Designation:B84−07(Reapproved2019)StandardTestMethodforTemperature-ResistanceConstantsofAlloyWiresforPrecisionResistors1ThisstandardisissuedunderthefixeddesignationB84;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversdeterminationofthechangeofresistancewithtemperatureofalloywiresusedforresistancestandardsandprecisionresistorsforelectricalapparatus.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafety,health,andenvironmentalpracticesanddeter-minetheapplicabilityofregulatorylimitationspriortouse.1.4Thisinternationalstandardwasdevelopedinaccor-dancewithinternationallyrecognizedprinciplesonstandard-izationestablishedintheDecisiononPrinciplesfortheDevelopmentofInternationalStandards,GuidesandRecom-mendationsissuedbytheWorldTradeOrganizationTechnicalBarrierstoTrade(TBT)Committee.2.SignificanceandUse2.1ProcedureAcoversthedeterminationoftheequationofthecurverelatingresistanceandtemperaturewherethecurveapproximatesaparabola.Thistestmethodmaybeusedforwireofanymetaloralloyoverthetemperatureintervalappropriatetothematerial.2.2ProcedureBcoversthedeterminationofthemeantemperaturecoefficientofresistanceforwireofanymetaloralloyoverthetemperatureintervalappropriatetothematerial.3.Apparatus3.1Theapparatusformakingthetestshallconsistofoneormorebathsformaintainingthespecimenatthedesiredtemperatures;thermometersformeasuringthetemperaturesofthebaths;andsuitablemeansformeasuringtheresistanceofthespecimen.DetailsoftheapparatusaregiveninSections4to6.4.Baths4.1Bathsforusefrom−65to+15°Cmayconsistoftoluol,orequivalent.4.2Bathsforuseabove15to250°...
