Designation:D4438−13(Reapproved2018)´1StandardTestMethodforParticleSizeDistributionofCatalystsandCatalystCarriersbyElectronicCounting1ThisstandardisissuedunderthefixeddesignationD4438;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ε1NOTE—KeywordsrevisededitoriallyinMay2018.1.Scope1.1Thistestmethodcoversthedeterminationofparticlesizedistributionofcatalystandcatalystcarrierparticlesusinganelectroconductivesensingmethodandisoneofseveralvaluablemethodsforthemeasurementofparticlesize.1.2Therangeofparticlesizesinvestigatedwas20to150µm(seeIEEE/ASTMSI10)equivalentsphericaldiameter.Thetechniqueiscapableofmeasuringparticlesaboveandbelowthisrange.Theinstrumentusedforthismethodisanelectriccurrentpathofsmalldimensionsthatismodulatedbyindi-vidualparticlepassagethroughanaperture,andproducesindividualpulsesofamplitudeproportionaltotheparticlevolume.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D1193SpecificationforReagentWaterE177PracticeforUseoftheTermsPrecisionandBiasinASTMTestMethodsE691PracticeforConductinganInterlaboratoryStudytoDeterminethePrecisionofaTestMethodIEEE/ASTMSI10StandardforUseoftheInternationalSystemofUnits(SI):TheModernMetricSystem3.SummaryofTestMethod3.1Acarefullydispersed,dilutesuspensionofthesampleinabeakerfilledwithanele...
