1、Designation: E 1936 03Standard Reference Radiograph forEvaluating the Performance of Radiographic DigitizationSystems1This standard is issued under the fixed designation E 1936; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This reference radiograph covers a series of test targetssuitable for evaluating, quantifying, and documenting
3、 perfor-mance parameters of the radiographic digitization process orthe electronic image reconstruction process, or both. Thisreference radiograph can be used for visual and electronicanalysis of digitization systems. This is the first of three relatedstandards. Subsequent standards will provide gui
4、dance on theuse of the test targets and recommended system performancelevels1.2 This reference radiograph provides a series of testtargets to provide a vehicle for the evaluation of spatialresolution, density contrast sensitivity, dynamic range, andspatial linearity as well as other aspects of a dig
5、itizationsystem. The test targets are suitable for evaluating a digitiza-tion system with a spatial resolution down to ;1/1000 in. 25micrometres () a density contrast sensitivity down to 0.02optical density (OD), a density range of 0.5 to 4.5 OD, and afilm size capacity of 14 in. 355 mm wide by 17 i
6、n. 431 mmlong.1.3 The values stated in inch-pound units are to be regardedas the standard, with the exception of the spatial resolutiontargets (6.2 and 6.7) which are stated in SI units.1.4 This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the respo
7、nsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:E 1079 Practice for Calibration of Transmission Densitom-eters2E 1254 Guide for Storage of Radiogr
8、aphs and UnexposedIndustrial Radiographic Films2E 1316 Terminology for Nondestructive Examinations2E 1411 Practice for Qualification of Radioscopic Systems22.2 ASME Standard:Section V,Article 2, MandatoryAppendix VI, Digital ImageAcquisition, Display, Interpretation and Storage forNuclear Applicatio
9、ns32.3 ASTM Adjuncts:Standard Reference Radiograph for Evaluating the Perfor-mance of Radiographic Digitization Systems43. Terminology3.1 Definitions:3.1.1 Refer to Terminology E 1316 for definitions of termsused in this guide.3.2 Definitions of Terms Specific to This Standard:3.2.1 converging line
10、pairsthe targets located on thereference radiograph that are used to determine the spatialresolution of the digitization system.3.2.2 parallel line pairsthe targets located on the refer-ence radiograph that are used in conjunction with the converg-ing line pairs to determine the spatial resolution o
11、f thedigitization system.3.2.3 reference radiographthe single piece of industrialradiographic film containing all of the reference targets de-scribed in this document.3.2.4 scan lineit is a path that is one pixel high (vertical)by the number of pixels wide (horizontal), that is captured bythe digiti
12、zation system. The scan lines are added, one on top ofthe other, to electronically reproduce the physical (analog) datain the horizontal (film width) and vertical (film length) direc-tions on the display monitor.3.2.5 spatial linearitythe accuracy to which a digitizationsystem reproduces the physica
13、l dimension. It is assessed withina single scan line and from one scan line to the next (horizontaland vertical directions).1This reference radiograph is under the jurisdiction ofASTM Committee E07 onNondestructive Testing and is the direct responsibility of Subcommittee E07.02 onReference Radiologi
14、cal Images.Current edition approved July 10, 2003. Published September 2003. Originallyapproved in 1997. Last previous edition approved in 1997 as E 1936 - 97.2Annual Book of ASTM Standards, Vol 03.03.3Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Th
15、ree Park Ave., New York, NY 10016-5990.4Available from EPRI NDE Center, NDE Division, 1300 Harris Blvd., Charlotte,NC 28262.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.6 spatial resolutionit is measured as the minimumdistance
16、 detectable between two physically spaced lines (see6.2 spatial resolution targets). It is determined by the samplingrate in physical two-dimensional space and the system un-sharpness.3.2.7 targetsthe physical patterns on the reference radio-graph that are used to evaluate the radiographic film digi
17、tiza-tion system.4. Significance and Use4.1 This reference radiograph may be used to quantify theperformance characteristics of a radiographic digitization sys-tem or to provide periodic evaluations of a digitization systemin a production mode to verify that appropriate operatingcharacteristics are
18、being maintained. This reference radiographprovides a means for verifying the performance of a digitiza-tion system in much the same way that the tests described inPractice E 1411, provide for the verification of a radioscopicimaging system. It may be used to evaluate the performance ofa digitizatio
19、n system in accordance with the requirementscontained in ASME Section V, Article 2, Mandatory AppendixVI, or other documents invoking requirements of this referenceradiograph.4.2 This reference radiograph provides a tool that allows theuser to determine the performance of their radiographic digi-tiz
20、ation system. This reference radiograph may be used, wherethere is no other applicable document, for establishing recordsof quality and acceptable levels of performance between thecognizant engineering organization and purchaser of inspectedcomponents. This reference radiograph does not provide guid
21、-ance on use of the test targets or recommend system perfor-mance levels.5. Preparation of Reference Radiograph5.1 The optical densities specified in 6.3 and 6.4 of thisdocument are ascertained using densitometry equipment andtechniques in accordance with Practice E 1079, and are sup-plied with the
22、adjunct reference radiograph. Optical densitiesare recorded in the center 0.12 in. 3 mm of each of the densitytargets in 6.3 and 6.4.5.2 Film DeteriorationRadiographic film is subject towear and tear from handling and use. The extent to which theimage deteriorates over time is a function of storage
23、condi-tions, care in handling, and amount of use. Reference radio-graphic film is no exception and may exhibit a loss of imagequality over time. The reference radiograph should therefore beexamined each time it is used for signs of wear and tear,including scratches, abrasions, stains, and so forth.
24、A referenceradiograph that shows signs of excessive wear and tear, whichcould influence the interpretation and use of the referenceradiograph, should be replaced. A guide for the storage of thereference radiograph is described in Guide E 1254.6. Description of Targets6.1 The reference radiograph has
25、 five types of targets thatmay be used to evaluate various parameters of the digitizationsystem. The targets are located within a background density of 3.0 OD. The reference radiograph is divided into three areaswith sizes of 8 in. 203 mm by 10 in. 254 mm, 11 in. 279mm by 14 in. 355 mm, and 14 in. 3
26、55 mm by 17 in. 430mm. These have been created for digitization systems unableto accommodate film sizes up to 14 in. by 17 in. The referenceradiograph may be cut to custom fit a particular digitizationsystem and still contain all of the necessary targets within eachof these areas that are represente
27、d on the illustration in Fig. 1.6.2 Spatial Resolution TargetsThese consist of three iden-tical groups of at least 6 converging line pairs. The targets havea maximum resolution of no less than 20 line pairs permillimetre (lp/mm) and a minimum resolution of no greaterthan 1 lp/mm. The three line pair
28、 groups are oriented in the 0,45, and 90 positions. The maximum resolution is orientedtoward the corners of the reference radiograph, Referencemarks are provided to indicate spatial resolution at levels of 1,2, 3, 4, 5, 6, 7, 8, 9, 10, 15, and 20 lp/mm.6.3 Density Contrast Sensitivity TargetsThese c
29、onsist of0.4 in. 1 cm by 0.4 in. fields centered in 1.6 in. 4 cm by 1.6in. blocks of a slightly lower density. Two series of blocks willbe used, one block series with an optical density of 2.00 ODon a background of 1.95 OD, an optical density change of0.05. The second block series will have 3.50 OD
30、on abackground of 3.40 OD, an optical density change of 0.10.The relative density change is more important than the absolutedensity. These 2 block series are grouped in no less than sixareas on the reference radiograph.6.4 Stepped Density TargetsThese targets are to be used todetermine dynamic range
31、 and density contrast sensitivity. Theyshall consist of a series of 0.4 in. 1 cm by 0.4 in. blocks withdensities of 0.5 to 4.5 OD. There shall be no less than 13 blocksaligned in a row with the following approximate densities: 4.5,4.02, 4, 3.5, 3.02, 3, 2.5, 2.02, 2, 1.5, 1.02, 1, and 0.5 OD.These b
32、locks are grouped in no less than eight areas on thereference radiograph.6.5 Sharp Edge TargetEach stepped density target (cor-responding to 6.4) with the density 0.5 OD shall have sharpedges to the background of 3.0 OD. The unsharpness of thesharp edges shall be less than 10 micron 0.0004 in. Thiss
33、harp edge shall be used to measure horizontal and vertical linespread functions by differentiation of step profiles. The nor-malized magnitude of the Fourier transform of a line spreadfunction yields the Modulation Transfer Function (MTF).6.6 Linearity TargetsThese targets provide 1.0 in. 25.4mm uni
34、ts of measure. They shall be located in the horizontalas well as the vertical directions. The linearity targets, ormeasurement scale, divides the reference radiograph into threedistinct film sizes 8 by 10 in. 203 by 254 mm, 11 by 14 in.279 by 355 mm, and 14 by 17 in. 355 by 430 mm.6.7 Parallel Line
35、Pair TargetThis target consists of aparallel line pair gage with a resolution starting at no greaterthan 0.5 lp/mm and increases to a resolution of no less than 20lp/mm. This target may be used to determine spatial resolution.It is positioned near the center of the 8 by 10 in. 203 by 254mm area on t
36、he reference radiograph.6.8 Additional targets may be located on the referenceradiograph as long as they do not interfere with the digitization,or interpretation, of the targets located in 6.2 through 6.7.E1936032FIG. 1 Representation of the AdjunctE19360337. Keywords7.1 density contrast sensitivity
37、; digitization; line pairs; ref-erence radiograph; spatial linearity; spatial resolution; systemevaluation; target; X-rayASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expres
38、sly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised,
39、 either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may at
40、tend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).E1936034
