1、Designation: E1603/E1603M 11 (Reapproved 2017)Standard Practice forLeakage Measurement Using the Mass Spectrometer LeakDetector or Residual Gas Analyzer in the Hood Mode1This standard is issued under the fixed designation E1603/E1603M; the number immediately following the designation indicates the y
2、earof 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. Scope1.1 This practice covers procedures for testing the sourc
3、esof gas leaking at the rate of 1 108Pa m3/s (1 109standard-cm3/s at 0C) or greater. These test methods may beconducted on any object that can be evacuated and to the otherside of which helium or other tracer gas may be applied. Theobject must be structurally capable of being evacuated topressures o
4、f 0.1 Pa (approximately 103torr).1.2 Three test methods are described;1.2.1 Test Method AFor the object under test capable ofbeing evacuated, but having no inherent pumping capability.1.2.2 Test Method BFor the object under test with integralpumping capability.1.2.3 Test Method CFor the object under
5、 test as in TestMethod B, in which the vacuum pumps of the object under testreplace those normally used in the leak detector (LD).1.3 UnitsThe values stated in either SI or std-cc/sec unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents: theref
6、ore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard
7、 to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for the
8、Development of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E1316 Terminology for Nondestructive Examinations2.2 ASNT Standards:3SNT-TC-1A Recommended Practice for Per
9、sonnel Qualifi-cation and Certification in Nondestructive TestingANSI/ASNT-CP-189 Standard for Qualification and Certifi-cation of Nondestructive Testing Personnel2.3 Military Standard:MIL-STD-410 Nondestructive Testing Personnel Qualifica-tion and Certification42.4 AIA Standard:NAS-410 Certificatio
10、n and Qualification of NondestructiveTest Personnel53. Terminology3.1 DefinitionsFor definitions of terms used in thispractice, see Terminology E1316.4. Summary of Practice4.1 These test methods covered in this practice require ahelium LD that can provide a system sensitivity of 10 % or lessof the i
11、ntended leakage rate to be measured.4.2 Test Method AThis test method is used to helium leaktest objects that are capable of being evacuated to a reasonabletest pressure by the LD pumps during an acceptable length oftime (see Fig. 1). This requires that the object be clean and dry.Auxiliary vacuum p
12、umps having greater capacity than those inthe LD may be used in conjunction with them. The leak testsensitivity will be reduced under these conditions.1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.08 on
13、LeakTesting Method.Current edition approved June 1, 2017. Published July 2017. Originally approvedin 1994. Last previous edition approved in 2011 as E1603 - 11. DOI: 10.1520/E1603_E1603M-11R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at se
14、rviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available fromAmerican Society for Nondestructive Testing (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:/www.asnt.org.4Available from Standa
15、rdization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.5Available from Aerospace Industries Association of America, Inc. (AIA), 1000Wilson Blvd., Suite 1700,Arlington, VA22209-3928, http:/www.aia-aerospace.org.Copyright AST
16、M International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Stan
17、dards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.14.3 Test Method BThis test method is used to leak testequipment that can provide its own vacuum (that is, equipmentthat has a built-in pumping system) at least to a level of a fewhun
18、dred pascals (a few torr) or lower. Refer to Fig. 2.4.4 Test Method CWhen a vacuum system is capable ofproducing internal pressures of less than 2 102Pa (2 104torr) in the presence of leaks, these leaks may be located andevaluated by the use of either a residual gas analyzer (RGA) orby using the spe
19、ctrometer tube and controls from a conven-tional MSLD, provided that the leakage is within the sensitivityrange of the RGAor MSLD under the conditions existing in thevacuum system. Refer to Fig. 3.5. Significance and Use5.1 Test Method AThis test method is the most frequentlyused in leak testing com
20、ponents. Testing of components iscorrelated to a standard leak, and the actual leak rate ismeasured. Acceptance is based on the maximum systemallowable leakage. For most production needs, acceptance isbased on acceptance of parts leaking less than an establishedleakage rate, which will ensure safe p
21、erformance over theprojected life of the component. Care must be exercised toensure that large systems are calibrated with the standard leaklocated at a representative place on the test volume. As thevolume tends to be large (1 m3) and there are often lowconductance paths involved, a check of the re
22、sponse time aswell as system sensitivity should be made.5.2 Test Method BThis test method is used for testingvacuum systems either as a step in the final test of a newsystem or as a maintenance practice on equipment used formanufacturing, environmental test, or conditioning parts. Aswith Test Method
23、A, the response time and a system sensitivitycheck may be required for large volumes.5.3 Test Method CThis test method is to be used onlywhen there is no convenient method of connecting the LD tothe outlet of the high-vacuum pump. If a helium LD is used andthe high-vacuum pump is an ion pump or cryo
24、pump, leaktesting is best accomplished during the roughing cycle, as thesepumps leave a relatively high percentage of helium in thehigh-vacuum chamber. This will limit the maximum sensitivitythat can be obtained.6. Basis of Application6.1 Personnel QualificationIf specified in the contractualagreeme
25、nt, personnel performing examinations to these testmethods shall be qualified in accordance with a nationallyrecognized NDT personnel qualification practice or standard,such as ANSI/ASNT-CP-189, SNT-TC-1A, MIL-STD-410,NAS-410, or a similar document and certified by the employeror certifying agency,
26、as applicable. The practice or standardused and its applicable revision shall be identified in thecontractual agreement between the using parties.7. Interferences7.1 Series leaks with an unpumped volume between thempresent a difficult if not impossible problem in helium leaktesting. Although the tra
27、ce gas enters the first leak readilyenough since the pressure difference of helium across the firstleak is approximately one atmosphere, it may take many hoursto build up the partial pressure of helium in the volumebetween the two leaks so that enough helium enters the vacuumsystem to be detected by
28、 the LD. This type of leak occursfrequently under the following conditions:7.1.1 Double-welded joints and lap welds,7.1.2 Double O-rings,7.1.3 Threaded joints,7.1.4 Ferrule and flange-type tubing fittings,7.1.5 Casting with internal voids,7.1.6 Flat polymer gaskets, and7.1.7 Unvented O-ring grooves.
29、FIG. 1 Test Method AFIG. 2 Test Method BFIG. 3 Test Method CE1603/E1603M 11 (2017)27.2 In general, the solution is proper design to eliminatethese conditions; however, when double seals must be used, anaccess port between them should be provided for attachment tothe LD. Leaks may then be located fro
30、m each side of the seal.The access port can be sealed or pumped continuously afterrepair by a holding pump (large vacuum system).7.3 Temporarily plugged leaks often occur because of poormanufacturing techniques. Water, cleaning solvent, plating,flux, grease, paint, etc. are common problems. These pr
31、oblemscan be eliminated to a large extent by proper preparation of theparts before leak testing. Proper degreasing, vacuum baking,and testing before plating or painting are desirable.7.4 The time constant for evacuation and for the rise of thehelium signal is inversely proportional to the pumping sp
32、eedand directly proportional to the volume being evacuated. 5 V/S (1)Low-conductance tubing, or any other flow impedance, canreduce the pumping speed of the system very significantly, thusextending the system response time constant. If such animpedance connects two volumes under test, a LD connectio
33、nto each volume should be provided.7.5 When unusually long pumping times are necessary, allof the connections not being tested should be protected fromcontinuous exposure to the helium. This will reduce undesiredhigh-helium background levels due to permeation of heliumthrough the O-rings. This can b
34、e effected by double-seals (withevacuation of the space between), or sometimes by moreinformal shielding approaches.TEST METHOD AHELIUM LEAK TESTING OFCOMPONENTS/SYSTEMS USING THE LD8. Apparatus8.1 Leak Detector, having a minimum detectable leak rate asrequired by the test sensitivity.8.2 Auxiliary
35、Pumps, capable of evacuating the object to betested to a low enough pressure that the LD may be connected.8.3 Suitable Connector and Valves, to connect to the LD testport. Compression fitting and metal tubing should be used inpreference to a vacuum hose.8.4 Standard Leaks of Both Capsule Type (Conta
36、ining ItsOwn Helium Supply) and Capillary Type, an actual leak that isused to simulate the reaction of the test system to a heliumleak. The leak rate of the standard leak used for the systemcalibration shall be equal to or less than the acceptance level(maximum permissible leakage rate). Temperature
37、 correctionof the permeation capsule-type standard leaks should beperformed when the ambient temperature has a difference of3C 5F from the calibration temperature of the standardleak. The leakage rate error may become significant (12 %)without temperature correction.8.5 Vacuum Gauge, to read the pre
38、ssure before the LD isconnected when using an auxiliary roughing pump.8.6 Helium Tank and Regulator, with attached helium probehose and jet for locating leaks.8.7 Test Component/System Enclosure (Hood)Either arigid structure or heavy plastic cover to contain and surroundthe test part totally in heli
39、um tracer gas.9. Instrument Calibration9.1 Attach the capsule leak to the LD and tune the LD toachieve the desired sensitivity scale in accordance with themanufacturers instructions. Allow sufficient time for the flowrate from the capsule leak to equilibrate. The permeation-typecapsule leak should b
40、e stored with the shutoff valve (if present)open, and the leak should be allowed to equilibrate to ambienttemperature for several hours.9.2 Adjust the LD readout to correspond to the temperature-corrected standard leak value in accordance with the manufac-turers instructions.NOTE 1Valve closures may
41、 be accomplished automatically on someLDs, and some counterflow-type MSLDs require continued use of theroughing pump during testing. Refer to the manufacturers operatingmanual.9.3 Disconnect the capsule standard leak from the LD andconnect the test system to the LD.9.4 Instrument calibration shall b
42、e performed prior to andupon completion of each test. Any change in sensitivity shallbe evaluated to determine if the test results are valid.10. System Calibration and Test Procedure10.1 For small-volume tests (a few litres and less) or whenthe standard leak cannot be attached directly to the testco
43、mponent, the instrument calibration shall be used for thesystem calibration. The correction factor (CF) used to multiplythe instrument calibration value for the system leak rate is one.10.2 For large-volume systems, attach one of the standardleaks to the test system at a location that provides the l
44、owestconductance path to the LD.NOTE 2If using a capsule leak, open the calibrated leak (CL) andpump isolation valves, and close the calibration valve. Turn on the CLvacuum pump. Refer to Fig. 4.10.3 Evacuate the device to be tested until near equilibriumpressure is reached on the rough vacuum gauge
45、. Open thevalve to the LD and check the background helium concentra-tion. When the helium background is equal to or less than onehalf the acceptance level (maximum permissible leakage rate)and stable, close the valve(s) to the roughing pumps.10.4 System Calibration or Procedure Qualification:10.4.1
46、Record the helium background level.10.4.2 Open the valve of the system standard leak (calibra-tion valve) attached to the test component/system (Fig. 4).NOTE 3If using a capillary leak, apply helium of one atmosphere tothe standard leak. For the capsule standard leaks, close the pump isolationvalve
47、immediately prior to opening the calibration valve.10.4.3 Graph the LD response as a function of time until asteady-state condition is reached. Refer to Fig. 5.10.4.4 Close the standard leak valve, and reduce the heliumbackground of the test component/system to the same level asthat obtained before
48、system calibration. It may be necessary toE1603/E1603M 11 (2017)3open roughing pump valves and use the roughing pumps toexpedite the reduction of the helium background.10.4.5 Calculate the LD CF for adjusting the instrumentcalibration reading to a system calibration reading. For tests onlarge-volume
49、 systems, the amplitude response of a leak in thesystem is less than the amplitude response from the instrumentcalibration standard leak.10.4.5.1 This CF should be calculated at either the time atwhich a steady-state response (SS) is reached or at the time atwhich the LD response is 63 % of the change. This shall be theminimum test period. The formula for the CF at this test timeis as follows:CF 5CLcLR 2 BR(2)where:CLc= temperature-corrected standard leak rate,LR = indicated LD reading (0.63 SS or SS) at the end of thetest period ( or 5 re
