Designation:D4352–90(Reapproved1997)e1AnAmericanNationalStandardStandardTestMethodforDeterminationofMagneticMaterialImpuritiesinElectricalGradeMagnesiumOxide1ThisstandardisissuedunderthefixeddesignationD4352;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.e1NOTE—KeywordswereaddededitoriallyinOctober1997.1.Scope1.1Thistestmethodcoversthedeterminationofmagneticmaterialcontentoffusedelectricallyinsulatingmagnesiumoxidepowders.1.2Thevaluesstatedinacceptablemetricunitsaretoberegardedasthestandard.1.3Thisstandarddoesnotpurporttoaddressthesafetyproblemsassociatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimita-tionspriortouse.2.ReferencedDocuments2.1ASTMStandards:D2755TestMethodforSamplingandReductiontoTestWeightofElectricalGradeMagnesiumOxide23.SummaryofTestMethod3.1Asampleofelectricalgrademagnesiumoxideisplacedintothemagneticanalyzersampletube.Themagneticmateri-alscontentisthenreaddirectlyaspercentcontained.4.SignificanceandUse4.1Freeironinmagnesiumoxidepowderisdetrimentaltoelectricalcharacteristicsofthepowderwhenusedaselectricalinsulationinheatingelements.5.Apparatus5.1MagneticAnalyzerandInstrumentCalibrationStan-dards.35.2LaboratoryBalance,capableofweighing13060.1g.6.CalibrationandStandardization6.1Themagneticsanalyzershouldbecalibratedaccordingtotheinstrumentinstructionsmanual.NOTE1—ThisproceduremayvarysomewhatwhenusingananalyzerotherthantheNetronicsMagneticsAnalyzer.7.Procedure7.1ObtainasampletobetestedinaccordancewithTestMethodD2755.7.2Weigha13060.1gspecimen.7.3Setsampleweightdialto130.7.4Setrangeselectorswitchto0.1.7.5Zeroinstrumentwithemptysampletubeusingthenulladjustment.7.6Transfertestsampletosampletube.7.7Insertsampletubeintosamplecompartmentoftheinstrum...
