Designation:D2715−92(Reapproved2012)StandardTestMethodforVolatilizationRatesofLubricantsinVacuum1ThisstandardisissuedunderthefixeddesignationD2715;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationoftheratesofvolatilizationoflubricantsinathermal-vacuumenvironmentatpressuresandtemperaturesnecessarytoobtainameasurablerateofevaporation,orevidenceofdecomposition.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2E296PracticeforIonizationGageApplicationtoSpaceSimulatorsE297MethodsforCalibratingIonizationVacuumGageTubes33.SummaryofTestMethod3.1Aknownquantityofspecimenisplacedinathermalvacuumbalancesystemandtheevaporatedmaterialiscon-densedonacoldplate.Theweightofthespecimeniscontinuallyrecordedasafunctionoftimefornominalconstantsurfacearea.4.SignificanceandUse4.1Thistestmethodprovidesdataforcomparisonoftheevaporationrateoflubricantsusedinunshieldedbearingsinthespaceenvironment.5.Apparatus5.1RecordingVacuumMicrobalance,withcapacityof1gormore,sensitivityof0.01mgorless,zerostabilityof0.025mgorlessfor8hwithrangesofweightchangeof10mgormore,and0.1mgorless,capableofbeingpumpedto10−5Pa(10−7torr)orless.5.1.1WhenProcedureBforthemorevolatilesamplesisused,thevacuumrequirementshallbe10−2Pa(10−4torr)orless.5.2VacuumSystem—Apumpingsystemcapableofmain-tainingastartingpressureof10−6to10−5Pa(10−8to10−7torr)(5.1.1).Anopticallydensebafflesystemshouldbeusedtoensurefreedomfromback-streaming.Aconventionalb...
