ASTM_E_1816_-_12.pdf

Designation:E181612Standard Practice forUltrasonic Testing Using Electromagnetic AcousticTransducer(EMAT)Techniques1This standard is issued under the fixed designation E1816;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This practice covers procedures for the use of electro-magnetic acoustic transducers(EMATs)for specific ultrasonicexamination applications.Recommendations are given forspecific applications for using EMAT techniques to detectflaws through both surface and volumetric examinations aswell as to measure thickness.1.2 These procedures recommend technical details andguidelines for the reliable and reproducible ultrasonic detectionof flaws and thickness measurements using electromagneticacoustic transducers for both the pulsing and receiving ofultrasonic waves.The EMAT techniques described herein canbe used as a basis for assessing the serviceability of variouscomponents nondestructively,as well as for process control inmanufacturing.1.3 These procedures cover noncontact techniques for cou-pling ultrasonic energy into materials through the use ofelectromagnetic fields.Surface,Lamb,longitudinal,and shearwave modes are discussed.1.4 These procedures are intended to describe specificEMAT applications.These procedures are intended for appli-cations in which the user has determined that the use of EMATtechniques can offer substantial benefits over conventionalpiezoelectric search units.It is not intended that EMATtechniques should be used in applications in which conven-tional techniques and applications offer superior benefits(referto Guide E1774).1.5 These procedures are applicable to any material inwhich acoustic waves can be introduced electromagnetically.This includes any material that is either electrically conductiveor ferromagnetic.1.6 The procedures outlined in this practice address provenEMAT techniques for specific applications;they do not purportto address the only variation or all variations of EMATtechniques to address the given applications.Latitude inapplication techniques is offered where options are consideredappropriate.1.7 The values stated in inch-pound units are to be regardedas the standard.The values given in parentheses are forinformation only.1.8 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:2E114 Practice for Ultrasonic Pulse-Echo Straight-BeamContact TestingE494 Practice for Measuring Ultrasonic Velocity in Materi-alsE543 Specification for Agencies Performing NondestructiveTestingE587 Practice for Ultrasonic Angle-Beam Contact TestingE797 Practice for Measuring Thickness by Manual Ultra-sonic Pulse-Echo Contact MethodE1316 Terminology for Nondestructive ExaminationsE1774 Guide for Electromagnetic Acoustic Transducers(EMATs)2.2 ASNT Standards:3SNT-TC-1A Recommended Practice for Personnel Qualifi-cations and Certification in Nondestructive TestingANSI/ASNT CP-189 Standard for Qualification and Certifi-cation of Nondestructive Testing Personnel2.3 Aerospace Industries Association Standard:NAS 410 Certification and Qualification of NondestructiveTest Personnel41This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.06 onUltrasonic Method.Current edition approved Nov.1,2012.Published November 2012.Originallyapproved in 1996.Last previous edition approved in 2007 as E1816-07.DOI:10.1520/E1816-12.2For 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 Document Summary page onthe ASTM website.3Available fromAmerican Society for Nondestructive Testing(ASNT),P.O.Box28518,1711 Arlingate Ln.,Columbus,OH 43228-0518,http:/www.asnt.org.4Available from Aerospace Industries Association of America,Inc.(AIA),1000Wilson Blvd.,Suite 1700,Arlington,VA22209-3928,http:/www.aia-aerospace.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.Terminology3.1 Definitions:Related terminology is defined in Terminol-ogy E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 bulk wavean ultrasonic wave,either longitudinal orshear mode,used in nondestructive testing to interrogate thevolume of a material.3.2.2 electromagnetic acoustic transducer(EMAT)anelectromagnetic device for converting electrical energy intoacoustical energy in the