Designation:D3635−13(Reapproved2021)StandardTestMethodforDissolvedCopperInElectricalInsulatingOilByAtomicAbsorptionSpectrophotometry1ThisstandardisissuedunderthefixeddesignationD3635;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofcopperinneworusedelectricalinsulatingoilofpetroleumoriginbyatomicabsorptionspectrophotometry.1.2Thelowestlimitofdetectabilityisprimarilydependentuponthemethodofatomization,butalsoupontheenergysource,thefuelandoxidant,andthedegreeofelectricalexpansionoftheoutputsignal.Thelowestdetectableconcen-trationisusuallyconsideredtobeequaltotwicethemaximumvariationofthebackground.Forflameatomization,thelowerlimitofdetectabilityisgenerallyintheorderof0.1ppmor0.1mg/kg.Fornon-flameatomization,thelowerlimitofdetect-abilityislessthan0.01ppm.1.3ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.5Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.ReferencedDocuments2.1ASTMStandards:2D1193SpecificationforReagentWaterD3487SpecificationforMineralInsulatingOilUsedinElectricalApparatusD5222SpecificationforHighFire-PointMineralElectricalInsulatingOils3.SummaryofTestMethod3.1Thetestspecimenofoilisfilteredanddilutedwithanappropriateorganicsolventandanalyzedinanatomicabsorp-tions...