ASTM E1735-2007(2014) Standard Test Method for Determining Relative Image Quality of Industrial Radiographic Film Exposed to X-Radiation from 4 to 25 MeV《曝光于4 MeV至25 MeV的X射线放射的工业放射.pdf

1、Designation: E1735 07 (Reapproved 2014)Standard Test Method forDetermining Relative Image Quality of IndustrialRadiographic Film Exposed to X-Radiation from 4 to 25MeV1This standard is issued under the fixed designation E1735; the number immediately following the designation indicates the year ofori

2、ginal 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.1. Scope1.1 This test method covers determination of the relativeimage qua

3、lity response of 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 particularproce

4、ssing system and 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 a

5、ndare capable of 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 informati

6、on only.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 and determine the applica-bility of regulatory limitations prior to use.2. Refe

7、renced Documents2.1 ASTM Standards:2E999 Guide for Controlling the Quality of Industrial Radio-graphic Film ProcessingE1025 Practice for Design, Manufacture, and MaterialGrouping Classification of Hole-Type Image Quality In-dicators (IQI) Used for RadiologyE1079 Practice for Calibration of Transmiss

8、ion Densitom-etersE1316 Terminology for Nondestructive ExaminationsE1815 Test Method for Classification of Film Systems forIndustrial Radiography3. Terminology3.1 DefinitionsDefinitions of terms relating to gamma andX-radiology are found in Terminology E1316.4. Significance and Use4.1 This test meth

9、od provides 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 constan

10、t, the image 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.) steelabs

11、orber with 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.

12、). The surface 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 befabricated s

13、eparately 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 maximum of 6.3-m(250-in.) Raground finish.1This test method is under the jurisdict

14、ion of ASTM Committee E07 onNondestructive Testing and is the direct responsibility of Subcommittee E07.01 onRadiology (X and Gamma) Method.Current edition approved June 1, 2014. Published July 2014. Originally approvedin 1995. Last previous edition approved in 2007 as E1735 - 07. DOI: 10.1520/E1735

15、-07R14.2For 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.Copyright ASTM International, 100 Barr Harbor Drive, P

16、O Box C700, West Conshohocken, PA 19428-2959. United States16. Radiation Source6.1 The source of radiation shall be an X-ray generatorcapable 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 ca

17、ssette or a flexible film holder with a vacuum ormechanical means for providing good film-screen contact.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 = 1

18、2.5 6 0.1 mm (0.492 6 0.004 in.); other dimensions in accordance with standard engineeringpractice.Plaque Letter Plaque Thickness Hole Set Hole Diametermm (in.) mm (in.)A 1.6 0.025 (0.0625 0.001) 1 3.0 0.025 (0.118 0.001)B 1.3 0.025 (0.050 0.001) 2 1.8 0.025 (0.072 0.001)C 0.97 0.025 (0.038 0.001) 3

19、 1.8 0.025 (0.072 0.001)D 0.64 0.025 (0.025 0.001) 4 1.5 0.025 (0.060 0.001)5 1.5 0.025 (0.060 0.001)6 1.22 0.025 (0.048 0.001)7 1.42 0.025 (0.056 0.001)8 1.17 0.025 (0.046 0.001)9 0.94 0.025 (0.037 0.001)FIG. 1 Image Quality IndicatorE1735 07 (2014)27.2 ScreensLead foil screens with a front thickne

20、ss 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 Procedure8.1 Source

21、 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 Relationship an

22、d 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 IdentificationIdentif

23、y 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 theimages of the holes in the IQI. Note that the letters andnumbers will be magnified when placed on the source side ofthe absorber.Organization: _ Date: _Film an

24、d Exposure DataFilm Type _ Reader _Megavoltage _ X-Ray Source _Intrinsic, built-infilter material _Intrinsic filterthickness _Added filter material _ Added filterthickness _Source to Film Distance _ Focal SpotSize _mA-S/RADS _Screens (Material) _ Thickness: Front _Back _ProcessingAutomatic Manual Dr

25、yProcessor BrandType _Developer BrandType _DeveloperBrandType _ProcessorBrandType _Temp. _ Temp. _ Temp. _Time _ Time _ Time _ReplenishmentRate _ Seasoning: auto. _ manual_dry _InterpretationIQI PlaqueThickness (T)HoleDia. (D)Index(T)(D)Number of Visible Holesmm in. mm in. mm2in.2Expos. Expos. Expos

26、. 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 _ _ _ _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

27、 0.60 0.009 _ _ _ _FIG. 2 Data Sheet for Evaluating the Image Quality Response of Radiographic Film (4 to 25 MeV)E1735 07 (2014)38.4 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 with Practic

28、eE1079. 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 used, in accord

29、ance with GuideE999 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, that is, leadin

30、g 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, process aminimum o

31、f 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 record on the d

32、atasheet 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 in.)/gal ofdev

33、eloper. 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 processing pro

34、cedures. 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 type should be

35、 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 3 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 given size (ho

36、le 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 filmtype.9.2.1

37、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. 2.9.3 First Alt

38、ernate (Optional) Method of EvaluationEachhole set is converted to equivalent image quality sensitivity(EPS), as prescribed in the Appendix of Practice E1025. Plotthe number of visible holes after averaging versus the EPSvalues for each hole set. This gives a set of points on a graphthrough which a

39、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) Method of Eval

40、uation: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 use of the fol

41、lowingformula:C 5 Qb115 2 Nb!Qa2 Qb!Na2 Nb(1)where:C = classification index (the midpoint or 50 % point on thegraph in 9.3),Na= total number of visible holes in the hole set immedi-ately above the midpoint, and Qa= corresponding EPSvalue, and3Half-flashed implies that one half the total film area of

42、 each film is exposed tothe white light source prior to development.TABLE 1 Average Number of Visible HolesNOTE 1This table specifies the film type for given exposure condi-tions corresponding to Fig. 2, which characterizes a film system (see alsoTest Method E1815).FilmType123456789VisibilityIndexa

43、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 77.2E1735 07 (2014)4Nb= total number of visible holes in the hole set immedi-ately below the midpoint, and Qb= corresponding EPSvalue.9.4.2 The following example is given for

44、 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 1.49115 2 12!1.57 2 1.49!23 2 12(2)C 5 1.5110. Precision and Bias10.1 No statement is made about the pre

45、cision 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 validity of

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