ASTM_A_598_-_A_598M_-_02_2015.pdf

Designation:A598/A598M02(Reapproved 2015)Standard Test Method forMagnetic Properties of Magnetic Amplifier Cores1This standard is issued under the fixed designation A598/A598M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the mag-netic performance of fully processed cores for magneticamplifier-type applications.1.2 Tests may be conducted at excitation frequencies of 60,400,1600 Hz,or higher frequencies.1.3 Permissible core sizes for this test method are limitedonly by the available power supplies and the range andsensitivity of the instrumentation.1.4 At specified values of full-wave sinusoidal-currentexcitation,Hmax,this test method provides procedures ofdetermining the corresponding value of maximum induction,Bmax.1.5 At specified values of half-wave sinusoidal-currentexcitation,this test method provides procedures for determin-ing the residual induction,Br.1.6 At increased specified values of half-wave sinusoidal-current excitation,this test method provides procedures fordetermining the dc reverse biasing magnetic field strength,H1,required to reset the induction in the core material past Brto avalue where the total induction change,B1,becomes approxi-mately one third of the induction change,2 Bp.It also providesprocedures for determining the additional dc reset magneticfield strength,H,which,combined with H1,is the valuerequired to reset the induction in the core material past Brto avalue where the total induction change,B2,becomes approxi-mately two thirds of the induction change 2 Bp.1.7 This test method specifies procedures for determiningcore gain from the corresponding biasing and inductionchanges,H and B.1.8 This test method covers test procedures and require-ments for evaluation of finished cores which are to be used inmagnetic-amplifier-type applications.It is not a test for basic-material magnetic properties.1.9 This test method shall be used in conjunction withPractice A34/A34M.1.10 Explanations of symbols and abbreviated definitionsappear in the text of this test method.The official symbols anddefinitions are listed in Terminology A340.1.11 The values and equations stated in customary(cgs-emuand inch-pound)or SI units are to be regarded separately asstandard.Within this test method,SI units are shown inbrackets.The values stated in each system may not be exactequivalents;therefore,each system shall be used independentlyof the other.Combining values from the two systems mayresult in nonconformance with this test method.1.12 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2A34/A34M Practice for Sampling and Procurement Testingof Magnetic MaterialsA340 Terminology of Symbols and Definitions Relating toMagnetic TestingA596/A596M Test Method for Direct-Current MagneticProperties of Materials Using the Ballistic Method andRing Specimens3.Terminology3.1 DefinitionsBelow is a list of symbols and definitionsas used in this test method.The official list of symbols anddefinitions may be found in Terminology A340.(See Table 1where indicated).3.2 Symbols:1This test method is under the jurisdiction of ASTM Committee A06 onMagnetic Properties and is the direct responsibility of Subcommittee A06.01 on TestMethods.Current edition approved April 1,2015.Published April 2015.Originallyapproved in 1969.Last previous edition approved in 2007 as A598/A598M02(2007).DOI:10.1520/A0598_A0598M-02R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 A=cross-sectional area of test specimen corematerial,cm2m2.A1=ac ammeter for primary circuit,half-wave,average-responsive,A.A2=dc ammeter for H1biasing winding,A.A3=dc ammeter for H2biasing winding,A.A4=dc milliammeter for ac voltage calibrator,V.BmaxBr=change in test specimen induction,under half-wave sinusoidal-current excitation specifiedfor this measurement.Bm=maximum induction in a sine-current SCM acflux-current loop Gauss Tesla(Note 1).Bp=maximum value of induction in the sine-current half-wave CM flux-current loop,for thereset test Gauss Tesla(Note 1).Br=residual induction in an ac sine-current flux-current loop Gauss Tesla.B=change in magnetic induction Gauss Tesla(Table 1).B1=change in induction in the flux-curren