1、Designation:E2261/E2261M12Standard Practice forExamination of Welds Using the Alternating Current FieldMeasurement Technique1This standard is issued under the fixed designation E2261/E2261M;the number immediately following the designation indicates the yearof original adoption or,in the case of revi
2、sion,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.Scope*1.1 This practice describes procedures to be followed duringalternating current field measurement examinatio
3、n of welds forbaseline and service-induced surface breaking discontinuities.1.2 This practice is intended for use on welds in anymetallic material.1.3 This practice does not establish weld acceptance crite-ria.1.4 UnitsThe values stated in either inch-pound units orSI units are to be regarded separa
4、tely as standard.The valuesstated in each system might not be exact equivalents;therefore,each system shall be used independently of the other.Combin-ing values from the two systems may result in nonconformancewith the standard.1.5 This standard does not purport to address all of thesafety concerns,
5、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:2E543 Specification for Agencies Performing Nonde
6、structiveTestingE1316 Terminology for Nondestructive Examinations2.2 ASNT Standard:3SNT-TC-1A Personnel Qualification and Certification inNondestructive TestingANSI/ASNT-CP-189 Standard for Qualification and Certifi-cation of Nondestructive Testing Personnel3.Terminology3.1 DefinitionsFor definition
7、s of terms relating to thispractice refer to Terminology E1316,Section A,CommonNDT terms,and Section C,Electromagnetic testing.Thefollowing definitions are specific to the alternating current fieldmeasurement technique:3.2 Definitions:3.2.1 excitera device that generates a time varying elec-tromagne
8、tic field,usually a coil energized with alternatingcurrent(AC);also known as a transmitter.3.2.2 detectorone or more coils or elements used to senseor measure a magnetic field;also known as a receiver.3.2.3 uniform fieldas applied to nondestructive testingwith magnetic fields,the area of uniform mag
9、netic field overthe surface of the material under examination produced by aparallel induced alternating current,which has been passedthrough the weld and is observable beyond the direct couplingof the exciting coil.3.2.4 graduated fieldas applied to nondestructive testingwith magnetic fields,a magne
10、tic field having a controlledgradient in its intensity.3.3 Definitions of Terms Specific to This Standard:3.3.1 alternating current field measurement systemtheelectronic instrumentation,software,probes,and all associatedcomponents and cables required for performing weld exami-nation using the altern
11、ating current field measurement tech-nique.3.3.2 operational reference standarda reference standardwith specified artificial slots,used to confirm the operation ofthe system.3.3.3 Bxthe x component of the magnetic field,parallel tothe weld toe,the magnitude of which is proportional to thecurrent den
12、sity set up by the electric field.3.3.4 Bzthe z component of the magnetic field normal tothe inspected base metal/heat affected zone surface,the mag-nitude of which is proportional to the lateral deflection of theinduced currents in the plane of that surface.3.3.5 X-Y Plotan X-Y graph with two ortho
13、gonal compo-nents of magnetic field plotted against each other.1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.07 onElectromagnetic Method.Current edition approved Nov.1,2012.Published November 2012.Origin
14、allyapproved in 2003.Last previous edition approved in 2007 as E2261-07.DOI:10.1520/E2261_E2261M-12.2For 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 Documen
15、t Summary page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken
16、,PA 19428-2959.United States1 3.3.6 time base plotsthese plot the relationship betweenBx or Bz values with time.3.3.7 surface plotfor use with array probes.This type ofplot has one component of the magnetic field plotted over anarea,typically as a color contour plot or 3-D wire frame plot.3.3.8 data sample ratethe rate at which data is digitizedfor display and recording,in data points per second.3.3.9 configuration datastandardization data and instru-mentation settings for a particular probe sto
