1、Designation: A340 03a (Reapproved 2011)Standard Terminology ofSymbols and Definitions Relating to Magnetic Testing1This standard is issued under the fixed designation A340; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONIn preparing this glossary of terms, an attempt has been made to avoid, where possible, vectoranalysis and different
3、ial equations so as to make the definitions more intelligible to the average workerin the field of magnetic testing. In some cases, rigorous treatment has been sacrificed to securesimplicity, but it is believed that none of the definitions will prove to be misleading.It is the intent of this glossar
4、y to be consistent in the use of symbols and units with those found inANSI/IEEE 260-1978 and USA Standard Y 10.5-1968.Part 1Symbols Used in Magnetic TestingSymbol Terma cross-sectional area of B coilA cross-sectional area of specimenA8 solid areaBHmagnetic inductionmagnetic flux densityDB excursion
5、range of inductionBb biased inductionBdremanent inductionBdmremanenceBdHdenergy product(BdHd)mmaximum energy productBDincremental inductionBiintrinsic inductionBmmaximum induction in a hysteresis loopBmaxmaximum induction in a flux current loopBrresidual inductionBrsretentivityBssaturation induction
6、cf crest factorCM cyclically magnetized conditiond lamination thicknessDBdemagnetizing coefficientdf distortion factorDmmagnetic dissipation factorE exciting voltageE1induced primary voltageE2induced secondary voltageEfflux voltsf cyclic frequency in hertz magnetomotive forceff form factorH magnetic
7、 field strengthDH excursion range of magnetic field strengthHbbiasing magnetic field strengthHccoercive field strengthHciintrinsic coercive field strengthHcscoercivityHddemagnetizing field strengthHDincremental magnetic field strengthHgair gap magnetic field strengthHLac magnetic field strength (fro
8、m an assumedpeak value of magnetizing currentHmmaximum magnetic field strength in ahyster esis loopHmaxmaximum magnetic field strength in aflux- current loopHpac magnetic field strength (from a measuredpeak value of exciting current)Htinstantaneous magnetic field strength (coinci-dent with Bmax)Hzac
9、 magnetic field strength force (from an as-sumed peak value of exciting current)I ac exciting current (rms value)Icac core loss current (rms value)Idcconstant currentImac magnetizing current (rms value)J magnetic polarizationk8 coupling coefficient, flux path length,1effective flux path length,ggap
10、length+ (also f N) flux linkage+mmutual flux linkageL self inductanceL1core inductanceLDincremental inductanceLiintrinsic inductanceLmmutual inductanceL0initial inductanceLsseries inductanceLwwinding inductancem magnetic momentM magnetizationm total mass of a specimenm1active mass of a specimenNDdem
11、agnetizing factor1This terminology is under the jurisdiction of ASTM Committee A06 onMagnetic Properties and is the direct responsibility of Subcommittee A06.92 onTerminology and Definitions.Current edition approved May 1, 2011. Published August 2011. Originallyapproved in 1949. Last previous editio
12、n approved in 2003 as A34003a. DOI:10.1520/A0340-03AR11.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.N1turns in a primary windingN2turns in a secondary windingN1I/,1ac excitationp magnetic pole strength3 permeanceP active (real) p
13、owerPaapparent powerPa (B;f)specific apparent powerPctotal core lossPc (B;f)specific core lossPcDincremental core lossPenormal eddy current core lossPDeincremental eddy current core lossPhnormal hysteresis core lossPDhincremental hysteresis core lossPqreactive (quadrature) powerPrresidual core lossP
14、wwinding loss (copper loss)Pzexciting powerPz (B;f)specific exciting powerQmmagnetic storage factor5 reluctanceR1core resistanceRwwinding resistanceS lamination factor (stacking factor)SCM symmetrically cyclically magnetized conditionTcCurie temperaturew lamination widthWhhysteresis loop lossa linea
15、r expansion, coefficient (average)Dx incremental toleranceb hysteretic angleg loss anglecos g magnetic power factorgpproton gyromagnetic ratioGmmagnetic constantd densityk susceptibilityac Permeabilities:aideal permeabilityLinductance permeabilityDL incremental inductance permeability0dinitial dynam
16、ic permeabilityppeak permeabilityDpincremental peak permeabilityiinstantaneous permeabilityzimpedance permeabilityDzincremental impedance permeabilitydc Permeabilities: normal permeabilityabsabsolute permeabilityddifferential permeabilityDincremental permeabilityeffeffective circuit permeabilityiint
17、rinsic permeabilityDiincremental intrinsic permeabilitymmaximum permeability0initial permeabilityrrelative permeabilityv(also Gm) space permeabilityrevreversible permeability8/cot g figure of meritn reluctivityp the numeric 3.1416r resistivityf magnetic fluxfN flux linkage (see +)x mass susceptibili
18、tyx0initial susceptibilityv angular frequency in radians per secondPart 2Definition of Terms Used in Magnetic Testingac excitation, N1I/1the ratio of the rms ampere-turns ofexciting current in the primary winding of an inductor to theeffective flux path length of the inductor.active (real) power, Pt
19、he product of the rms current, I,inanelectrical circuit, the rms voltage, E, across the circuit, andthe cosine of the angular phase difference, u between thecurrent and the voltage.P 5 EI cosuDISCUSSIONThe portion of the active power that is expended in amagnetic core is the total core loss, Pc.agin
20、g coefficientthe percentage change in a specific mag-netic property resulting from a specific aging treatment.DISCUSSIONThe aging treatments usually specified are:(a) 100 h at 150C or(b) 600 h at 100C.aging, magneticthe change in the magnetic properties of amaterial resulting from metallurgic change
21、 due to a normalor specified aging condition.DISCUSSIONThis term implies a deterioration of the magneticproperties of magnetic materials for electronic and electrical applica-tions, unless otherwise specified.air-gap magnetic field strength, Hgthe magnetic fieldstrength required to produce the induc
22、tion existing at somepoint in a nonmagnetic gap in a magnetic circuit.DISCUSSIONIn the cgs-emu system of units, Hgis numerically equalto the induction existing at such a point and exceeds the magnetic fieldstrength in the magnetic material.amorphous alloya semiprocessed alloy produced by a rapidquen
23、ching, direct casting process resulting in metals withnoncrystalline structure.ampere (turn), Athe unit of magnetomotive force in the SIsystem of units. The symbol A represents the unit of electriccurrent, ampere, in the SI system of units.ampere per metre, A/mthe unit of magnetic field strength int
24、he SI system of units.anisotropic materiala material in which the magnetic prop-erties differ in various directions.anisotropy of lossthe ratio of the specific core loss measuredwith flux parallel to the rolling direction to the specific coreloss with flux perpendicular to the rolling direction.anis
25、otropy of loss 5Pc B;f! lPc B;f! twhere:Pc (B;f) l= specific core loss value with flux parallel to therolling direction, W/lb W/kg, andPc (B;f) t= specific core loss value with flux perpendicularto the rolling direction, W/lb W/kg.DISCUSSIONThis definition of anisotropy normally applies to elec-tric
26、al steels with measurements made in an Epstein frame at a fluxdensity of 15 kG 1.5 T and a frequency of 60 Hz (see Test MethodA343).A340 03a (2011)2anisotropy of permeabilitythe ratio of relative peak perme-ability measured with flux parallel to the rolling direction tothe relative peak permeability
27、 measured with flux perpen-dicular to the rolling direction.anisotropy of permeability 5prlprtwhere:prl= relative peak permeability value with flux parallel tothe rolling direction, andprt= relative peak permeability value with flux perpen-dicular to the rolling direction.DISCUSSIONThis definition o
28、f anisotropy normally applies to elec-trical steels with measurements made in an Epstein frame at a fluxdensity of 15 kG 1.5 T and a frequency of 60 Hz (see Test MethodA343).antiferromagnetic materiala feebly magnetic material inwhich almost equal magnetic moments are lined up antipar-allel to each
29、other. Its susceptibility increases as the tem-perature is raised until a critical (Nel) temperature isreached; above this temperature the material becomes para-magnetic.apparent power, Pathe product (volt-amperes) of the rmsexciting current and the applied rms terminal voltage in anelectric circuit
30、 containing inductive impedance. The compo-nents of this impedance as a result of the winding will belinear, while the components as a result of the magnetic corewill be nonlinear. The unit of apparent power is the volt-ampere, VA.apparent power, specific, Pa(B;f)the value of the apparentpower divid
31、ed by the active mass of the specimen, that is,volt-amperes per unit mass. The values of voltage andcurrent are those developed at a maximum value of cycli-cally varying induction B and specified frequency f.area, Athe geometric cross-sectional area of a magnetic pathwhich is perpendicular to the di
32、rection of the induction.Bloch walla domain wall in which the magnetic moment atany point is substantially parallel to the wall surface. Seealso domain wall.Bohr magnetona constant that is equal to the magneticmoment of an electron because of its spin. The value of theconstant is (9 274 078 3 1021er
33、g/gauss or9 274 078 3 1024J/T).cgs-emu system of unitsthe system for measuring physicalquantities in which the base units are the centimetre, gram,and second, and the numerical value of the magneticconstant, Gm, is unity.coercive field strength, Hcthe (dc) magnetic field strengthrequired to restore
34、the magnetic induction to zero after thematerial has been symmetrically cyclically magnetized.coercive field strength, intrinsic, Hcithe (dc) magnetic fieldstrength required to restore the instrinsic magnetic inductionto zero after the material has been symmetrically cyclicallymagnetized.coercivity,
35、 Hcsthe maximum value of coercive field strengththat can be attained when the magnetic material is symmetri-cally cyclically magnetized to saturation induction, BS.core, laminateda magnetic component constructed bystacking suitably thin pieces of magnetic material which arestamped, sheared, or mille
36、d from sheet or strip material.Individual pieces usually have an insulating surface coatingto minimize eddy current losses in the assembled core.core, matedtwo or more magnetic core segments assembledwith the magnetic flux path perpendicular to the matingsurface.core, powder (dust)a magnetic core co
37、mprised of smallparticles of electrically insulated metallic ferromagneticmaterial. These cores are characterized by low hysteresis andeddy current losses.core, tape-wounda magnetic component constructed by thespiral winding of strip material onto a suitable mandrel. Thestrip material usually has an
38、 insulating surface coating whichreduces interlaminar eddy current losses in the finished core.core loss, ac eddy current, incremental, PDethe power losscaused by eddy currents in a magnetic material that iscyclically magnetized.core loss, ac eddy current, normal, Pethe power losses asa result of ed
39、dy currents in a magnetic material that issymetrically cyclically magnetized.DISCUSSIONThe voltage is generally assumed to be across theparallel combination of core inductance, L1, and core resistance, R1.core loss, ac, incremental, PcDthe core loss in a magneticmaterial when the material is subject
40、ed simultaneously to adc biasing magnetizing force and an alternating magnetizingforce.core loss, residual, Prthe portion of the core loss power, Pc,which is not attributed to hysteresis or eddy current lossesfrom classical assumptions.core loss, ac, specific, Pc(B;f)the active power (watts) ex-pend
41、ed per unit mass of magnetic material in which there isa cyclically varying induction of a specified maximum value,B, at a specified frequency, f.core loss, ac, (total), Pcthe active power (watts) expended ina magnetic circuit in which there is a cyclically alternatinginduction.DISCUSSIONMeasurement
42、s of core loss are normally made withsinusoidally alternating induction, or the results are corrected fordeviations from the sinusoidal condition.core loss densitythe active power (watts) expended in amagnetic core in which there is a cyclically varying induc-tion of a specified maximum value, B, at
43、 a specifiedfrequency, f, divided by the effective volume of the core.DISCUSSIONThis parameter is normally used only for non-laminatedcores such as ferrite and powdered cores.core platea generic term for any insulating material, formedmetallurigically or applied externally as a thin surfacecoating,
44、on sheet or strip stock used in the construction oflaminated and tape wound cores.coupling coefficient, k8the ratio of the mutual inductancebetween two windings and the geometric mean of theindividual self-inductances of the windings.crest factor, cfthe ratio of the maximum value of a periodi-cally
45、alternating quantity to its rms value.A340 03a (2011)3DISCUSSIONFor a sinusoidal variation the crest factor is =2.Curie temperature, Tcthe temperature above which a fer-romagnetic material becomes paramagnetic.current, ac core loss, Icthe rms value of the in-phasecomponent (with respect to the induc
46、ed voltage) of theexciting current supplied to a coil which is linked with aferromagnetic core.current, ac exciting, Ithe rms value of the total currentsupplied to a coil that is linked with a ferromagnetic core.DISCUSSIONExciting current is measured under the condition thatany other coil linking th
47、e same core carries no current.current, ac, magnetizing, Imthe rms value of the magnetiz-ing component (lagging with respect to applied voltage) ofthe exciting current supplied to a coil that is linked with aferromagnetic core.current, dc, Idca steady-state dc current. A dc currentflowing in an indu
48、ctor winding will produce a unidirectionalmagnetic field in the magnetic material.customary unitsa set of industry-unique units from thecgs-emu system of units and U.S. inch-pound systems andunits derived from the two systems.DISCUSSIONExamples of customary units used in ASTM A06standards include:Qu
49、antity NameQuantitySymbol Unit Name Unit SymbolMagnetic field strength H oersted OeMagnetic induction (magneticflux density)B gauss GSpecific core loss Pc(b;f) watt/pound W/lbcyclically magnetized condition, CMa magnetic material isin a cyclically magnetized condition when, after having beensubjected to a sufficient number of identical cycles ofmagnetizing field, it follows identical hysteresis or flux-current loops on successive cycles which are not symmetri-cal with respect to the or
