ASTM E1255-2009 Standard Practice for Radioscopy《放射线透视的标准实施规程》.pdf

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1、Designation: E 1255 09Standard Practice forRadioscopy1This standard is issued under the fixed designation E 1255; 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

2、 of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice2provides application details for radio-scopic examination using penetrating radiation. This includesdynamic radioscopy and for the purposes of this practice,radi

3、oscopy where there is no motion of the object duringexposure (referred to as static radioscopic imaging) both usingan analog component such as an electro-optic device or analogcamera. Since the techniques involved and the applications forradioscopic examination are diverse, this practice is not in-t

4、ended to be limiting or restrictive, but rather to address thegeneral applications of the technology and thereby facilitate itsuse. Refer to Guides E94and E 1000, Terminology E 1316,Practice E 747, Practice E 1025, Test Method E 2597, and Fed.Std. Nos. 21 CFR 1020.40 and 29 CFR 1910.96 for a list of

5、documents that provide additional information and guidance.1.2 The general principles discussed in this practice applybroadly to penetrating radiation radioscopic systems. However,this document is written specifically for use with X-ray andgamma-ray systems. Other radioscopic systems, such as thosee

6、mploying neutrons, will involve equipment and applicationdetails unique to such systems.1.3 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

7、 and determine the applica-bility of regulatory limitations prior to use. For specific safetystatements, see Section 8 and Fed. Std. Nos. 21 CFR 1020.40and 29 CFR 1910.96.2. Referenced Documents2.1 ASTM Standards:3E94 Guide for Radiographic ExaminationE 543 Specification for Agencies Performing Nond

8、estruc-tive TestingE 747 Practice for Design, Manufacture and MaterialGrouping Classification of Wire Image Quality Indicators(IQI) Used for RadiologyE 1000 Guide for RadioscopyE 1025 Practice for Design, Manufacture, and MaterialGrouping Classification of Hole-Type Image Quality Indi-cators (IQI) U

9、sed for RadiologyE 1316 Terminology for Nondestructive ExaminationsE 1411 Practice for Qualification of Radioscopic SystemsE 1742 Practice for Radiographic ExaminationE 2002 Practice for Determining Total Image Unsharpnessin RadiologyE 2597 Practice for Manufacturing Characterization ofDigital Detec

10、tor Arrays2.2 ASNT Standard:4SNT-TC-1A Recommended Practice for Personnel Qualifi-cation and Certification in Nondestructive TestingANSI/ASNT CP-189 Standard for Qualification and Certi-fication of Nondestructive Testing Personnel2.3 Federal Standards:521 CFR 1020.40 Safety Requirements of Cabinet X

11、-RaySystems29 CFR 1910.96 Ionizing Radiation2.4 National Council on Radiation Protection and Mea-surement (NCRP) Standard:NCRP 49 Structural Shielding Design and Evaluation forMedical Use of X Rays and Gamma Rays of Energies Upto 10 MeV62.5 AIA Standard:NAS-410 NAS Certification and Qualification of

12、 Nonde-structive Test Personnel73. Summary of Practice3.1 Visual evaluation as well as computer-aided automatedradioscopic examination systems are used in a wide variety ofpenetrating radiation examination applications.Asimple visual1This practice is under the jurisdiction of ASTM Committee E07 on N

13、onde-structive Testing and is the direct responsibility of Subcommittee E07.01 onRadiology (X and Gamma) Method.Current edition approved July 1, 2009. Published August 2009. Originallyapproved in 1988. Last previous edition approved in 2002 as E 1255 - 96(2002).2For ASME Boiler and Pressure Vessel C

14、ode applications see related PracticeSE-1255 in Section II of that code.3For 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 AS

15、TM website.4Available fromAmerican Society for NondestructiveTesting (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:/www.asnt.org.5Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/www.dodssp

16、.daps.mil.6Available from NCRP Publications, 7010 Woodmont Ave., Suite 1016, Be-thesda, MD 20814.7Available from Aerospace Industries Association of America, Inc. (AIA), 1000Wilson Blvd., Suite 1700,Arlington,VA22209-3928, http:/www.aia-aerospace.org.1Copyright ASTM International, 100 Barr Harbor Dr

17、ive, PO Box C700, West Conshohocken, PA 19428-2959, United States.evaluation radioscopic examination system might consist of aradiation source, a fluorescent screen viewed with an analogcamera, suitably enclosed in a radiation protective enclosureand a video display.At the other extreme, a complex a

18、utomatedradioscopic examination system might consist of an X-raysource, a robotic examination part manipulator, a radiationprotective enclosure, an electronic image detection system witha camera, a frame grabber, a digital image processor, an imagedisplay, and a digital image archiving system. All s

19、ystemcomponents are supervised by the host computer, whichincorporates the software necessary to not only operate thesystem components, but to make accept/reject decisions aswell. Systems having a wide range of capabilities betweenthese extremes can be assembled using available components.Guide E 10

20、00 lists many different system configurations.3.2 This practice provides details for applying radioscopicexamination with camera techniques; however, supplementalrequirements are necessary to address areas that are applicationand performance specific. Annex A1 provides the detailedsupplemental requi

21、rements for government contracts.4. Significance and Use4.1 As with conventional radiography, radioscopic exami-nation is broadly applicable to any material or examinationobject through which a beam of penetrating radiation may bepassed and detected including metals, plastics, ceramics, com-posites,

22、 and other nonmetallic materials. In addition to thebenefits normally associated with radiography, radioscopicexamination may be either a dynamic, filmless techniqueallowing the examination part to be manipulated and imagingparameters optimized while the object is undergoing examina-tion, or a stati

23、c, filmless technique wherein the examinationpart is stationary with respect to the X-ray beam. The differ-entiation to systems with digital detector arrays (DDAs) is theuse of an analog component such as an electro-optic device oran analog camera. Recent technology advances in the area ofprojection

24、 imaging, camera techniques, and digital imageprocessing provide acceptable sensitivity for a wide range ofapplications. If normal video rates are not adequate to detectfeatures of interest then averaging techniques with no move-ment of the test object shall be used.5. Equipment and Procedure5.1 Sys

25、tem ConfigurationMany different radioscopic ex-amination systems configurations are possible, and it is impor-tant to understand the advantages and limitations of each. It isimportant that the optimum radioscopic examination system beselected for each examination requirement through a carefulanalysi

26、s of the benefits and limitations of the available systemcomponents and the chosen system configuration. The provideras well as the user of the radioscopic examination servicesshould be fully aware of the capabilities and limitations of theradioscopic examination system that is proposed for examina-

27、tion of the object. The provider and the user of radioscopicexamination services shall agree upon the system configurationto be used for each radioscopic examination application underconsideration, and how its performance is to be evaluated.5.1.1 The minimum radioscopic examination system con-figura

28、tion will include an appropriate source of penetratingradiation, a means for positioning the examination objectwithin the radiation beam, in the case of dynamic radioscopy,and a detection system. The detection system may be as simpleas a camera-viewed fluorescent screen with suitable radiationshield

29、ing for personnel protection that meets applicable radia-tion safety codes.5.1.2 A more complex system might include the followingcomponents:5.1.2.1 An Image Intensifier to intensify the photon detec-tion from the fluorescent screen,5.1.2.2 A micro- or mini-focus X-ray tube can be used withhigh magn

30、ification to facilitate higher-resolution projectionimaging,5.1.2.3 A multiple axis examination part manipulation sys-tem to provide dynamic, full volumetric examination partmanipulation under operator manual control or automatedprogram control, for dynamic radioscopy,5.1.2.4 An electronic imaging s

31、ystem to display a bright,two-dimensional gray-scale image of the examination part atthe operators control console,5.1.2.5 Adigital image processing system to perform imageenhancement and image evaluation functions,5.1.2.6 An archival quality image recording or storagesystem, and5.1.2.7 A radiation

32、protective enclosure with appropriatesafety interlocks and a radiation warning system.5.1.3 Whether a simple or a complex system is used, thesystem components and configuration utilized to achieve theprescribed examination results must be carefully selected.5.2 Practice:5.2.1 The purchaser and suppl

33、ier for radioscopic examina-tion services shall mutually agree upon a written procedure andalso consider the following general requirements.5.2.1.1 Equipment QualificationsA listing of the systemfeatures that must be qualified to ensure that the system iscapable of performing the desired radioscopic

34、 examinationtask. System features are described in Guide E 1000.5.2.1.2 Examination Object Scan Plan for DynamicRadioscopyA listing of object orientations, ranges of mo-tions, and manipulation speeds through which the object mustbe manipulated to ensure satisfactory examination.5.2.1.3 Radioscopic P

35、arametersA listing of all the radia-tion source-related variables that can affect the examinationoutcome for the selected system configuration such as: sourceenergy, intensity, focal spot size, filter in the X-ray beam,collimators, range of source to object distances, range of objectto image plane d

36、istances, and source to image plane distances.5.2.1.4 Image Processing ParametersA listing of all theimage processing variables necessary to enhance flaw detect-ability in the object and to achieve the required sensitivitylevel. These would include, but are not limited to, techniquessuch as noise re

37、duction, contrast enhancement, and spatialfiltering. Great care should be exercised in the selection ofdirectional image processing parameters such as spatial filter-ing, which may emphasize features in certain orientations andsuppress them in others. The listing should indicate the meansfor qualify

38、ing image processing parameters.E12550925.2.1.5 Image Display ParametersA listing of the tech-niques and the intervals at which they are to be applied forstandardizing the image display as to brightness, contrast,focus, and linearity.5.2.1.6 Accept-Reject CriteriaA listing of the expectedkinds of ob

39、ject imperfections and the rejection level for each.5.2.1.7 Performance EvaluationA listing of the qualifica-tion tests and the intervals at which they are to be applied toensure that the radioscopic examination system is suitable forits intended purpose.5.2.1.8 Image Archiving RequirementsA listing

40、 of therequirements, if any, for preserving a historical record of theexamination results. The listing may include examinationimages along with written or electronically recorded alphanu-meric or audio narrative information, or both, sufficient toallow subsequent reevaluation or repetition of the ra

41、dioscopicexamination.5.2.1.9 Personnel QualificationIf specified in the contrac-tual agreement, personnel performing examinations to thisstandard shall be qualified in accordance with a nationally orinternationally recognized NDT personnel qualification prac-tice or standard such as ANSI/ASNT CP-189

42、, SNT-TC-1A,NAS-410, or similar document and certified by the employer orcertifying agency, as applicable. The practice or standard usedand its applicable revision shall be identified in the contractualagreement between the using parties.5.2.1.10 Agency EvaluationIf specified in the contractualagree

43、ment, NDT agencies shall be qualified and evaluated inaccordance with Practice E 543. The applicable revision ofPractice E 543 shall be specified in the contractual agreement.6. Radioscopic Examination System PerformanceConsiderations and Measurement6.1 Factors Affecting System PerformanceTotal radi

44、o-scopic examination system performance is determined by thecombined performance of the system components that includesthe radiation source, manipulation system (for dynamic radios-copy), detection system, information processing system, imagedisplay, automatic evaluation system, and examination reco

45、rdarchiving system.6.1.1 Radiation SourcesWhile the radioscopic examina-tion systems may utilize either radioisotope or X-ray sources,X-radiation is used for most radioscopic examination applica-tions. This is due to the energy spectrum of the X-radiation thatcontains a blend of contrast enhancing l

46、onger wavelengths, aswell as the more penetrating, shorter wavelengths. X-radiationis adjustable in energy and intensity to meet the radioscopicexamination test requirements, and has the added safety featureof discontinued radiation production when switched off. Aradioisotope source has the advantag

47、es of small physical size,portability, simplicity, and uniformity of output.6.1.1.1 X-ray machines produce a more intense X-ray beamemanating from a smaller focal spot than do radioisotopesources. X-ray focal spot sizes range from a few millimetresdown to a few micrometres. Reducing the source size

48、reducesgeometric unsharpness, thereby enhancing detail sensitivity.X-ray sources may offer multiple or variable focal spot sizes.Smaller focal spots produce higher resolution when usinggeometrical magnification and provide reduced X-ray beamintensity, while larger focal spots provide higher X-ray in

49、ten-sity and produce lower resolution. Microfocus X-ray tubes areavailable with focal spots that may be adjusted to as small asa few micrometres in diameter, while still producing an X-raybeam of sufficient intensity so as to be useful for the radio-scopic examination of finely detailed objects.6.1.1.2 Conventional focal spots of 1.0 mm and larger areuseful at low geometric magnification values close to 13.Fractional focal spots ranging from 0.4 mm up to 1.0 mm areuseful at geometric magnifications of up to approximately 23.Minifocus spots in the range from 0.1 mm up t