2024年5月5日发(作者：)

Designation:A773/A773M–01

StandardTestMethodfor

dcMagneticPropertiesofMaterialsUsingRingand

PermeameterProcedureswithdcElectronic

Hysteresigraphs

1

ThisstandardisissuedunderthefixeddesignationA773/A773M;thenumberimmediatelyfollowingthedesignationindicatestheyear

oforiginaladoptionor,inthecaseofrevision,rinparenthesesindicatestheyearoflastreapproval.

Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.

1.1Thistestmethodprovidesdchysteresigraphprocedures

(B-Hloopmethods)forthedeterminationofbasicmagnetic

propertiesofmaterialsintheformofring,toroidal,link,

double-lappedEpsteincores,orotherstandardshapesthatmay

becut,stamped,machined,orgroundfromcast,compacted,

sintered,forged,udestestsfornormal

inductionandhysteresistakenunderconditionsofcontinuous

sweepmaybevaried,either

manuallyorautomaticallyatdifferentportionsofthecurves

lapsedtimefortracingahysteresisloop

iscommonly10to120sperloop.

1.2Thevaluesandequationsstatedincustomary(cgs-emu

andinch-pound)orSIunitsaretoberegardedseparatelyas

thisstandard,SIunitsareshowninbrackets.

Thevaluesstatedineachsystemmaynotbeexactequivalents;

therefore,eachsystemshallbeusedindependentlyoftheother.

Combiningvaluesfromthetwosystemsmayresultinnoncon-

formancewiththisstandard.

1.3Thisstandarddoesnotpurporttoaddressallofthe

safetyconcerns,ifany,e

responsibilityoftheuserofthisstandardtoestablishappro-

priatesafetyandhealthpracticesanddeterminetheapplica-

bilityofregulatorylimitationspriortouse.

ncedDocuments

2.1ASTMStandards:

2

A34/A34MPracticeforSamplingandProcurementTest-

ingofMagneticMaterials

A341/A341MTestMethodforDirectCurrentMagnetic

PropertiesofMaterialsUsingD-CPermeametersandthe

BallisticTestMethods

ThistestmethodisunderthejurisdictionofASTMCommitteeA06on

MagneticPropertiesandisthedirectresponsibilityofSubcommitteeA06.01onTest

Methods.

CurrenteditionapprovedJune10,ally

eviouseditionapprovedin1996asA773–96.

2

ForreferencedASTMstandards,visittheASTMwebsite,,or

contactASTMCustomerServiceatservice@ualBookofASTM

Standardsvolumeinformation,refertothestandard’sDocumentSummarypageon

theASTMwebsite.

1

A343/A343MTestMethodforAlternating-CurrentMag-

neticPropertiesofMaterialsatPowerFrequenciesUsing

Wattmeter-Ammeter-VoltmeterMethodand25-cmEpstein

TestFrame

A596/A596MTestMethodforDirect-CurrentMagnetic

PropertiesofMaterialsUsingtheBallisticMethodand

RingSpecimens

2.2Other:

IECPublication404-4:MagneticMaterials—Part4:Meth-

odsofMeasurementofdcMagneticPropertiesofIronand

Steel(1995)

3

yofTestMethod

3.1Asinmakingmostmagneticmeasurements,aspecimen

iswoundwithanexcitingwinding(theprimary)andasearch

coil(thesecondary)formeasuringthechangeinfl

excitingcurrent,I,isappliedtotheprimarywinding,a

magneticfield,H,isproducedinthecoil,andthisinturn

producesmagneticflormspeci-

mensthatdonotcontainairgaps,suchasringsamples,allof

theexcitingcurrentisusedtomagnetizethespecimen,andH

isproportionaltoIinaccordancewiththefollowingequation:

H5KI

(1)

where:

H=magneticfieldstrength,Oe[A/m];

I=currentintheexcitingcoilA;and

K=constantdeterminedbythenumberofprimaryturns

themagneticpathlengthofthespecimenandsystem

ofunits.

3.1.1Themagneticfluxmaybedeterminedbyintegration

oftheinstantaneouselectromotiveforcethatisinducedinthe

secondarycoilwhenthefluxisincreasedordecreasedbya

tantaneousvoltage,e,isequalto:

e52NK

1

df

dt

(2)

or

AvailablefromAmericanNationalStandardsInstitute,25W.43rdSt.,4th

Floor,NewYork,NY10036.

3

Copyright©ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959,UnitedStates.

1

A773/A773M–01

FIG.1BlockDiagramofRingTestApparatus

1

f5

KN

1

*

edt

where:

dt=timedifferential,

N=numberofturns,and

K

1

=10

−8

forcgs-emusystem,orK

1

=1forSIsystem.

Thefluxfcanbeobtainedif*

canbeaccomplishedbyseveralmeans,asdescribedinASTM

STP526.(

1)

4

Themostcommonmethodusesanelectronic

integratorconsistingofahigh-gaindcamplifierwithresistive-

ationshipto*edtis:

1

E5

RC

*

edt(3)

where:

E=outputvoltage,V;

R=inputresistanceoftheintegratorinthesecondary

circuit,V;and

C=thefeedbackcapacitance,F.

Bycombiningthetwoequations:

ERC

fNK

1

f5

KN

orE5

RC

1

(4)

blockdiagramof

ingpermeameters,thevalue

ofHinthegapisgenerallynotproportionaltoIthatflows

ecases,thevalue

ofHisdeterminedbyintegrationoftheelectromotiveforce

thatisinducedinanHcoil(orChattockpotentiometer)orfrom

thesignaldevelopedbyaHallprobewhichisplacednearthe

inganHcoil,thedeterminationofHis

accomplishedwithanHintegratorinexactlythesamemanner

asthatusedtodeterminefluxwiththeBintegratordescribedin

ingaHallsensor,theHvaluesaredetermined

cases,theHversusIrelationshipmaybesufficientlylinear

from0tothecoercivefieldstrength(H

c

)ofthematerialunder

cases,itisacceptabletodeterminethesecond

quadrantofthehysteresisloopbydeterminingHfromthe

valueofIintheexcitingwinding.

ficanceandUse

4.1Hysteresigraphtestingpermitsmorerapidandefficient

collectionofdchysteresis(B-Hloop)dataascomparedtothe

pointbypointballisticTestMethods

A341/A341Mand

A596/uracyandprecisionoftestingis

esigraphsarepar-

ticularlydesirablefortestingofsemihardandhardmagnetic

materialswhereeithertheentiresecondquadrant(demagneti-

zationcurve)orentirehysteresisloopisofprimaryconcern.

4.2Providedthetestspecimenisrepresentativeofthebulk

sampleorlot,thistestmethodiswellsuitedfordesign,

specificationacceptance,serviceevaluationandresearchand

development.

erences

5.1Testmethodsusingsuitablering-typespecimensarethe

preferredmethodsfordeterminingthebasicmagneticproper-

r,thistestmethodhasseveral

adequateinsidediameterto

outsidediameterratiosaremaintainedinthetestspecimens,

themagneticfieldstrengthwillbeexcessivelynonuniform

throughoutthetestmaterialandthemeasuredparameters

icquality

2

Ifthevoltage,E,isappliedtotheYaxisofanX-Yrecorder,

theYdeflectionofthepenisproportionaltotheflux,f.

3.1.2Measurementsofmagneticfieldstrengthandfluxby

thehysteresigraphmethodisillustratedintheblockdiagramof

temconsistsofamagnetizingpowersource,an

excitingcurrentcontroller,anelectronicfluxintegrator,anda

tingcurrentisappliedtothecoil,a

voltageproportionaltoIisproducedacrosstheshuntresistor

ltage

determinesthevalueofH.

3.1.3Inthetestingofhardmagneticmaterials,orsoft

magneticmaterialsintheformofwire,barsorrods,itis

showninthe

4

Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof

thistestmethod.