3.2.11 symmetric-range accuracy A—the fractional range,
RSD —relative standard deviation component character-
pump
symmetric about the conventional concentration c , within
R
izing the effect of random sampling pump variation.
which95%ofsamplermeasurementsaretobefound(8,10-13
s—sampler number.
and the NIOSHManual 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).
sampled by a given sampler over the duration of the sampling
U—expanded uncertainty.
period.
u —combined uncertainty.
c
3.2.13 flow number F—the number (for example, 4) of
v (m/s)—wind speed.
sampler flow rates Q tested.
D—bias relative to an ideal sampler following the respirable
3.2.14 replication number n (for example, 4)— the number
sampling convention.
of replicate measurements for evaluating a given sampler at
´ —random variable contribution to evaluation experi-
eval s
specific flow rate and aerodynamic diameter.
mental error in a concentration estimate.
3.3 Symbols and Abbreviations:
´ —random variable contribution to inter-sampler error in a
s
A—symmetric-range accuracy as defined in terms of bias
concentration estimate.
and precision (see 3.2.11).
u—sampling efficiency model parameter.
—estimated accuracy A.
s —sampling efficiency model parameter.
s —evaluation experimental standard deviation in a con-
eval
NOTE 1—Hats as in A refer to estimates, both in sampler application
centration estimate.
and sampler evaluation.
s —inter-sampler standard deviation in a concentration
inter
A—95 % confidence limit on the symmetric-range
95 %
estimate.
accuracy A.
s —respirable sampling convention parameter equal to
3 R
c(mg/m )—expected value of the sampler-averaged concen-
ln[1.5].
tration estimates c .
s
s —weighing imprecision in mass collected on a filter.
mass
c (mg/m )—expected value (averaged over sampling pump
s
F[x]—cumulative normal function given for argument x.
and analytical variations) of the concentration estimate from
sampler s.
4. Summary of Practice
cov —covariance matrix for sampler s and efficiency pa-
s ij
4.1 The sampling efficiency from D=0 to 10 µm and its
rameters u and u.
i j
variability are measured in calm air (<0.5 m/s) for several
c (mg/m )—concentrationmeasuredbyaconventional(that
R
candidate samplers operated at a variety of flow rates. This
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
R
deviation (10.1) are specified relative to a conventional sam-
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.
R experiment, given estimated bias and imprecision at each
E —sampling efficiency of sampler s.
s lognormal aerosol size distribution of interest. The symmetric-
F—number of flow rates evaluated.
range accuracy confidence limit A provides conservative
95 %
GSD—geom
...
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