Designation:F798–97(Reapproved2002)StandardPracticeforDeterminingGetteringRate,SorptionCapacity,andGasContentofNonevaporableGettersintheMolecularFlowRegion1ThisstandardisissuedunderthefixeddesignationF798;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thispracticedescribestechniquesfordeterminingget-teringrates,sorptioncapacity,andgascontentofnonevapo-rablegettersinthemolecularflowregion.1.2Proceduresforactivatinggettersandfordetermininggasevolutionratesarealsogiven.1.3Thevarioustestsdescribedaremostlydestructiveinnature.Ingeneral,thetestsaresemiquantitative,buttheycanbeexpectedtoyieldcomparativeinformationonasinglelaboratorybasis.Multilaboratoryreproducibilitycanbeestab-lishedonlywithround-robintesting.Singlelaboratorypreci-sionis615%forgetteringrateandsorptioncapacity.Multi-laboratoryreproducibilityisestimatedat650%.Gascontentmeasurementsmayhaveasubstantiallygreatererrorduetotheuncertaintyofthetemperature.1.4Adversegetter-deviceinteractionssuchascontamina-tionandpoisoningcanoccur.Suchproblemsarebeyondthescopeofthispractice.Theuserandsellershouldestablishcriteriaforcontrollingproblemssuchaschemicalreactions,looseparticles,getterlocation,etc.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.SpecifichazardstatementsaregiveninSection4.2.ReferencedDocuments2.1ASTMStandards:E296PracticeforIonizationGageApplicationtoSpaceSimulators2E297TestMethodforCalibratingIonizationVacuumGageTubes32.2AmericanVacuumSocietyStandards:RecommendedPractice2.3ProcedureforCalibratingGasAnalyzersoftheMassSpectrometerType4RecommendedPractices6.2,6.4,and6.5ProceduresforCalibratingPressur...
