ASTM_E_1570_-_11.pdf

Designation:E157011Standard Practice forComputed Tomographic(CT)Examination1This standard is issued under the fixed designation E1570;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope*1.1 This practice is for computed tomography(CT),whichmay be used to nondestructively disclose physical features oranomalies within a test object by providing radiological densityand geometric measurements.This practice implicitly assumesthe use of penetrating radiation,specifically X-ray and-ray.1.2 CT systems utilize a set of transmission measurementsmade along paths through the test object from many differentdirections.Each of the transmission measurements is digitizedand stored in a computer,where they are subsequently recon-structed by one of a variety of techniques.A treatment of CTprinciples is given in Guide E1441.1.3 CT is broadly applicable to any material or test objectthrough which a beam of penetrating radiation passes.Theprincipal advantage of CT is that it provides densitometric(thatis,radiological density and geometry)images of thin crosssections through an object without the structural superpositionin projection radiography.1.4 This practice describes procedures for performing CTexaminations.This practice is to address the general use of CTtechnology and thereby facilitate its use.1.5 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.For specific safetystatements,see Section 8,NBS Handbook 114,and FederalStandards 21 CFR 1020.40 and 29 CFR 1910.96.2.Referenced Documents2.1 ASTM Standards:2E1316 Terminology for Nondestructive ExaminationsE1441 Guide for Computed Tomography(CT)ImagingE1695 Test Method for Measurement of Computed Tomog-raphy(CT)System Performance2.2 NIST Standard:ANSI N43.3 General Radiation Safety Installations UsingNon-Medical X-Ray and Sealed Gamma Sources up to 10MeV32.3 Federal Standards:421 CFR 1020.40 Safety Requirements of Cabinet X RaySystems29 CFR 1910.96 Ionizing Radiation2.4 ASNT Documents:5SNT-TC-1A Recommended Practice for Personnel Qualifi-cation and Certification in Nondestructive TestingANSI/ASNT-CP-189 Qualification and Certification of Non-destructive Testing Personnel2.5 Military Standard:MIL-STD-410 Nondestructive Testing Personnel Qualifica-tion and Certification42.6 AIA Standard:NAS-410 Certification and Qualification of NondestructiveTesting Personnel63.Terminology3.1 DefinitionsFor definitions of terms used in this guide,refer to Terminology E1316 and Annex A1 in Guide E1441.4.Summary of Practice4.1 Requirements in this practice are intended to control thereliability and quality of the CT images.4.2 CT systems are made up of a number of subsystems;thefunction served by each subsystem is common in almost all CTscanners.Section 7 describes the following subsystems:1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.01 onRadiology(X and Gamma)Method.Current edition approved July 1,2011.Published July 2011.Originally approvedin 1993.Last previous edition approved in 2005 as E1570-00(2005)1.DOI:10.1520/E1570-11.2For 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 from National Institute of Standards and Technology(NIST),100Bureau Dr.,Stop 1070,Gaithersburg,MD 20899-1070,http:/www.nist.gov.4Available from Standardization Documents Order Desk,DODSSP,Bldg.4,SectionD,700RobbinsAve.,Philadelphia,PA19111-5098,http:/dodssp.daps.dla.mil.5Available fromAmerican Society for Nondestructive Testing(ASNT),P.O.Box28518,1711 Arlingate Ln.,Columbus,OH 43228-0518,http:/www.asnt.org.6Available 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 4.2.1 Source of penetrating radiation,4.2.2 Radiation detector or an array of detectors,4.2.3 Mechanical scanning assembly,and4.2.4 Computer system including:4.2.4.1 Image reconstruction software/hardware,4.2.4.2 Image display/analysis system,4.2.4.3 Data storage system,and4.2.4.4 Operator interface.4.3 Section 8 describes and defines the procedures forestablishing an