ASTM E908-98(2018)

Standard Practice for Calibrating Gaseous Reference Leaks

ABSTRACT
This practice establishes the standard procedures for calibrating leak artifacts of a specified gas, that may be used for determining the response of leak detectors, or in other situations where a known small flow of gas is required. The purpose of this practice is to establish calibration without reference to other calibrated leaks in as straightforward a manner as possible using the likeliest available equipment. The two types of leaks considered here are Type I, which is pressure to vacuum, and Type II, which is pressure to atmosphere. Three calibration methods are described under each type of reference leak, as follows: Method A—accumulation comparison using a known volume of tracer gas at specified conditions of temperature and pressure as a reference; Method B—accumulation comparison using a reference leak artifact calibrated using Method A; and Method C—direct measurement of leak rate by timing the movement (displacement) of a liquid slug, by the leak, in a capillary tube of known dimensions.
SCOPE
1.1 This practice covers procedures for calibrating leak artifacts of a specified gas, that may be used for determining the response of leak detectors, or in other situations where a known small flow of gas is required. The purpose of this practice is to establish calibration without reference to other calibrated leaks in as straightforward a manner as possible using the likeliest available equipment. While the uncertainties associated with these procedures will most likely be greater than those obtained via traceable calibration chains (on the order of 10 %), these procedures allow independent means of establishing or verifying the leakage rate from leak artifacts of questionable history, or when traceable leak artifacts are not available.  
1.2 Two types of leaks are considered:  
1.2.1 Type I—Pressure to vacuum.  
1.2.2 Type II—Pressure to atmosphere.  
1.3 Three calibration methods are described under each type of reference leak:  
1.3.1 Method A—Accumulation comparison, using a known volume of gas at specified conditions of temperature and pressure as a reference.  
1.3.2 Method B—Accumulation comparison, using a leak artifact calibrated using Method A.  
1.3.3 Method C—Displacement of a liquid slug, by the leak, in capillary tube of known dimensions.  
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Historical
• Publication Date: 31-May-2018
• ICS: 17.060 - Measurement of volume, mass, density, viscosity
• Technical Committee: E07 - Nondestructive Testing
• Drafting Committee: E07.08 - Leak Testing Method

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: E908 − 98 (Reapproved 2018)
Standard Practice for
1
Calibrating Gaseous Reference Leaks
This standard is issued under the fixed designation E908; 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 1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 This practice covers procedures for calibrating leak
ization established in the Decision on Principles for the
artifacts of a specified gas, that may be used for determining
Development of International Standards, Guides and Recom-
the response of leak detectors, or in other situations where a
mendations issued by the World Trade Organization Technical
known small flow of gas is required. The purpose of this
Barriers to Trade (TBT) Committee.
practice is to establish calibration without reference to other
calibrated leaks in as straightforward a manner as possible
2. Referenced Documents
using the likeliest available equipment.While the uncertainties
2
associated with these procedures will most likely be greater 2.1 ASTM Standards:
E425Definitions of Terms Relating to Leak Testing (With-
than those obtained via traceable calibration chains (on the
3
order of 10%), these procedures allow independent means of drawn 1991)
E427PracticeforTestingforLeaksUsingtheHalogenLeak
establishing or verifying the leakage rate from leak artifacts of
3
questionable history, or when traceable leak artifacts are not Detector Alkali-Ion Diode (Withdrawn 2013)
E479Guide for Preparation of a Leak Testing Specification
available.
3
(Withdrawn 2014)
1.2 Two types of leaks are considered:
F134Test Methods for Determining Hermeticity of Electron
1.2.1 Type I—Pressure to vacuum.
Devices with a Helium Mass Spectrometer Leak Detector
1.2.2 Type II—Pressure to atmosphere.
3
(Withdrawn 1996)
1.3 Threecalibrationmethodsaredescribedundereachtype
2.2 Other Documents:
of reference leak: 4
AVS 2.2-1968Method for Vacuum Leak Calibration
1.3.1 MethodA—Accumulation comparison, using a known
Recommended Practices for the Calibration and Use of
volume of gas at specified conditions of temperature and 5
Leaks
pressure as a reference.
1.3.2 Method B—Accumulation comparison, using a leak
3. Summary of Practice
artifact calibrated using Method A.
3.1 Method A—Accumulation comparison, using a known
1.3.3 MethodC—Displacementofaliquidslug,bytheleak,
volume of tracer gas:
in capillary tube of known dimensions.
3.1.1 This method uses a closed chamber of nonreactive
1.4 The values stated in inch-pound units are to be regarded
material having a means of removing all tracer gas and a
as standard. The values given in parentheses are mathematical
connection to the tracer sensor.
conversions to SI units that are provided for information only
3.1.2 A small, known quantity of tracer gas is discharged
and are not considered standard.
intothechamberandtheresponserecordedforaperiodoftime
inwhichitisanticipatedtheunknownleakwillrequiretoreach
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the the same concentration.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
1 3
This practice is under the jurisdiction of ASTM Committee E07 on Nonde- The last approved version of this historical standard is referenced on
structive Testing and is the direct responsibility of Subcommittee E07.08 on Leak www.astm.org.
4
Testing Method. AvailablefromAVS,AmericanVacuumSociety,335E.45thStreet,NewYork,
CurrenteditionapprovedJune1,2018.PublishedJuly2018.Originallyapproved N.Y., 10017.
5
in 1982. Last previous edition approved in 2012 as E908-98 (2012). DOI: C.D. Ehrlich and J.A. Basford, Journal of Vac. Sci, Technology, A(10), 1992,
10.1520/E0908-98R18. pp. 1–17.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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E908 − 98 (2018)
3.1.3 The tracer gas is removed from the chamber, and the 3.3.1 The tube is closely coupled to the leak, and has a
unknown leak is allowed to discharge into it until the sensor vent/fill valve to allow gas filling or positioning of the slug, or
response equals that o
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM 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: E908 − 98 (Reapproved 2012) E908 − 98 (Reapproved 2018)
Standard Practice for
1
Calibrating Gaseous Reference Leaks
This standard is issued under the fixed designation E908; 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 This practice covers procedures for calibrating leak artifacts of a specified gas, that may be used for determining the
response of leak detectors, or in other situations where a known small flow of gas is required. The purpose of this practice is to
establish calibration without reference to other calibrated leaks in as straightforward a manner as possible using the likeliest
available equipment. While the uncertainties associated with these procedures will most likely be greater than those obtained via
traceable calibration chains (on the order of 10 %), these procedures allow independent means of establishing or verifying the
leakage rate from leak artifacts of questionable history, or when traceable leak artifacts are not available.
1.2 Two types of leaks are considered:
1.2.1 Type I—Pressure to vacuum.
1.2.2 Type II—Pressure to atmosphere.
1.3 Three calibration methods are described under each type of reference leak:
1.3.1 Method A—Accumulation comparison, using a known volume of gas at specified conditions of temperature and pressure
as a reference.
1.3.2 Method B—Accumulation comparison, using a leak artifact calibrated using Method A.
1.3.3 Method C—Displacement of a liquid slug, by the leak, in capillary tube of known dimensions.
1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
3
E425 Definitions of Terms Relating to Leak Testing (Withdrawn 1991)
3
E427 Practice for Testing for Leaks Using the Halogen Leak Detector Alkali-Ion Diode (Withdrawn 2013)
3
E479 Guide for Preparation of a Leak Testing Specification (Withdrawn 2014)
F134 Test Methods for Determining Hermeticity of Electron Devices with a Helium Mass Spectrometer Leak Detector
3
(Withdrawn 1996)
2.2 Other Documents:
4
AVS 2.2-1968 Method for Vacuum Leak Calibration
5
Recommended Practices for the Calibration and Use of Leaks
1
This practice is under the jurisdiction of ASTM Committee E07 on Nondestructive Testing and is the direct responsibility of Subcommittee E07.08 on Leak Testing
Method.
Current edition approved Nov. 15, 2012June 1, 2018. Published November 2012July 2018. Originally approved in 1982. Last previous edition approved in 20042012 as
E908 - 98 (2004).(2012). DOI: 10.1520/E0908-98R12.10.1520/E0908-98R18.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
The last approved version of this historical standard is referenced on www.astm.org.
4
Available from AVS, American Vacuum Society, 335 E. 45th Street, New York, N.Y., 10017.
5
C.D. Ehrlich and J.A. Basford, Journal of Vac. Sci, Technology, A(10), 1992, pp. 1–17.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E908 − 98 (2018)
3. Summary of Practice
3.1 Method A—Accumulation comparison, using a known volume of tracer gas:
3.1.1 This method uses a closed chamber of nonreactive material having a means of removing all tracer gas and a connection
to the tracer sensor.
3.1.2 A small, known quantity of tr
...