1、Designation: A 340 03aStandard Terminology ofSymbols and Definitions Relating to Magnetic Testing1This standard is issued under the fixed designation A 340; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 differential equations s
3、o 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 glossary to be consist
4、ent 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 range of induct
5、ionBb biased inductionBdremanent inductionBdmremanenceBdHdenergy product(BdHd)mmaximum energy productBDincremental inductionBiintrinsic inductionBmmaximum induction in a hysteresis loopBmaxmaximum induction in a flux current loopBrresidual inductionBrsretentivityBssaturation inductioncf crest factor
6、CM 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 field strength
7、DH 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 (from an assumedpea
8、k value of magnetizing currentHmmaximum magnetic field strength in a hyster-esis loopHmaxmaximum magnetic field strength in a flux-current loopHpac magnetic field strength (from a measuredpeak value of exciting current)Htinstantaneous magnetic field strength (coinci-dent with Bmax)Hzac magnetic fiel
9、d 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 length+ (also
10、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 specimenNDdemagnetizing fac
11、torN1turns in a primary winding1This 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 June 10, 2003. Published July 2003. Originallyapproved in 1949. Last p
12、revious edition approved in 2003 as A 340 03.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.N2turns in a secondary windingN1I/,1ac excitationp magnetic pole strength3 permeanceP active (real) powerPaapparent powerPa (B;f)specific ap
13、parent 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 lossPwwinding loss (copper loss)Pzexciting p
14、owerPz (B;f)specific exciting powerQmmagnetic storage factor5 reluctanceR1core resistanceRwwinding resistanceS lamination factor (stacking factor)SCM symmetrically cyclically magnetized conditionTcCurie temperaturew lamination widthWhhysteresis loop lossa linear expansion, coefficient (average)Dx in
15、cremental toleranceb hysteretic angleg loss anglecos g magnetic power factorgpproton gyromagnetic ratioGmmagnetic constantd densityk susceptibilityac Permeabilities:aideal permeabilityLinductance permeabilityDL incremental inductance permeability0dinitial dynamic permeabilityppeak permeabilityDpincr
16、emental peak permeabilityiinstantaneous permeabilityzimpedance permeabilityDzincremental impedance permeabilitydc Permeabilities: normal permeabilityabsabsolute permeabilityddifferential permeabilityDincremental permeabilityeffeffective circuit permeabilityiintrinsic permeabilityDiincremental intrin
17、sic 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 susceptibilityx0initial susceptibilityv angular fre
18、quency 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, Pthe product of the rms current, I,inanel
19、ectrical circuit, the rms voltage, E, across the circuit, andthe cosine of the angular phase difference, u between thecurrent and the voltage.P 5 EI cosuNOTE 1The portion of the active power that is expended in amagnetic core is the total core loss, Pc.aging coefficientthe percentage change in a spe
20、cific mag-netic property resulting from a specific aging treatment.NOTE 2The 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 due to a normalor specified aging condition.NO
21、TE 3This term implies a deterioration of the magnetic properties ofmagnetic materials for electronic and electrical applications, unlessotherwise specified.air-gap magnetic field strength, Hgthe magnetic fieldstrength required to produce the induction existing at somepoint in a nonmagnetic gap in a
22、magnetic circuit.NOTE 4In the cgs-emu system of units, Hgis numerically equal to theinduction existing at such a point and exceeds the magnetic field strengthin the magnetic material.amorphous alloya semiprocessed alloy produced by a rapidquenching, direct casting process resulting in metals withnon
23、crystalline 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 inthe SI system of units.anisotropic materiala material in w
24、hich 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.anisotropy of loss 5Pc B;f! lPc B;f! twhere:Pc (B;f) l= speci
25、fic core loss value with flux parallel to therolling direction, W/lb W/kg, andA 340 03a2Pc (B;f) t= specific core loss value with flux perpendicularto the rolling direction, W/lb W/kg.NOTE 5This definition of anisotropy normally applies to electricalsteels with measurements made in an Epstein frame
26、at a flux density of 15kG 1.5 T and a frequency of 60 Hz (see Test Method A 343).anisotropy of permeabilitythe ratio of relative peak perme-ability measured with flux parallel to the rolling direction tothe relative peak permeability measured with flux perpen-dicular to the rolling direction.anisotr
27、opy 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.NOTE 6This definition of anisotropy normally applies to electricalsteels with measurements mad
28、e in an Epstein frame at a flux density of 15kG 1.5 T and a frequency of 60 Hz (see Test Method A 343).antiferromagnetic materiala feebly magnetic material inwhich almost equal magnetic moments are lined up antipar-allel to each other. Its susceptibility increases as the tem-perature is raised until
29、 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 containing inductive impedance. The compo-nents of this impedance as a
30、 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 divided by the active mass of the specimen, that is,volt-amperes per unit ma
31、ss. 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 direction of the induction.Bloch walla domain wall in which the magnetic
32、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 1021erg/gauss or9 274 078 3 1024J/T).cgs-emu system of unitsthe system for me
33、asuring 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 the magnetic induction to zero after thematerial has been symmetrically
34、 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, Hcsthe maximum value of coercive field strengththat can be attained wh
35、en 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 milled from sheet or strip material.Individual pieces usually have an insula
36、ting 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 comprised of smallparticles of electrically insulated metallic ferromagne
37、ticmaterial. 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 insulating surface coating whichreduces interlaminar eddy current loss
38、es 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 eddy currents in a magnetic material that issymetrically cyclically magne
39、tized.NOTE 7The voltage is generally assumed to be across the parallelcombination of core inductance, L1, and core resistance, R1.core loss, ac, incremental, PcDthe core loss in a magneticmaterial when the material is subjected simultaneously to adc biasing magnetizing force and an alternating magne
40、tizingforce.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-pended per unit mass of magnetic material in which there isa cyclically varying
41、 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.NOTE 8Measurements of core loss are normally made with sinusoi-dally alternating induction, or t
42、he results are corrected for deviations fromthe 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 a specifiedfrequency, f, divided by the effective volume of the core.NOTE 9T
43、his parameter is normally used only for non-laminated coressuch as ferrite and powdered cores.core platea generic term for any insulating material, formedmetallurigically or applied externally as a thin surfacecoating, on sheet or strip stock used in the construction oflaminated and tape wound cores
44、.coupling coefficient, k8the ratio of the mutual inductanceA 340 03a3between 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 alternating quantity to its rms value.NOTE 10For a sinusoidal variation
45、 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 induced voltage) of theexciting current supplied to a coil which is linked with aferromagnetic
46、core.current, ac exciting, Ithe rms value of the total currentsupplied to a coil that is linked with a ferromagnetic core.NOTE 11Exciting current is measured under the condition that anyother coil linking the same core carries no current.current, ac, magnetizing, Imthe rms value of the magnetiz-ing
47、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 inductor winding will produce a unidirectionalmagnetic field in the magnetic material.customary u
48、nitsa set of industry-unique units from thecgs-emu system of units and U.S. inch-pound systems andunits derived from the two systems.NOTE 12Examples of customary units used in ASTM A06 standardsinclude:Quantity NameQuantitySymbol Unit Name Unit SymbolMagnetic field strength H oersted OeMagnetic indu
49、ction (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 origin of the axes.demagnetization curvethe portion of a flux versus dccurrent plot (dc hysteresi
