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【英文标准名称】:StandardTestMethodforAlternating-CurrentMagneticPropertiesofMaterialsatLowMagneticFluxDensityUsingtheVoltmeter-Ammeter-Wattmeter-VarmeterMethodand25-cmEpsteinFrame
【原文标准名称】:在低磁通密度下用万用表法和25厘米艾普斯亭(Epstein)框测定材料的交流磁特性的标准试验方法
【标准号】:ASTMA889/A889M-2003(2008)
【标准状态】:现行
【国别】:美国
【发布日期】:2003
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:A06.01
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:alternating-current;ammeter;coreloss;Epstein;excitingpower;induction;magnetic;magneticmaterial;magnetictest;permeability;powerfrequency;varmeter;voltmeter;wattmeter;A-C(alternating-current)magneticproperties;Coreloss--alternating-c
【摘要】:Thistestmethodmaybeusedtodeterminethespecificcoreloss,specificreactivepower,specificexcitingpower,inductancepermeability,andimpedancepermeabilityofflat-rolledmagneticmaterialsoverawiderangeofinductionsandatfrequenciesupto400Hzforsymmetricallymagnetizedtestsamples.Thesemeasurementsareusedbytheproduceranduseroftheflat-rolledmaterialforqualitycontrolpurposes.Thefundamentalassumptioninherentinthesemeasurementsisthattheycanbecorrelatedwiththeelectromagneticcharacteristicsofacorefabricatedfromtheflat-rolledmaterial.1.1Thistestmethodcoverstestsforthemagneticpropertiesofbasicflat-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-rolledmagneticmaterialsunderacmagnetization.1.4Thefrequencyrangeofthistestmethodisnormallythatofthecommercialpowerfrequencies50to60Hz.Itisalsoacceptableformeasurementsatfrequenciesfrom25to400Hz.Thistestmethodiscustomarilyusedonnonorientedelectricalsteelsatinductionsupto10kG[1.0T]andforgrain-orientedelectricalsteelsatinductionsupto15kG[1.5T].1.5Forreactiveproperties,bothfluxandcurrentwaveformsintroducelimitations.Overitsrangeofusefulinductions,thevarmeterisvalidforthemeasurementofreactivevolt-amperes(vars)andinductancepermeability.Forthemeasurementoftheseproperties,itissuggestedthattestinductionsbelimitedtovaluessufficientlylowthatthemeasuredvaluesofvarsdonotdifferbymorethan15%(Note1)fromthosecalculatedfromthemeasuredvaluesofexcitingvolt-amperesandcoreloss.Note18212;Thislimitationisplacedonthistestmethodinconsiderationofthenonlinearnatureofthemagneticcircuit,whichleadstoadifferencebetweenvarsbasedonfundamentalfrequencycomponentsofvoltageandcurrentandcurrentafterharmonicrejectionandvarscomputedfromrmscurrent,voltage,andwattvalueswhenoneormoreofthesequantitiesarenonsinusoidal.1.6ThistestmethodshallbeusedinconjunctionwithPracticeA34/A34M.1.7Explanationofterms,symbols,anddefinitionsusedmaybefoundinthevarioussectionsofthistestmethod.TheofficiallistofdefinitionsandsymbolsmaybefoundinTerminologyA340.1.8ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.Withinthisstandard,SIunitsareshowninbrackets.1.9Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortoitsuse.
【中国标准分类号】:H21
【国际标准分类号】:29_030
【页数】:5P.;A4
【正文语种】:英语


【英文标准名称】:DentalDuplicatingMaterial
【原文标准名称】:牙科用复制材料
【标准号】:ANSI/ADA20-1972
【标准状态】:作废
【国别】:美国
【发布日期】:1972
【实施或试行日期】:
【发布单位】:美国国家标准学会(ANSI)
【起草单位】:ANSI
【标准类型】:()
【标准水平】:()
【中文主题词】:牙科材料;材料;牙科学
【英文主题词】:Dentalmaterials;Dentistry;Duplicating;Materials
【摘要】:
【中国标准分类号】:C33
【国际标准分类号】:11_060_10
【页数】:
【正文语种】:英语