1、 STD-BSI BS EN L30b8-2-ENGL 2000 1111 Lb24bb9 0832683 27T 11111 BRITISH STANDARD Non-destructive testing - Radioscopic testing - Part 2: Check of long term stability of imaging devices The European Standard EN 13068-21999 has the status of a British Standard ICs 19.1M) NO COPYING WITHOUT BSI PERMISS
2、ION EXCEPT AS PERMInED BY COPYRIGHT LAW BS EN 13068-2:2000 STD*BSI BS EN 13068-2-ENGL 2000 W Lb24bb9 0832684 Lob H BS EN 13068-2:ZOOO direction of the Engineering Amd. No. Date Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 March 2000 Natio
3、nal foreword Comments This British Standard is the official English language version of EN 130682: 1999. The UK participation in its preparation was entrusted to Technical Committee WEW46, Nondestructive testing, which has the responsibility to: - aid enquirers to understand the text; - present to t
4、he responsible European committee any enquiries on the - monitor related international and European developments and promulgate interpretation, or proposals for change, and keep the UK interests informed them in the UK A list of organizations represented on this committee can be obtained on request
5、to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the B
6、SI Standards Electx-onic Catalogue. 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. Summa
7、ry of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 8, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. O BSI 03-2000 ISBN O 580 35678 7 I I STD.BS1 BS EN 130b8-
8、2-ENGL 2000 I1624669 0832t85 042 11$1 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13068-2 December 1999 ICs 19.100 English version Non-destructive testing - Radioscopic testing - Part 2: Check of long term stability of imaging devices Essais non destructifs - Contrle par radioscopie - Patti
9、e 2: Contrle de la stabilit iong terme des systmes dimagerie Zerstrungsfreie Prfung - Radioskopische Prfung - Teil 2: Prfung der Langzeitstabilitt von bildgebenden Systemen This European Standard was approved by CEN on 29 October 1999. CEN members are bound to comply with the CENKENELEC Internal Reg
10、ulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This
11、European Standard exists in three oficial versions (English, French, German). A version in any other language made by traislation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as tie official versions. CEN members are the n
12、ational standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION EUROPISCHES KOMITEE FUR NORMUNG COMITE EU
13、ROPEEN DE NORMALISATION Central Secretariat: rue de Stassart, 36 B-1050 Brussels O 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13068-21999 E STDmBSI BS EN 130b8-2-ENGL 2000 Lb24669 0632b8b T89 m Page 2 EN 13068-2: 1999 Con
14、tents Foreword . 3 Introduction . 4 1 Scope 4 2 Normative references . 4 3 Comparison with natural defects 4 4 image quality by Image Quality Indicators (IQls) . 5 5 Identification of equipment faults 6 6 Documentation 6 STDWBSI BS EN L30bd-Z-ENGL 2000 Lb24669 0832687 915 Page 3 EN 1 3068-2: I999 Fo
15、reword This European Standard has been prepared by Technical Committee CENITC 138, Nondestructive testing, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest b
16、y June 2000, and conflicting national standards shall be withdrawn at the latest by June 2000. According to the CENKENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, F
17、inland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. EN 13068 comprises a series of European Standards of radioscopic systems which is made up the following: EN 13068-1 : 1999, Non-destructive testing
18、- Radioscopic testing - Pari i: Quantitative measurement of imaging properties. EN 13068-2: 1999, Non-destructive testing - Radioscopic testing - Part 2: Check of long term stability of imaging de vices. prEN 13068-3, Non-destructive testing - Radioscopic testing - Pari 3: General principles of radi
19、oscopic testing of metallic materials by X- and gamma rays. OBSI 03-2000 STD-ES1 ES EN L30b-2-ENGL 2000 Lb24bb9 0832688 851 6 Page 4 EN 13068-2:1999 Introduction This part of the European Standard gives an outline for the quality control of the imaging devices during operation. Reference is made to
20、part 1 which deals with the quantitative measurements. A further part 3 and others will be related to special applications, e. g. weld inspection, casting inspection, etc. Before operation of a new radioscopic system, a quality control procedure should be specified by the producer and the user of th
21、e system which ensures the stable and reliable performance of the radioscopic system. This procedure should include the parts of this standard, specify the region of interest (ROI) on the display unit, placement of test IQIs and other relevant parameters for good reproducibility of the tests. Additi
22、onally, the frequency of tests and acceptance levels for system degradation should be specified according to the requirements of NDT specifications and usage of the system. 1 Scope This part of the standard gives guidance on the on-site check of equipment for radioscopy where the image is presented
23、on a display unit including image processing. The radiation sources used can be X-rays or gamma rays. This standard establishes rules for testing a radioscopic system to assure a constant level of inspection quality. The tests should be easily performable by the operators of the system. They are bas
24、ed on an input signal from defined image quality indicators. The measurement of the systems response should be performed with the same equipment which is in use in this particular installation. This standard is applicable to installations with an image processing computer as well as to simple displa
25、y units. 2 Normative references This European Standard incorporates, by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to
26、 or revisions of any of these publications apply to this European standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 13068-1 : 1999, Non-destructive testing - Radioscopic examination - Part 1: Quantitat
27、ive measurement of imaging properties. EN 462-1, Non-destructive testing - Image quality of radiographs - Part I: Image quality indicators (wire type) - Determination of image quality value. EN 462-2, Non-destructive testing - Image quality of radiographs - Part 2: Image quality indicators (step/hol
28、e type) - Determination of image quality value. EN 462-5, Non-destructive testing - Image quality of radiographs - Part 5: Image quality indicators (duplex wire type), determination of image unsharpness value. 3 Comparison with natural defects Tests with natural defects are not sufficient as the onl
29、y quality control for the comparison of the actual system performance with the first day appearance. The performance of the radioscopic system should be tested to its ability to image and recognize the typical and the critical defects of a certain component. In addition to standardized IQls, samples
30、 with smallest or most difficult to detect natural defects can be used for a routine quality control of the overall system performance. OBSI 03-2000 STDmBSI BS EN 13068-2-ENGL 2000 m L6246b9 0832689 798 Page 5 EN 13068-2:1999 4 Image quality control by image quality indicators (IQls) 4.1 General The
31、 quality of a radioscopic image is essentially determined by sharpness, contrast and linearity. These parameters which have been described in EN 13068-1:1999 depend on the Set-up of source, imaging system and specimen. For the purpose of quality control they shall be supervised by checking the overa
32、ll performance of the radioscopic set-up on a routine basis during operation and with the same operational set-up used in usual operation. This can be achieved by means of image quality indicators. For all specimens the IQI has to be placed at the source side of the specimen if this is possible. If
33、there are additional parts of this standard on specific inspection subjects (e.9. prEN 13068-3), they shall be supplied during quality control. 4.2 Experimental procedure 4.2.1 General set-up To achieve reproducible results which allow the control of the long term stability of a system, it is necess
34、ary to define a standardized set-up for the measurements. An example is shown in Figure 1. Its details shall be documented for later reproduction. lhe document shall contain the data of the X-ray source, such as type of tube, voltage and current settings, filtering of X-rays and additional details,
35、which may influence the image quality. Collimators when used shall be described. Test indicators shall be placed at the source side of the component under inspection. They produce a defined radiation relief as an input signal. The performance tests shall be carried out with the same equipment and pa
36、rameter settings as used under operational conditions. During measurements the radioscopic system shall be operated in accordance with the instruction manual and manufacturers instructions. 4.2.2 Display unit Display units used in radioscopy shall be operated with selectors for brightness and contra
37、st, properly adjusted following the instructions of the manufacturer. For systems with a frame buffer a digitized test chart should be loaded for the adjustment of the display unit. Test charts for this purpose can be taken from standard video technique. The settings shall not be changed until the n
38、ext test. 4.3 Measurement procedures 4.3.1 Check of unsharpness The sharpness of the system can be degradated mainly by the lenses, the signal detector and ageing processes of the converter screens. For tests during practical work the total system unsharpness can be registered only. The total system
39、 unsharpness shall be checked with an image quality indicator (IQI) of the duplex wire type according to EN 462-5 as the test obje-. It shall be placed on the source side of the object. The object shall be plane and represent the typical test specimen in terms of thickness and material. The unsharpn
40、ess is position dependent. A region of interest (ROI) on the field of view shall be defined, where the image quality shall fulfill the sharpness criteria given by the particular inspection problem. The unsharpness shall meet these conditions in the whole ROI. The unsharpness shall be checked by plac
41、ing the IQI horizontally and vertically in the direction of the detector read out lines. For systems with an image processing computer, the profile across the IQI shall be evaluated. The profiles are similar to Figure 2. The number of the duplex wire for which the modulation depth is closest to 20 %
42、 and the numerical value of the modulation depth itself shall be evaluated and documented for comparison with later measurements. Also, the number of the first unresolved wire pair according to the EN 462-5 shall be written to the document file. OBSI 03-2000 STD-BSI BS EN L30b-2-ENGL 2000 lb24669 08
43、32b70 40T 111 Page 6 EN 13068-2: 1999 The total unsharpness required depends on the radiation energy to be used with the equipment. The arrangement parameters shall be documented for later reproduction. 4.3.2 Check of contrast sensitivity For the measurement of contrast sensitivity and wall thicknes
44、s range, a step wedge in accordance with EN 13068-1:1999, made of the same material as the sample under investigation, can be used. In addition, to comply with the requirements for standard radiography, the corresponding IQI according to EN 462-1 or EN 462-2 has to be placed accordingly. If integrat
45、ed to the system, noise reduction by recursive filtering or image integration can be used. The type of algorithm and relevant parameters shall be documented for proper reproduct ion. The detectability of the corresponding radiographic IQI can be used as a sufficient image quality indication with res
46、pect to the signal noise ratio. This should be measured with an image processing computer if there is one integrated to the inspection system. 4.3.3 Check of homogeneity During the lifetime of an imaging system there can be some degradation of homogeneity due to masking or burn-out of the luminescen
47、ce screens or of the optical or camera system. The local inhomogeneities can be outside the areas to be evaluated and of no relevance. However, disturbances in homogeneity within the regions of interest may heavily deteriorate the image and therefore the image evaluation. The control of inhomogeneit
48、y in an image is carried out by placing the IQls used for the test of contrast sensitivity and spatial resolution at various areas of the regions of interest. The locations and type of IQI shall be documented. The time dependence of the homogeneity within the image can be measured with an image proc
49、essing system by comparison of the actual image to an image stored at the time of installation. This can be done by image subtraction or intensity profile comparison. During the lifetime of an imaging system additional dark or light spots may occur which shall be registered on the display unit or measured and stored as x, y pixel address by the image processing system. In those cases, where dimensional measurements are carried out, the linearity of the imaging system has to be verified by appropriate calibration. 4.3.4 Systems for inspection of moving parts Radi
