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1、BRITISH STANDARD BS ISO 7004:1987 Implementation of ISO 7004:1987 Photography Industrial radiographic film Determination of ISO speed and average gradient when exposed to X- and - radiation UDC 771.531.37:778.83:771.534.5 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:36:29 GMT+00:00 2006
2、, Uncontrolled Copy, (c) BSI BS ISO 7004:1987 This British Standard, having been prepared under the direction of the Consumer Products and Services Sector Board, was published under the authority of the Standards Board and comes into effect on 15 March 1995 BSI 08-1999 The following BSI references r
3、elate to the work on this standard: Committee reference CPM/10 Draft for comment 83/40601 DC ISBN 0 580 23909 8 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Consumer Products and Services Sector Board to Technical Committee CPM/10, up
4、on which the following bodies were represented: Association of Teachers of Printing and Allied Subjects British Association of Oral and Maxillo-Facial Surgeons British Dental Association British Kinematograph, Sound and Television Society British Photographic Association British Printing Industries
5、Federation College of Radiographers Institute of Physics Institute of Practitioners in Advertising Lighting Industry Federation Ltd. Ministry of Defence Oil and Colour Chemists Association PICON Periodical Publishers Association Ltd. Photogrammetric Society Pira International Royal Photographic Soci
6、ety University of Westminster Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:36:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 7004:1987 BSI 08-1999i Contents Page Committees responsibleInside front cover National forewordii F
7、orewordiii Text of ISO 70041 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:36:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 7004:1987 ii BSI 08-1999 National foreword This British Standard reproduces verbatim ISO 7004:1987 and implements it as the UK national standard. It supersed
8、es BS 5230:1975 which is withdrawn. This British Standard is published under the direction of the Consumer Products and Services Sector Board whose Technical Committee CPM/10 has the responsibility to: aid enquirers to understand the text; present to the responsible international committee any enqui
9、ries on interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. NOTEInternational and European Standards, as well as overseas standards, are available from Customer Services, BSI, 389 Chiswick Hig
10、h Road, London W4 4AL. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages T
11、his document comprises a front cover, an inside front cover, pages i and ii, the ISO title page, pages ii to iv, pages 1 to 8 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside fr
12、ont cover. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:36:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:36:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 7004:1987 (E) ii BSI 08-1999 Contents Page Forewordiii 0Introduction1 1
13、Scope and field of application1 2References1 3Definitions1 4Sampling and storage1 5Method of test1 6Product classification3 7Product marking and labelling4 Annex A Calibration of ionization chambers7 Annex B Beam quality code7 Annex C Improvement of the reproducibility of exposure to X-rays7 Annex D
14、 Scattered radiation measurement8 Annex E Units of measure energy8 Bibliography8 Figure Determination of ISO speed and ISO average gradient6 Table 1 ISO speed scale3 Table 2 ISO average gradient scale4 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:36:29 GMT+00:00 2006, Uncontrolled Copy,
15、 (c) BSI ISO 7004:1987 (E) BSI 08-1999iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member
16、body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical
17、 committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 7004 was prepared by Techni
18、cal Committee ISO/TC 42, Photography. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov
19、26 12:36:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:36:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 7004:1987 (E) BSI 08-19991 0 Introduction This is the first International Standard to specify methods for measuring the ISO s
20、peed and ISO average gradient of industrial radiographic film when exposed directly to X and radiation. Many countries have had national standards relating to this subject for many years and may provide values which are different from those obtained by following the procedure specified in this Inter
21、national Standard. Since the photographic characteristics of a film are dependent on the energy distribution in the wavelength spectrum, four representative sources are specified for determining sensitometric characteristics. Photographic results are also dependent on the chemical process used to de
22、velop the film. This International Standard does not attempt to specify the process method; therefore, when ISO speed or ISO average gradient values are given for a film, it is necessary to specify not only the radiation quality used, but also the process. This will facilitate the comparison of film
23、/film process systems. 1 Scope and field of application This International Standard specifies methods for determining ISO speeds and ISO average gradients of industrial radiographic film/film process combinations when exposed directly to X- and -rays. The evaluation of films used in industrial radio
24、graphy with fluorescent intensifying screens is not specified in this International Standard. 2 References ISO 5, Photography Density measurements Part 1: Terms, symbols and notations Part 2: Geometric conditions for transmission density Part 3: Spectral conditions. ISO 4037, X and reference radiati
25、ons for calibrating dosemeters and dose ratemeters and for determining their response as a function of photon energy. 3 Definitions For the purpose of this International Standard, the following definitions apply. 3.1 exposure (to X- or -rays), K the time integral of the X- or -radiation incident on
26、the film, expressed in terms of the kinetic energy of electrons released per kilogram of air measured in grays exposure is often expressed in log10 K units 3.2 speed a quantitative measure of the response of the photographic material to radiant energy for specified conditions of exposure, processing
27、, and image measurements 3.3 average gradient, the slope of the straight line joining two points on a sensitometric curve 3.4 gray1) a measure of X and gamma radiation required to create 1 joule of initial kinetic energy of charged particles created by the radiation impinging on 1 kg of air 1 Gy = 1
28、 J/kg of air is equivalent to 114,5 R or is equivalent to 0,029 5 C/kg 4 Sampling and storage In determining the ISO speed and ISO average gradient of a product, it is important that the samples evaluated yield the average results obtained by users. This will require evaluating several different bat
29、ches periodically under conditions specified in this International Standard. Prior to evaluation, the samples shall be stored according to the manufacturers recommendations for a length of time to simulate the average age at which the product is normally used. Several independent evaluations shall b
30、e made to ensure the proper calibration of equipment and processes. The basic objective in selecting and storing samples as described above is to ensure the film characteristics are representative of those obtained by a consumer at the time of use. 5 Method of test 5.1 Principle Samples are exposed
31、and processed as specified below. Measurements are obtained from the resultant images to produce a sensitometric curve from which values are taken and used to determine ISO speed and ISO average gradient. 5.2 Safelights To eliminate the possibility of safelight illumination affecting the sensitometr
32、ic results, all films shall be handled in complete darkness during exposing and processing. 1) See Annex E. G Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 12:36:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 7004:1987 (E) 2 BSI 08-1999 5.3 Exposure2) 5.3.1 Film holders Films or film/scr
33、een combinations shall be exposed in holders which provide less than 2 % absorption of the radiation specified (without lead screens). 5.3.2 Sample condition During exposure, the samples shall be at a temperature of 23 5 C and a relative humidity of (50 20) %. 5.3.3 Radiant energy quality3) Four spe
34、cific exposing sources are recognized in this International Standard for determining speed and average gradient to cover the range of exposing conditions used in practice. The selection of which of the four sources are used to determine ISO speed and ISO average gradient depends on how the film is u
35、sed. 5.3.3.1 X-rays from a low potential source Film under test shall be exposed to X-rays from tungsten target tubes. Inherent filtration of the tube, plus an additional copper filter4) located as close to the target as possible shall provide a filtration equivalent to 2,0 0,1 mm of copper. The pot
36、ential across the X-ray tube shall be adjusted until the half-value absorption is obtained with 1,0 0,1 mm of copper (i.e. the intensity of the X-ray beam with a filtration equivalent to 3,0 mm shall be one-half the value obtained with the total filtration equivalent to 2,0 mm of copper). A potentia
37、l of approximately 120 kV generally meets this requirement. No lead screen shall be used.5) This is designated source (1). 5.3.3.2 X-rays from a high potential source Film under test shall be exposed to X-rays from tungsten target tubes. Inherent filtration of the tube, plus an additional copper fil
38、ter located as close to the target as possible shall provide a filtration equivalent to 8,00 0,05 mm of copper. The potential across the X-ray tube shall be adjusted until the half-value absorption is obtained with 3,5 0,2 mm of copper. A potential of approximately 220 kV generally meets this requir
39、ement. Films shall be exposed without interleaving paper and shall be between lead-foil screens.3) The front screen shall be 0,115 0,020 mm thick. The total thickness of the back screen(s) shall be 0,20 0,06 mm. Single-coated films shall be exposed with the emulsion-coated surface facing the X-ray t
40、ube. To obtain sufficient contact, vacuum cassettes shall be used. This is designated source (2). 5.3.3.3 -Rays from an iridium-192 (192Ir) source A filtration of 8,0 mm of copper near the source is required. Lead-foil screens shall be used as indicated in 5.3.3.2. This is designated source (3). 5.3
41、.3.4 -Rays from a cobalt-60 (60Co) source Lead-foil screens shall be used as indicated in 5.3.3.2. This is designated source (4). 5.3.4 Scattered radiation To minimize scattered radiation when exposing test films, X-ray and -ray beams shall be diaphragmed to as small a size as will permit a uniform
42、exposure field for the films (and the measuring device, if included). The amount of scattered radiation reaching the film and measuring device shall be no greater than 6 % of the primary radiation. Constructing the supports for the film, filters, and ion chamber from low atomic number materials and
43、making such structures as light in mass as possible will minimize scattered radiation (see Annex D). 5.3.5 Modulation The film shall be given a graduated series of exposures such as will result in a series of densities above base plus fog from 1,0 to 4,0. The exposure over the useful area of each ex
44、posure step shall be uniform to within 3 %. Exposure increments shall not exceed 0,15 log10 K units. Each exposure shall be measured in grays by using an ionization chamber calibrated for the radiant energy quality and intensity used for exposing the film. A separate sample of the film shall be left
45、 unexposed for measuring inherent base plus fog density. 2) For convenience in this International Standard, exposure is expressed in terms of the air kerma (measured in grays) that would be produced in 1 kg of air. Kerma, specific energy and absorbed dose are all measurements of energy per unit mass
46、 imparted by ionizing radiation (see Annex E). 3) A trial exposure should be made to make sure that the lead-foil screens do not produce streaks or other obvious defects. 4) All copper filters specified in this International Standard should be made of 99,9 % pure copper. 5) For films packaged by a m
47、anufacturer in light-tight exposures which contain intensifying screens, the film should be tested as packaged without the use of a film holder. The ISO speed or average gradient values for such films should include the trade designation of the product. Licensed Copy: sheffieldun sheffieldun, na, Su
48、n Nov 26 12:36:29 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ISO 7004:1987 (E) BSI 08-19993 5.4 Processing 5.4.1 Conditioning of samples In the time interval between exposure and processing, the samples shall be kept at 23 5 C and a relative humidity of (50 20) %. The processing shall be started bet
49、ween 30 min and 8 h after exposure. 5.4.2 Processing specifications No processing specifications are described in this International Standard in recognition of the wide range of chemicals and equipment used. ISO speed and ISO average gradient data provided by the film manufacturer generally apply to the film when it is processed in accordance with his recommendations to produce the photographic characteristics specified for the process. Process information shall be available from the film manufacturer or others who quo
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