ASTM_E_1932_-_12.pdf

Designation:E193212Standard Guide forAcoustic Emission Examination of Small Parts1This standard is issued under the fixed designation E1932;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 guide covers techniques for conducting acousticemission(AE)examinations of small parts.It is confined toexamination objects(or defined regions of larger objects)where there is low AE signal attenuation throughout theexamination region.This eliminates the consideration of com-plex attenuation factor corrections and multiple sensor andarray placements based on overcoming signal losses overdistances.1.2 The guide assumes a typical AE examination as onewhere there is a controlled or measured stress acting upon thepart being monitored by AE.Particular emphasis is placed onsensor and system selection,sensor placements,stressingconsiderations,noise reduction/rejection techniques,spatialfiltering,location determination,use of guard sensors,collec-tion of AE data,AE data analysis and report.The purpose ofthe AE examination is to analyze how an object underevaluation is withstanding the applied load.1.3 Possible applications of this guide includes materialscharacterization,quality control of production processes,prooftesting after fabrication,evaluating regions of interest of largerstructures and retesting after intervals of service.The appliedload may include mechanical forces(tension,compression ortorsional)internal pressure and thermal gradients.1.4 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:2E650 Guide for Mounting Piezoelectric Acoustic EmissionSensorsE750 Practice for Characterizing Acoustic Emission Instru-mentationE976 Guide for Determining the Reproducibility ofAcousticEmission Sensor ResponseE1316 Terminology for Nondestructive ExaminationsE2374 Guide for Acoustic Emission System PerformanceVerification3.Terminology3.1 Definitions:3.1.1 Terminology related to acoustic emission is defined inTerminology E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 applied loada controlled or known force or stresswhich is applied to an object under examination for the purposeof analyzing the objects reaction(by means ofAE monitoring)to that stress.3.2.2 guard sensorssensors whose primary function is theelimination of extraneous noise based on arrival sequences.3.2.3 spatial discriminationthe process of using one ormore(guard and data)sensors to eliminate extraneous noisebased on arrival sequences.3.2.4 spatial filteringability of an AE system or analysisto disregard AE activity based on source location of the AEevent.4.Significance and Use4.1 The purpose of theAE examination is to analyze how anexamination object is withstanding the applied load,or if it issuffering from some latent damage.Consequently the emissionactivity must be evaluated in relation to the applied load.4.2 The applied load(on the examination object)mayinclude mechanical forces(tension,compression or torsional),internal pressure and thermal gradients.It may be short to long,random or cyclic.The applied load may be controlled by theexaminer or may already exist as part of the process.In eithercase the applied load is measured along with the AE activity.4.3 Possible applications include the determination of partintegrity,quality control assessment of production processes ona sampled or 100%inspection basis,in-process examinationduring a period of applied load of a fabrication process(forexample,spot welding,bonding,soldering,pressing,etc.),1This guide is under the jurisdiction of ASTM Committee E07 on Nondestruc-tive Testing and is the direct responsibility of Subcommittee E07.04 on AcousticEmission Method.Current edition approved June 15,2012.Published September 2012.Originallyapproved in 1998.Last previous edition approved in 2007 as E1932-07.DOI:10.1520/E1932-12.2For 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.*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 proof-testing after fabrication,monitoring a“region of inter-est”(or concern)of a structure(for example,bridge joint orrepair,vessel,pipe),and reexamination after intervals ofservice.5.Procedure5.1 Preliminary Information:5.1.1 Before examination,the following informat