Designation:A712−14StandardTestMethodforElectricalResistivityofSoftMagneticAlloys1ThisstandardisissuedunderthefixeddesignationA712;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthemeasurementofelectricalresistivityofstriporbarspecimensofsoftmagneticalloys.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2A34/A34MPracticeforSamplingandProcurementTestingofMagneticMaterials3.SummaryofTestMethod3.1Theelectricalresistanceofa0.25-mlong(minimum)testspecimenismeasuredwithaKelvin-typeresistancebridgeoradigitalohmmeterorthepotentiometer-ammetermethod.Theresistivityisthencalculatedfromtheresistancemeasure-mentandthedimensionsofthespecimenandisknownastheelectricalresistivityofthematerial.Thisvalueisequaltotheresistancebetweenoppositefacesofacubeofunitdimensions.4.SignificanceandUse4.1Thistestmethodissuitableforthemeasurementoftheelectricalresistivityofspecimensofsoftmagneticmaterials.4.2Thereproducibilityandrepeatabilityofthistestmethodaresuchthatitissuitablefordesign,specificationacceptance,serviceevaluation,qualityassurance,andresearchanddevel-opment.5.Apparatus5.1Kelvin-typeresistancebridgeoradigitalohmmeter(Note1)oradcpotentiometeranddcammeterprovidingresistancemeasurementstoanaccuracywithin0.5%oftheacceptedtruevalue.NOTE1—Adigitalmultimeterwithafour-wireresistancemeasuringcapabilitycanbesubstitutedforadigitalohmmeter.6.Sampling6.1Samplesshallberepresentativeofthematerialinthephysicalconditionasshippedor...
