ASTM E499-95(2006)
(Test Method)Standard Test Methods for Leaks Using the Mass Spectrometer Leak Detector in the Detector Probe Mode
Standard Test Methods for Leaks Using the Mass Spectrometer Leak Detector in the Detector Probe Mode
SIGNIFICANCE AND USE
Test Method A is frequently used to test large systems and complex piping installations that can be filled with a trace gas. Helium is normally used. The test method is used to locate leaks but cannot be used to quantify except for approximation. Care must be taken to provide sufficient ventilation to prevent increasing the helium background at the test site. Results are limited by the helium background and the percentage of the leaking trace gas captured by the probe.
Test Method B is used to increase the concentration of trace gas coming through the leak by capturing it within an enclosure until the signal above the helium background can be detected. By introducing a calibrated leak into the same volume for a recorded time interval, leak rates can be measured.
SCOPE
1.1 These test methods cover procedures for testing and locating the sources of gas leaking at the rate of 4.5 x 10 13 mol/s (1 x 108 Std cm 3/s) or greater. The test may be conducted on any device or component across which a pressure differential of helium or other suitable tracer gas may be created, and on which the effluent side of the leak to be tested is accessible for probing with the mass spectrometer sampling probe.
1.2 Two test methods are described:
1.2.1 Test Method A - Direct probing, and
1.2.2 Test Method B - Accumulation.
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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Standards Content (Sample)
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Designation:E499–95 (Reapproved 2006)
Standard Test Methods for
Leaks Using the Mass Spectrometer Leak Detector in the
,
1 2
Detector Probe Mode
This standard is issued under the fixed designation E499; 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.
This specification has been approved for use by agencies of the Department of Defense.
1. Scope ANSI/ASNT CP-189 ASNT Standard for Qualification and
5
Certification of Nondestructive Testing Personnel
1.1 These test methods cover procedures for testing and
−13
locating the sources of gas leaking at the rate of 4.5 310
3. Terminology
−8 3
3
mol/s (1 310 Std cm /s) or greater. The test may be
3.1 Definitions—For definitions of terms used in this stan-
conductedonanydeviceorcomponentacrosswhichapressure
dard, see Terminology E1316, Section E.
differential of helium or other suitable tracer gas may be
created, and on which the effluent side of the leak to be tested
4. Summary of Test Methods
is accessible for probing with the mass spectrometer sampling
6
4.1 Section1.8oftheLeakageTestingHandbook willbeof
probe.
value to some users in determining which leak test method to
1.2 Two test methods are described:
use.
1.2.1 Test Method A—Direct probing, and
4.2 These test methods require a leak detector with a
1.2.2 Test Method B—Accumulation.
−12 −7
full-scale readout of at least 4.5 310 mol/s (1 310 Std
1.3 This standard does not purport to address all of the
3 3
cm /s) on the most sensitive range, a maximum 1-min drift of
safety concerns, if any, associated with its use. It is the
zero and sensitivity of 65% of full scale on this range, and
responsibility of the user of this standard to establish appro-
62% or less on others (see 7.1). The above sensitivities are
priate safety and health practices and determine the applica-
those obtained by probing an actual standard leak in atmo-
bility of regulatory limitations prior to use.
sphere with the detector, or sampling, probe, and not the
sensitivityofthedetectortoastandardleakattacheddirectlyto
2. Referenced Documents
4 the vacuum system.
2.1 ASTM Standards:
4.3 Test Method A, Direct Probing (see Fig. 1), is the
E1316 Terminology for Nondestructive Examinations
simplest test, and may be used in parts of any size, requiring
2.2 Other Documents:
only that a tracer gas pressure be created across the area to be
SNT-TC-1A Recommended Practice for Personnel Qualifi-
5 tested, and the searching of the atmospheric side of the area be
cation and Certification in Nondestructive Testing
with the detector probe. This test method detects leakage and
its source or sources. Experience has shown that leak testing
1
−11 −6 3
3
These test methods are under the jurisdiction of ASTM Committee E07 on
down to 4.5 310 mol/s (1 310 Std cm /s) in factory
NondestructiveTestingandarethedirectresponsibilityofSubcommitteeE07.08on
environments will usually be satisfactory if reasonable precau-
Leak Testing Method.
tionsagainstreleasinggaslikethetracergasinthetestareaare
Current edition approved Dec. 1, 2006. Published January 2007. Originally
approvedin1973.Lastpreviouseditionapprovedin2000asE499-95(2000).DOI:
observed, and the effects of other interferences (Section 6) are
10.1520/E0499-95R06.
considered.
2
(Atmospheric pressure external, pressure above atmospheric internal). This
4.4 Test Method B, Accumulation Testing (see Fig. 2),
document covers the Detector Probe Mode described in Guide E432.
3
provides for the testing of parts up to several cubic metres in
The gas temperature is referenced to 0°C. To convert to another gas reference
temperature, T , multiply the leak rate by (T +273)/273.
ref ref volumeasinFig.2(a)orinportionsoflargerdevicesasinFig.
4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
6
the ASTM website. Marr,J.William,“LeakageTestingHandbook,”preparedforLiquidPropulsion
5
AvailablefromAmericanSocietyforNondestructiveTesting(ASNT),P.O.Box Section,JetPropulsionLaboratory,NationalAeronauticsandSpaceAdministration,
28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org. Pasadena, CA, Contract NAS 7-396, June 1961.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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E499–95 (2006)
FIG. 1 Method A
2(b). This is accomplished by allowing the leakage to accu- 5. Personnel Qualification
mulate in the chamber for a fixed period,
...
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