1、Designation:E200310(Reapproved 2014)Standard Practice forFabrication of the Neutron Radiographic Beam PurityIndicators1This standard is issued under the fixed designation E2003;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year
2、 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.Scope1.1 This practice covers the material and fabrication of aBeam Purity Indicator(BPI),which can be used to determinethe rela
3、tive quality of radiographic images produced by direct,thermal neutron radiographic examination.1.2 The values stated in SI units are regarded to be standard.1.3 This standard does not purport to address the safetyconcerns,if any,associated with its use.It is the responsibilityof the user of this st
4、andard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E543 Specification for Agencies Performing NondestructiveTestingE545 Test Method for Determining Image Quality in DirectThermal N
5、eutron Radiographic ExaminationE748 Practices for Thermal Neutron Radiography of Mate-rialsE1316 Terminology for Nondestructive Examinations3.Terminology3.1 Definitions For definitions of terms used in thispractice,see Terminology E1316,Section H.4.Summary of Practice4.1 The BPI is used for quantita
6、tive determination ofthermal neutron radiographic quality.It consists of a polytet-rafluoroethylene block containing two boron nitride disks,twolead disks and two cadmium wires.A key feature of the deviceis the ability to make visual analysis of its image for subjectivequality information.Densitomet
7、ric measurements of the imageof the device permit quantitative determination of radiographiccontrast,low-energy photon contribution,pair productioncontribution,image unsharpness,and information regardingfilm and processing quality.4.2 Neutron radiography practices are discussed in PracticeE748.5.Sig
8、nificance and Use5.1 The BPI is designed to yield quantitative informationconcerning neutron beam and image system parameters thatcontribute to film exposure and,thereby,affect overall imagequality.For proper measurements of film exposure due to theneutron beam constituents,the BPI must be fabricate
9、d inaccordance with this practice.5.2 This practice shall be followed for the fabrication of allBeam Purity Indicators to be used with Method E545 todetermine image quality in direct thermal neutron radiography.6.Basis of Application6.1 Qualification of Nondestructive AgenciesIf specifiedin the cont
10、ractual agreement,NDT agencies shall be qualifiedand evaluated as described in Practice E543.The applicablerevision of Practice E543 shall be specified in the contractualagreement.6.2 Procedures and TechniquesThe procedures and tech-niques to be utilized shall be as described in this practice unless
11、otherwise specified.Specific techniques may be specified in thecontractual agreement.6.3 Reporting Criteria/Acceptance CriteriaReporting cri-teria for the examination results shall be in accordance withSections 9 and 10 unless otherwise specified.Acceptancecriteria,for example,for reference radiogra
12、phs,shall bespecified in the contractual agreement.6.4 ReexaminationofRepaired/ReworkedItemsReexamination of repaired/reworked items is not addressed inthis practice and,if required,shall be specified in the contrac-tual agreement.7.Beam Purity Indicator(BPI)7.1 The BPI shall be constructed of polyt
13、etrafluoroethylene,cadmium,lead,and boron nitride.1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.05 onRadiology(Neutron)Method.Current edition approved Oct.1,2014.Published November 2014.Originallyapprove
14、d in 1998.Last previous edition approved in 2010 as E2003-10.DOI:10.1520/E2003-10R14.2For 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
15、onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.2 The construction and dimensions shall be as shown inFig.1.7.3 The BPI may be encased in a frame for easy mounting,but shall not be enclosed in a dust cover nor shall a
16、ny materialcover either side of the BPI face.7.4 Cadmium and lead shall be at least 99.9%pure elemen-tal material.7.5 Boron nitride shall be hot-pressed,minimum 40%elemental boron.7.6 The polytetrafluoroethylene block tolerances shall be610%.7.7 The tolerances for the holes and the grooves shall besuch that the disks and the wires do not fall out during use.8.Fabrication8.1 Individual Components:8.1.1 Form the polytetrafluoroethylene base by milling an8-mm thick sheet of the material into a 25-m
