1、Designation: E 1735 07Standard Test Method forDetermining Relative Image Quality of IndustrialRadiographic Film Exposed to X-Radiation from 4 to 25MeV1This standard is issued under the fixed designation E 1735; the number immediately following the designation indicates the year oforiginal adoption o
2、r, in the case of revision, the year 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 test method covers determination of the relativeimage quality response o
3、f industrial radiographic film whenexposed to X-radiation sources having photon energies from 4to 25 MeV. Evaluation of the film is based on the visibility ofholes in a special image quality indicator (IQI). Since resultsfor a given film type may vary, depending on the particularprocessing system an
4、d processing conditions used, it is essen-tial to state the exposure parameters and achieved density,processing chemistry, processing cycle, and processing tem-perature. For the purposes of this test method, it is assumed thatall components of the X-ray system are operating properly andare capable o
5、f producing a given image quality. This testmethod is not intended to be used for films exposed withCobalt 60 sources or X-ray sources below 4 MeV.1.2 The values stated in either SI or inch-pound units are tobe regarded as the standard. The values given in parenthesesare for information only.1.3 Thi
6、s 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 Document
7、s2.1 ASTM Standards:2E 999 Guide for Controlling the Quality of Industrial Ra-diographic Film ProcessingE 1025 Practice for Design, Manufacture, and MaterialGrouping Classification of Hole-Type Image Quality Indi-cators (IQI) Used for RadiologyE 1079 Practice for Calibration of Transmission Densitom
8、-etersE 1316 Terminology for Nondestructive ExaminationsE 1815 Test Method for Classification of Film Systems forIndustrial Radiography3. Terminology3.1 DefinitionsDefinitions of terms relating to gamma andX-radiology are found in Terminology E 1316.4. Significance and Use4.1 This test method provid
9、es a test for determining therelative image quality response of radiographic film whenexposed to 4 to 25 MeV X rays as any single component of thetotal X-ray system (for example, screens) is varied. By holdingthe technique parameters (except exposure time) and process-ing parameters constant, the im
10、age quality response of radio-graphic film may be evaluated on a relative basis.4.2 Alternately, this test method provides a test for measur-ing the image quality of the X-ray system or any component ofthe system.5. Test Specimen5.1 The test specimen will consist of a 15-cm (6-in.) steelabsorber wit
11、h a special IQI placed on the radiation (source)side of the absorber.5.1.1 AbsorberThe absorber shall be made of carbon steelor Type 300 stainless steel. The thickness of 15 cm (6 in.) canbe achieved by stacking thinner plates whose length and widthshall be at least 20 by 25 cm (8 by 10 in.). The su
12、rface finishof the top and bottom of the absorber shall be a maximum of6.3-m (250-in.) Raground finish.5.1.2 Image Quality IndicatorThe IQI shall be fabricatedof carbon steel or Type 300 stainless steel and shall conform toFig. 1. The IQI steps, identified as Plaques A-D, may be1This test method is
13、under the jurisdiction of ASTM Committee E07 onNondestructive Testing and is the direct responsibility of Subcommittee E07.01 onRadiology (X and Gamma) Method.Current edition approved Feb. 15, 2007. Published March 2007. Originallyapproved in 1995. Last previous edition approved in 2000 as E 1735 -
14、95(2000)e1.2For 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.1Copyright ASTM International, 100 Barr Harbor Dri
15、ve, PO Box C700, West Conshohocken, PA 19428-2959, United States.fabricated separately and then taped together, as shown in Fig.1, using suitable tape to form the array as shown. The tape shallnot cover any of the holes in the IQI. The surface finish of theIQI top and bottom surfaces shall be a maxi
16、mum of 6.3-m(250-in.) Raground finish.NOTE 1All plaques identical except hole size and plaque thickness hole: row spacing tolerance 6 0.1 mm (6 0.004 in.), nonaccumulative DimensionA=106 0.1 mm (0.395 6 0.004 in.) and Dimension B = 12.5 6 0.1 mm (0.492 6 0.004 in.); other dimensions in accordance wi
17、th standard engineeringpractice.Plaque Letter Plaque Thickness Hole Set Hole Diametermm (in.) mm (in.)A1.66 0.025 (0.0625 6 0.001) 1 3.0 6 0.025 (0.118 6 0.001)B136 0.025 (0.050 6 0.001) 2 1.8 6 0.025 (0.072 6 0.001)C 0.97 6 0.025 (0.038 6 0.001) 3 1.8 6 0.025 (0.072 6 0.001)D 0.64 6 0.025 (0.025 6
18、0.001) 4 1.5 6 0.025 (0.060 6 0.001)51.56 0.025 (0.060 6 0.001)6 1.22 6 0.025 (0.048 6 0.001)7 1.42 6 0.025 (0.056 6 0.001)8 1.17 6 0.025 (0.046 6 0.001)9 0.94 6 0.025 (0.037 6 0.001)FIG. 1 Image Quality IndicatorE17350726. Radiation Source6.1 The source of radiation shall be an X-ray generatorcapab
19、le of operating in any part (or all) of the range from 4 to25 MeV.7. Film Holder and Screens7.1 Film HolderThe film holder shall be a medical-type,hard-backed cassette or a flexible film holder with a vacuum ormechanical means for providing good film-screen contact.7.2 ScreensLead foil screens with
20、a front thickness of0.010 to 0.050 in. (0.25 mm to 1.27 mm) and back thickness of0.010 in., minimum, shall be used. Thicker screens may beused at the users discretion, provided that the actual thicknessused is documented on the data sheet (Fig. 2) and agreed uponby all parties concerned.8. Test Proc
21、edure8.1 Source to Film DistanceThe source to film distance isbased on achieving a geometrical unsharpness (Ug) of 0.15 mm(0.006 in.) or less when used with the test specimens describedin Section 5. The minimum source to film distance to be usedshall be 1 m (39.4 in.).8.2 Film/Test Specimen: Source
22、Relationship and FilmPlacementThe plane of the film and test specimen shall benormal to the central ray of the radiation source. Collimate thesource so as to limit the radiation source to the film. Place thefilm holder/cassette opposite the source side and in contactwith the absorber.8.3 Film Identi
23、ficationIdentify the film number andsource energy used by means of lead numbers and lettersplaced on the corner of the plate so as not to interfere with theOrganization: _ Date: _Film and Exposure DataFilm Type _ Reader _Megavoltage _ X-Ray Source _Intrinsic, built-infilter material _Intrinsic filte
24、rthickness _Added filter material _ Added filterthickness _Source to Film Distance _ Focal SpotSize _mA-S/RADS _Screens (Material) _ Thickness: Front _ Back _ProcessingAutomatic Manual DryProcessor BrandType _Developer BrandType _DeveloperBrandType _ProcessorBrandType _Temp. _ Temp. _ Temp. _Time _
25、Time _ Time _ReplenishmentRate _ Seasoning: auto. _ manual _ dry _InterpretationIQI PlaqueThickness (T)HoleDia. (D)Index(T)3(D)Number of Visible Holesmm in. mm in. mm2in.2Expos. Expos. Expos. Avg.1.60 0.063 3.00 0.118 4.80 0.0074 _ _ _ _1.80 0.072 2.88 0.0045 _ _ _ _1.30 0.050 1.80 0.072 2.34 0.0036
26、 _ _ _ _1.50 0.060 1.95 0.0030 _ _ _ _0.97 0.038 1.50 0.060 1.43 0.0023 _ _ _ _1.22 0.048 1.16 0.0018 _ _ _ _0.64 0.025 1.42 0.056 0.91 0.0016 _ _ _ _1.17 0.046 0.75 0.0012 _ _ _ _0.94 0.037 0.60 0.009 _ _ _ _FIG. 2 Data Sheet for Evaluating the Image Quality Response of Radiographic Film (4 to 25 M
27、eV)E1735073images of the holes in the IQI. Note that the letters andnumbers will be magnified when placed on the source side ofthe absorber.8.4 ExposureAdjust the exposure time to provide a filmdensity of 2.00 6 0.1 in the center of the film, as measuredwith a densitometer calibrated in accordance w
28、ith PracticeE 1079. Make three exposures using the same film holder/cassette in accordance with 7.1.8.5 Film ProcessingIn order to minimize any effectscaused by the latent image instability, process the exposed filmnot more than 4 hours after exposure. Either manual orautomatic processing may be use
29、d, in accordance with GuideE 999 and as follows:8.5.1 Automatic ProcessingUse industrial X-ray film au-tomatic processing solutions. Maintain a record on the datasheet of the following:8.5.1.1 The brand name and type of processor;8.5.1.2 The length of time (61 s) that the film is in thedeveloper, th
30、at is, leading edge in to leading edge out;8.5.1.3 The brand name of the processing chemicals, includ-ing the starter, processing temperature to within 0.5C, andreplenishment rate; and8.5.1.4 The total quantity of film used in seasoning freshdeveloper solutions. With fresh developer solutions, proce
31、ss aminimum of ten films (360 by 430 mm (14 by 17 in.)/gal ofdeveloper. Each film should be half-flashed3to a density of 4.0or greater using white light or, alternatively, fully flash alter-nate sheets.8.5.2 Manual ProcessingUse industrial X-ray film pro-cessing solutions in the tests. Maintain a re
32、cord on the datasheet of the following:8.5.2.1 The time of development (6 2 s);8.5.2.2 The temperature of the developer within 0.5C;8.5.2.3 The total quantity of films used in seasoning freshdeveloper solutions. With fresh developer solutions, process aminimum of ten films (360 by 430 mm (14 by 17 i
33、n.)/gal ofdeveloper. Each film should be half-flashed3to a density of 4.0or greater using white light or, alternatively, fully flash alter-nate sheets;8.5.2.4 The replenishment system used; and8.5.2.5 The brand name of the processing chemicals.8.5.3 Dry ProcessingUse the manufacturers recom-mended p
34、rocessing procedures. Maintain a record on the datasheet of the following:8.5.3.1 The brand name of the processor; and8.5.3.2 The length of time that the film is in the processor,that is, leading edge in to leading edge out.9. Data Collection and Evaluation9.1 The three test films for any one film t
35、ype should be readindependently by three readers. Each reader shall record thenumber of holes of a given size visible at each step of the IQI.A magnifier up to 33 is permitted for viewing the film. Asample data sheet is shown in Fig. 2.9.2 The data are evaluated by averaging the number of holesof a
36、given size (hole set) visible on each plaque image of theIQI for each film type. This average is based on the evaluationof three readers of three radiographs for each film type. Thisaveraging procedure is repeated for each film type and is ameasure of the relative image quality response of a given f
37、ilmtype.9.2.1 The relative image quality response for different filmtypes is illustrated in Table 1. The visibility index shown inTable 1 is the sum of the total number of holes detected and canbe used as a measure of image quality under the conditionsemployed and tabulated in accordance with Fig. 2
38、.9.3 First Alternate (Optional) Method of EvaluationEachhole set is converted to equivalent image quality sensitivity(EPS), as prescribed in the Appendix of Practice E 1025. Plotthe number of visible holes after averaging versus the EPSvalues for each hole set. This gives a set of points on a grapht
39、hrough which a continuous smooth curve is drawn. The imagequality response is determined at the point where 50 % of theholes are visible. This value is the classification index for thefilm under testing. Fig. 3 is an idealized illustration of thiscurve plotting method.9.4 Second Alternate (Optional)
40、 Method of Evaluation:9.4.1 In addition to the two methods previously described,the classification index may be calculated mathematicallybetween two adjacent hole sets by interpolating between theEPS values of the hole set with more than 15 visible holes andthe set with less than 15 visible holes by
41、 use of the followingformula:3Half-flashed implies that one half the total film area of each film is exposed tothe white light source prior to development.TABLE 1 Average Number of Visible HolesNOTEThis table specifies the film type for given exposure conditionscorresponding to Fig. 2, which charact
42、erizes a film system (see also TestMethod E 1815).FilmType123456 789VisibilityIndexa 30 30 30 23 12.7 0 0 0 0 125.7b 30 27.7 25.2 12.2 0 0 0 0 0 95.1c 30 26.5 21.7 8.7 0 0 0 0 0 86.9d 30 25.2 15.7 5.3 1 0 0 0 0 77.2E1735074C 5 Qb115 2 Nb!Qa2 Qb!Na2 Nb(1)where:C = classification index (the midpoint o
43、r 50 % point onthe graph in 9.3),Na= total number of visible holes in the hole set immedi-ately above the midpoint, and Qa= correspondingEPS value, andNb= total number of visible holes in the hole set immedi-ately below the midpoint, and Qb= correspondingEPS value.9.4.2 The following example is give
44、n for illustration. A sethaving 23 visible holes has an EPS value of 1.57. An adjacentset has 12 visible holes and an EPS value of 1.49. Insertingthese values into the formula yields the following:C 5 1.49 115 2 12! 1.57 2 1.49!23 2 12(2)C 5 1.5110. Precision and Bias10.1 No statement is made about
45、the precision and bias forindicating the quality of radiographs since the results statemerely whether there is conformance to the criteria for successspecified in this test method.11. Keywords11.1 EPS; film; IQI; radiation; radiographic; X-rayASTM International takes no position respecting the valid
46、ity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly 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 subje
47、ct to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquart
48、ers. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. 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,U
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