ASTM D6552-06
(Practice)Standard Practice for Controlling and Characterizing Errors in Weighing Collected Aerosols
Standard Practice for Controlling and Characterizing Errors in Weighing Collected Aerosols
SIGNIFICANCE AND USE
The weighing of collected aerosol is one of the most common and purportedly simple analytical procedures in both occupational and environmental atmospheric monitoring (for example, Test Method D 4532 or D 4096). Problems with measurement accuracy occur when the amount of material collected is small, owing both to balance inaccuracy and variation in the weight of that part of the sampling medium that is weighed along with the sample. The procedures presented here for controlling and documenting such analytical errors will help provide the accuracy required for making well-founded decisions in identifying, characterizing, and controlling hazardous conditions.
Recommendations are given as to materials to be used. Means of controlling or correcting errors arising from instability are provided. Recommendations as to the weighing procedure are given. Finally, a method evaluation procedure for estimating weighing errors is described.
Recommendations are also provided for the reporting of weights relative to LOD (see 3.2.6) and LOQ (see 3.2.7). The quantities, LOD and LOQ, are computed as a result of the method evaluation.
SCOPE
1.1 Assessment of airborne aerosol hazards in the occupational setting entails sampling onto a collection medium followed by analysis of the collected material. The result is generally an estimated concentration of a possibly hazardous material in the air. The uncertainty in such estimates depends on several factors, one of which relates to the specific type of analysis employed. The most commonly applied method for analysis of aerosols is the weighing of the sampled material. Gravimetric analysis, though apparently simple, is subject to errors from instability in the mass of the sampling medium and other elements that must be weighed. An example is provided by aerosol samplers designed to collect particles so as to agree with the inhalable aerosol sampling convention (see ISO TR 7708, Guide D 6062M, and EN 481). For some sampler types, filter and cassette are weighed together to make estimates. Therefore, if the cassette, for example, absorbs or loses water between the weighings required for a concentration estimation, then errors may arise. This practice covers such potential errors and provides solutions for their minimization.
1.2 The values given in SI units are to be regarded as standard.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:D6552–06
Standard Practice for
Controlling and Characterizing Errors in Weighing Collected
1
Aerosols
This standard is issued under the fixed designation D6552; 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.
1. Scope D4096 Test Method for Determination of Total Suspended
Particulate Matter in theAtmosphere (High−Volume Sam-
1.1 Assessment of airborne aerosol hazards in the occupa-
pler Method)
tional setting entails sampling onto a collection medium
D4532 Test Method for Respirable Dust in Workplace
followed by analysis of the collected material. The result is
Atmospheres Using Cyclone Samplers
generally an estimated concentration of a possibly hazardous
D6062 Guide for Personal Samplers of Health-Related
material in the air. The uncertainty in such estimates depends
Aerosol Fractions
on several factors, one of which relates to the specific type of
3
2.2 International Standards:
analysis employed. The most commonly applied method for
EN481 WorkplaceAtmospheres—SizeFractionDefinitions
analysis of aerosols is the weighing of the sampled material.
for Measurement of Airborne Particles in the Workplace
Gravimetric analysis, though apparently simple, is subject to
EN 482 Workplace Atmospheres—General Requirements
errorsfrominstabilityinthemassofthesamplingmediumand
for Performance of Procedures for the Measurement of
other elements that must be weighed.An example is provided
Chemical Agents
by aerosol samplers designed to collect particles so as to agree
prEN 13205 Workplace Atmospheres—Assessment of Per-
with the inhalable aerosol sampling convention (see ISO TR
formance of Instruments for Measurement of Airborne
7708, Guide D6062, and EN481). For some sampler types,
Particle Concentrations
filter and cassette are weighed together to make estimates.
4
2.3 ISO Standards:
Therefore, if the cassette, for example, absorbs or loses water
ISO TR 7708 Air Quality—Particle Size Fraction Defini-
betweentheweighingsrequiredforaconcentrationestimation,
tions for Health-related Sampling
thenerrorsmayarise.Thispracticecoverssuchpotentialerrors
ISO GUM Guide to the Expression of Uncertainty in
and provides solutions for their minimization.
Measurement (1993)
1.2 The values given in SI units are to be regarded as
ISO 20988 Air Quality—Guidelines for Estimating Mea-
standard.
surement Uncertainty
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3. Terminology
responsibility of the user of this standard to establish appro-
3.1 Definitions:
priate safety and health practices and determine the applica-
3.1.1 For definitions of terms used in this practice, refer to
bility of regulatory limitations prior to use.
Terminology D1356.
2. Referenced Documents 3.2 Definitions of Terms Specific to This Standard:
2 3.2.1 blank substrate—a collection medium or substrate
2.1 ASTM Standards:
coming from the same batch as the sampling medium, but
D1356 Terminology Relating to Sampling and Analysis of
unexposed.
Atmospheres
3.2.2 equilibration time—For the purposes of this practice,
a time constant (seconds) characterizing an approximate expo-
1
ThispracticeisunderthejurisdictionofASTMCommitteeD22onAirQuality
nentiallydampedapproachofthemassofanaerosolcollection
andisthedirectresponsibilityofSubcommitteeD22.04onWorkplaceAtmospheres.
mediumtoaconstantvalue.Theconstantcanbedefinedasthe
Current edition approved April 1, 2006. Published May 2006. Originally
approved in 2000. Last previous edition approved in 2000 as D6552-00. DOI:
10.1520/D6552-06.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from CEN Central Secretariat: rue de Stassart 36, B-1050 Brussels,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Belgium.
4
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
---------------------- Page: 1 ----------------------
D6552–06
mean difference of the mass from equilibrium per mean mass
n = number of degrees of freedom in method
loss or gain rate as measured over a finite time interval.
evaluation
3.2.2.1 Discussion—There may be important instances in
F = cumulative normal function
2
x = chi-square random variable
which several time constants are required to describe the
2
x = chi-square quantile (that is, a fixed number
approach to equi
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:D6552–00 Designation:D6552–06
Standard Practice for
Controlling and Characterizing Errors in Weighing Collected
1
Aerosols
This standard is issued under the fixed designation D 6552; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 Assessment of airborne aerosol hazards in the occupational setting entails sampling onto a collection medium followed by
analysis of the collected material. The result is generally an estimated concentration of a possibly hazardous material in the air.
The accuracy ofuncertainty in such estimates depends on several factors, one of which relates to the specific type of analysis
employed. The most commonly applied method for analysis of aerosols is the weighing of the sampled material. Gravimetric
analysis, though apparently simple, is subject to errors from instability in the mass of the sampling medium and other elements
that must be weighed. An example is provided by aerosol samplers designed to collect particles so as to agree with the inhalable
aerosol sampling convention (see ISO TR 7708, Guide D 6062M, and EN 481). For some sampler types, filter and cassette are
weighed together to make estimates.Therefore, if the cassette, for example, absorbs or loses water between the weighings required
for a concentration estimation, then errors may arise. This practice covers such potential errors and provides solutions for their
minimization.
1.2 The values given in SI units are to be regarded as the standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
D 1356 Terminology Relating to Sampling and Analysis of Atmospheres
D 4096 Test Method for Determination of Total Suspended Particulate Matter in the Atmosphere (High-Volume Sampler
Method)
D 4532 Test Method for Respirable Dust in Workplace Atmospheres
2
D 6062M Guide for Personal Samplers of Health-Related Aerosol Fractions (Metric)
3
2.2 International Standards:
EN 481 Workplace Atmospheres—Size Fraction Definitions for Measurement of Airborne Particles in the Workplace
EN 482 Workplace Atmospheres—General Requirements for Performance of Procedures for the Measurement of Chemical
Agents
prEN 13205 Workplace Atmospheres—Assessment of Performance of Instruments for Measurement of Airborne Particle
Concentrations
4
2.3 ISO Standards:
ISO TR 7708Air Quality—Particle Size Fraction Definitions for Health-related Sampling Air Quality—Particle Size Fraction
Definitions for Health-related Sampling
ISO GUM Guide to the Expression of Uncertainty in Measurement (1993)
ISO 20988 Air Quality—Guidelines for Estimating Measurement Uncertainty
1
This test method practice is under the jurisdiction ofASTM Committee D22 on Sampling andAnalysis ofAtmospheres and is the direct responsibility of Subcommittee
on Air Quality and is the direct responsibility of Subcommittee D22.04 on Workplace Atmospheres .
Current edition approved May 10, 2000. Published July 2000.
Current edition approved April 1, 2006. Published May 2006. Originally approved in 2000. Last previous edition approved in 2000 as D 6552 - 00.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
, Vol 11.03.volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from CEN Central Secretariat: rue de Stassart 36, B-1050 Brussels, Belgium.
4 nd th
Available from American National Standards Institute, 11 W 42 Street, 13 Floor, New York, NY 10017.
4
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
---------------------- Page: 1 ----------------------
D6552–06
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this practice, refer to Terminology D 1356.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 blank substrate—a collection medium or substrate coming from the same bat
...
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