Standard Practice for Evaluating the Performance of Diffusive Samplers

SIGNIFICANCE AND USE
Gas or vapor sampling is often accomplished by actively pumping air through a collection medium such as activated charcoal. Problems associated with a pump–inconvenience, inaccuracy, and expense–are inextricable from this type of sampling. The alternative covered by this practice is to use diffusion for moving the compound of interest onto the collection medium. This approach to sampling is attractive because of the convenience of use and low total monitoring cost.
However, previous studies have found significant problems with the accuracy of some samplers. Therefore, although diffusive samplers may provide a plethora of data, inaccuracies and misuse of diffusive samplers may yet affect research studies. Furthermore, worker protections may be based on faulty assumptions. The aim of this practice is to counter the uncertainties in diffusive sampling through achieving a broadly accepted set of performance tests and acceptance criteria for proving the efficacy of any given diffusive sampler intended for use.
SCOPE
1.1 This practice covers the evaluation of the performance of diffusive samplers of gases and vapors for use over sampling periods from 4 to 12 h and for wind speeds less than 0.5 m/s. Such sampling periods and wind speeds are the most common in the indoor workplace setting. This practice does not apply to static or area sampling in wind speeds less than 0.1 m/s, when diffusion outside the sampler may dominate needed convection from the ambient air to the vicinity of the sampler. Given a suitable exposure chamber, the practice can be extended to cover sampler use for other sampling periods and conditions. The aim is to provide a concise set of experiments for classifying samplers primarily in accordance with a single sampler accuracy figure. Accuracy is defined (3.2.1) in this standard so as to take into account both imprecision and uncorrected bias. Accuracy estimates refer to conditions of sampler use which are normally expected in a workplace setting. These conditions may be characterized by the temperature, atmospheric pressure, humidity, and ambient wind speed, none of which may be constant or accurately known when the sampler is used in the field. Futhermore, the accuracy accounts for the effects of diffusive loss of analyte on the estimation of time-weighted averages of concentrations which may not be constant in time. Aside from accuracy, the samplers are tested for compliance with the manufacturer's stated limits on capacity, possibly in the presence of interfering compounds.
1.2 This practice is an extension of previous research on diffusive samplers (1-14) as well as Practices D 4597, D 4598, D 4599, and MDHS 27. An essential advance here is the estimation of sampler accuracy under actual conditions of use. Futhermore, the costs of sampler evaluation are reduced.
1.3 Knowledge gained from similar analytes expedites sampler evaluation. For example, interpolation of data characterizing the sampling of analytes at separated points of a homologous series of compounds is recommended. At present the procedure of (9) is suggested. Following evaluation of a sampler in use at a single homologous series member according to the present practice, higher molecular weight members would receive partial validations considering sampling rate, capacity, analytical recovery, and interferences. The test for diffusive analyte loss can be omitted if the effect is found negligible for a given sampler or analyte series.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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.

General Information

Status
Historical
Publication Date
31-Mar-2008
Technical Committee
Current Stage
Ref Project

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Standards Content (Sample)

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
Designation: D6246 − 08
StandardPractice for
1
Evaluating the Performance of Diffusive Samplers
This standard is issued under the fixed designation D6246; 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 homologous series of compounds is recommended.At present
the procedure of (9) is suggested. Following evaluation of a
1.1 This practice covers the evaluation of the performance
sampler in use at a single homologous series member accord-
ofdiffusivesamplersofgasesandvaporsforuseoversampling
ing to the present practice, higher molecular weight members
periods from 4 to 12 h and for wind speeds less than 0.5 m/s.
would receive partial validations considering sampling rate,
Such sampling periods and wind speeds are the most common
capacity, analytical recovery, and interferences. The test for
intheindoorworkplacesetting.Thispracticedoesnotapplyto
diffusive analyte loss can be omitted if the effect is found
static or area sampling in wind speeds less than 0.1 m/s, when
negligible for a given sampler or analyte series.
diffusion outsidethesamplermaydominateneededconvection
from the ambient air to the vicinity of the sampler. Given a 1.4 The values stated in SI units are to be regarded as
suitable exposure chamber, the practice can be extended to
standard. No other units of measurement are included in this
cover sampler use for other sampling periods and conditions. standard.
The aim is to provide a concise set of experiments for
1.5 This standard does not purport to address all of the
classifying samplers primarily in accordance with a single
safety concerns, if any, associated with its use. It is the
sampler accuracy figure. Accuracy is defined (3.2.1) in this
responsibility of the user of this standard to establish appro-
standard so as to take into account both imprecision and
priate safety and health practices and determine the applica-
uncorrected bias. Accuracy estimates refer to conditions of
bility of regulatory limitations prior to use.
sampler use which are normally expected in a workplace
setting. These conditions may be characterized by the
2. Referenced Documents
temperature, atmospheric pressure, humidity, and ambient
3
2.1 ASTM Standards:
wind speed, none of which may be constant or accurately
D1356Terminology Relating to Sampling and Analysis of
known when the sampler is used in the field. Futhermore, the
Atmospheres
accuracyaccountsfortheeffectsofdiffusivelossofanalyteon
D4597Practice for Sampling Workplace Atmospheres to
the estimation of time-weighted averages of concentrations
Collect Gases or Vapors with Solid Sorbent Diffusive
which may not be constant in time. Aside from accuracy, the
Samplers
samplers are tested for compliance with the manufacturer’s
D4598Practice for Sampling Workplace Atmospheres to
statedlimitsoncapacity,possiblyinthepresenceofinterfering
Collect Gases or Vapors with Liquid Sorbent Diffusional
compounds.
4
Samplers (Withdrawn 1995)
1.2 This practice is an extension of previous research on
D4599Practice for Measuring the Concentration of Toxic
2
diffusive samplers (1-14) as well as Practices D4597, D4598,
Gases or Vapors Using Length-of-Stain Dosimeters
D4599, and MDHS 27. An essential advance here is the
2.2 International Standards:
estimation of sampler accuracy under actual conditions of use.
CEN EN 838European Standard, Workplace atmospheres -
Futhermore, the costs of sampler evaluation are reduced.
Diffusive samplers for the determination of gases or
1.3 Knowledgegainedfromsimilaranalytesexpeditessam-
5
vapours - Requirements and test methods
pler evaluation. For example, interpolation of data character-
MDHS 27Protocol for assessing the performance of a
izing the sampling of analytes at separated points of a
1 3
This practice is under the jurisdiction of ASTM Committee D22 on Air For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Qualityand is the direct responsibility of Subcommittee D22.04 on Workplace Air contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Quality. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved April 1, 2008. Published May 2008. Originally the ASTM website.
4
approved in 1998. Last previous edition approved in 2002 as D6246-02. DOI: The last approved version of this historical standard is referenced on
10.1520/D6246-08. www.astm.org.
2 5
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof Available from CEN Central Secretariat, rue de Stassart 36, B-1050 Brussels,
this standard. Belgium.
Copyright © ASTM International,
...

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:D6246–02 Designation: D 6246 – 08
Standard Practice for
1
Evaluating the Performance of Diffusive Samplers
This standard is issued under the fixed designation D 6246; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This practice covers the evaluation of the performance of diffusive samplers of gases and vapors for use over sampling
periods from 4 to 12 h and for wind speeds less than 0.5 m/s. Such sampling periods and wind speeds are the most common in
the indoor workplace setting. This practice does not apply to static or area sampling in wind speeds less than 0.1 m/s, when
diffusion outsidethesamplermaydominateneededconvectionfromtheambientairtothevicinityofthesampler.Givenasuitable
exposure chamber, the practice can be extended to cover sampler use for other sampling periods and conditions. The aim is to
provide a concise set of experiments for classifying samplers primarily in accordance with a single sampler accuracy figure.
Accuracy is defined (3.2.1) in this standard so as to take into account both imprecision and uncorrected bias.Accuracy estimates
refer to conditions of sampler use which are normally expected in a workplace setting. These conditions may be characterized by
the temperature, atmospheric pressure, humidity, and ambient wind speed, none of which may be constant or accurately known
whenthesamplerisusedinthefield.Futhermore,theaccuracyaccountsfortheeffectsofdiffusivelossofanalyteontheestimation
of time-weighted averages of concentrations which may not be constant in time.Aside from accuracy, the samplers are tested for
compliance with the manufacturer’s stated limits on capacity, possibly in the presence of interfering compounds.
2
1.2 Thispracticeisanextensionofpreviousresearchondiffusivesamplers(1-14) aswellasPracticesD4597,D4598,D4599,
and MDHS 27. An essential advance here is the estimation of sampler accuracy under actual conditions of use. Futhermore, the
costs of sampler evaluation are reduced.
1.3 Knowledgegainedfromsimilaranalytesexpeditessamplerevaluation.Forexample,interpolationofdatacharacterizingthe
sampling of analytes at separated points of a homologous series of compounds is recommended. At present the procedure of (9)
is suggested. Following evaluation of a sampler in use at a single homologous series member according to the present practice,
higher molecular weight members would receive partial validations considering sampling rate, capacity, analytical recovery, and
interferences.Thetestfordiffusiveanalytelosscanbeomittediftheeffectisfoundnegligibleforagivensampleroranalyteseries.
1.4Units of the International System of Units (SI) are used throughout this guide and should be regarded as standard.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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
3
2.1 ASTM Standards:
D 1356 Terminology Relating to Sampling and Analysis of Atmospheres
D 4597 Practice for Sampling Workplace Atmospheres to Collect Organic Gases or Vapors with Activated CharcoalSolid
Sorbent Diffusive Samplers
4
D 4598 Practice for Sampling WorkplaceAtmospheres to Collect Gases or Vapors with Liquid Sorbent Diffusional Samplers
D 4599 Practice for Measuring the Concentration of Toxic Gases or Vapors Using Length-of-Stain Dosimeters
2.2 International Standards:
CEN EN 838 European Standard, Workplace atmospheres - Diffusive samplers for the determination of gases or vapours -
Requirements and test methods
1
This practice is under the jurisdiction ofASTM Committee D22 on Sampling andAnalysis ofAtmospheres and is the direct responsibility of Subcommittee D22.04 on
Workplace Atmospheres.
Current edition approved October 10, 2002. Published December 2002. Originally published as D6246–98. Last previous edition D6246–01.
1
This practice is under the jurisdiction of ASTM Committee D22 on Air Quality and is the direct responsibility of Subcommittee D22.04 on Workplace Air Quality .
Current edition approved April 1, 2008. Published M
...

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