Designation:A889/A889M−14StandardTestMethodforAlternating-CurrentMagneticPropertiesofMaterialsatLowMagneticFluxDensityUsingtheVoltmeter-Ammeter-Wattmeter-VarmeterMethodand25-cmEpsteinFrame1ThisstandardisissuedunderthefixeddesignationA889/A889M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoverstestsforthemagneticpropertiesofbasicflat-rolledmagneticmaterialsatpowerfrequencies(25to400Hz)usinga25-cmEpsteintestframeandthe25-cmdouble-lap-jointedcore.1.2ThemagneticpropertiesofmaterialsaredeterminedfrommeasurementsonEpsteincorespecimenswiththecoreandtestcoilstreatedasthoughtheyconstitutedaseries-parallelequivalentcircuit(Fig.A1.1)forthefundamentalfrequencyofexcitationwheretheapparentparallelinductance,L1,andresistance,R1,areattributabletothetestspecimen.1.3Thistestmethodissuitableforthedeterminationofcoreloss,rmsvolt-amperes,rmsexcitingcurrent,reactivevolt-amperes,andrelatedpropertiesofflat-rolledmagneticmateri-alsunderacmagnetization.1.4Thefrequencyrangeofthistestmethodisnormallythatofthecommercialpowerfrequencies50to60Hz.Itisalsoacceptableformeasurementsatfrequenciesfrom25to400Hz.Thistestmethodiscustomarilyusedonnonorientedelectricalsteelsatinductionsupto10kG[1.0T]andforgrain-orientedelectricalsteelsatinductionsupto15kG[1.5T].1.5Forreactiveproperties,bothfluxandcurrentwaveformsintroducelimitations.Overitsrangeofusefulinductions,thevarmeterisvalidforthemeasurementofreactivevolt-amperes(vars)andinductancepermeability.Forthemeasurementoftheseproperties,itissuggestedthattestinductionsbelimitedtovaluessufficientlylowthatthemeasuredvaluesofvarsdonotdifferbymorethan15%(Note1)fromthosecalculatedfromthemeasuredvaluesofexcitingvolt-amperesandcoreloss.NOTE1—Thislimitationisplacedonthistestmethodinconsiderationofthenonlinearnatureofthemagneticcir...
