Designation:F312−08(Reapproved2016)StandardTestMethodsforMicroscopicalSizingandCountingParticlesfromAerospaceFluidsonMembraneFilters1ThisstandardisissuedunderthefixeddesignationF312;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thesetestmethodscoverthedeterminationofthesizedistributionandquantityofparticulatemattercontaminationfromaerospacefluidsisolatedonamembranefilter.Themicroscopicaltechniquesdescribedmayalsobeappliedtootherproperlypreparedsamplesofsmallparticles.Twotestmethodsaredescribedforsizingparticlesasfollows:1.1.1TestMethodA—Particlesizesaremeasuredasthediameterofacirclewhoseareaisequaltotheprojectedareaoftheparticle.1.1.2TestMethodB—Particlesizesaremeasuredbytheirlongestdimension.1.2Thetestmethodsareintendedforapplicationtoparticlecontaminationdeterminationofaerospacefluids,gases,surfaces,andenvironments.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.4Thesetestmethodsdonotprovideforsizingparticlessmallerthan5µm.NOTE1—Resultsofthesemethodsaresubjecttovariablesinherentinanystatisticalmethod.Theuseofthesemethodsasastandardforinitiallyestablishinglimitsshouldbeavoidedunlessampletolerancesarepermis-sible.1.5Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2F302PracticeforFieldSamplingofAerospaceFluidsinContainersF303PracticesforSamplingforParticlesinAerospaceFluidsandComponentsF311PracticeforProcessingAerospaceLiquidSamplesforParticulateContaminationAnalysisUsingMembraneFil-tersF314MethodsofTestforIdentificationofMetallicandFibrousContaminantsinAerospa...
