1、STD-ES1 BS EN L3068-L-ENGL 2000 W Lb24bh9 U83Zb58 O34 BRITISH STANDARD Non-destructive testing - Radioscopic testing - Part 1: Quantitative measurement of imaging properties The European Standard EN 13068-1 1999 has the status of a British Standard ICs 19.100 NO COPYING WITHOUT BSI PERMISSION EXCEPT
2、 AS PERMITTED BY COPYRIGHT LAW 3s EN 13068- 1 :2000 STD.BSI BS EN L30b-1-ENGL 2000 = Lb24bb9 0832b59 TS0 R BS EN 13068-1:2000 direction of the Electrotechnical Amd. No. Da Sector Committee, was published under the authority of the standards Committee and comes into effect on 15 March 2OOO National f
3、oreword Comments This British Standard is the official English language version of EN 13068-1: 1999. The UK participation in its preparation was entrusted to Technical Committee WEW46, Non-demctive testing, which has the responsibility to: - aid enquirers to undentand the text; - present to the resp
4、onsible 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 to its
5、 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 “Fnd” facility of the BSI Stan
6、dards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a conh-act. Users of British Standards are responsible for theh- correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pa
7、ges This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 22, 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 032OOO I I ISBN O 580 35680 9 EUROPEAN STANDARD EN 13068-1
8、 NORME EUROPENNE EUROPISCHE NORM December 1999 ICs 19.100 English version Non-destructive testing - Radioscopic testing - Part 1 : Quantitative measurement of imaging properties Essais non destructifs - Contrle par radioscopique - Partie 1 : Mesure quantitative des caractristiques dimage Zerstrungsf
9、reie Prfung - Radioskopische Prfung - Teil 1: Quantitative Messung der bildgebenden Eigenschaften This European Standard was approved by CEN on 29 October 1999 CEN members are bound to comply with the CENICENELEC Internal Regulations which stipulate the conditions for giving this Europan Standard th
10、e status of a national standard without any alteration. Up-todate lists and bibliographical references concerning slch national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German)
11、. A version in any other language made by trmslation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as he official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland
12、, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMIlTEE FOR STANDARDIZATION COMIT EUROPEEN DE NORMALISATION EUROPISCHES KOMITEE FOR NORMUNG Central Secretariat: rue de Stassart, 36 8-1050 Brussel
13、s O 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13068-1:1999 E STD=BSI BS EN L3068-L-ENGL 2OO m Lb24bb Page 2 EN 13068-1 :1999 Contents Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Scope . 2 Normative references . . . . . . . . . . . . . . . . . . . . .
15、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Radioscopic system , , . . , , . , . . . . . . . . . , . . . . . . . . . . . ._. . . . . . . . . . . . . . . . . . . ._. . . . . . . . . . . . . . . . . . . . . . . .
16、 . . . . . . . . . . . . . . . . . . 4 Measurement of image quality parameters . . . . . . . . . Annex A (informative) Example for a test report according to EN 13068-1 . . . . . . . . . 3 4 4 4 5 22 OBSI 03-2000 STD.BS1 BS EN L3068-1-ENGL 2000 Lb24669 08326h2 545 m Page 3 EN 13068-1 11 999 Foreword
17、 This European Standard has been prepared by Technical Committee CENTTC 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 by June
18、 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, Finland
19、, 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 of the following: EN 13068-1 : 1999, Non-destructive testing - Radi
20、oscopic testing - Part 7: Quantitative measurement of imaging properties. EN 13068-2: 1999, Non-destructive testing - Radioscopic testing - Part 2: Check of long term stability of imaging devices. prEN 13068-3, Non-destructive testing - Radioscopic testing - Part 3: General principles of radioscopic
21、 testing of metallic materials by X- and gamma-rays. Annex A is informative. OBSI 03-2000 STD-BSI BS EN 23068-L-ENGL 2000 W Lb24bb9 0832bb3 Y54 111 Page 4 EN 13068-1 11 999 1 Scope The procedures given in this standard can be applied to all radioscopic systems which provide an electronic signal to a
22、 display unit or an automated image interpretation system. The radioscopic system is analysed for the response to a well defined test specimen. The measurement should be performed by a sufficiently equipped laboratory. From the results, the specifications of the imaging system regarding image proper
23、ties can be derived. This standard so far does not include imaging properties under moving conditions. 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
24、text and the publications are listed hereafter. For dated references, subsequent amendments to 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 app
25、lies. EN 29241-2, Ergonomic requirements for office work with visual display terminals (VDTs) - Part 2: Guidance on task requirements. (IS0 9241 -2: 1992) EN 29241-3, Ergonomic requirements for ofice work with visual display terminals (VDTs) - Patt 3: Visual display requirements. (IS0 9241-3:1992) 3
26、 Radioscopic system In the context of this standard a radioscopic system consists of a radiation source, a handling system, collimators, filters and an imaging device. An imaging device consists of an X- or gamma ray conversion device which transforms the radiation relief into an output signal S for
27、 numerical or optical presentation (see Figure 1). Image processing systems can be part of the imaging device. In the case of visual evaluation it includes the display unit. In cases of fully automated image evaluation systems the display unit is not part of the system. E-, 1 -. 1 Radiation source 2
28、 Object 3 Radiation conversion device 4 Output signal 5 Image processing 6 Display unit 2 r, L. -7 5 . b Figure 1 -Typical arrangement of an imaging device OBSI 03-2000 STD-BSI BS EN L30b-1-ENGL 2000 W Lb24bb9 0832bhli.i 3L II Page 5 EN 13068-1 : 1 999 For the specification of the imaging properties
29、 of imaging devices, terms and parameters of information thec and radiographic testing are used. The parameters in Table 1 define the image quality of imaging devices. In some descriptions of image qualiiy parameters the term “signal-to-noise-ratio (SNR)“ is used. Within the meaning of information t
30、heory, SNR is the ratio of the actual partial scale signal AS to rms-value SRMS of the overlay noise signal (see Figure 2). a Signal Figure 2 - Determination of AS and SRMS from output signal S 4 Measurement of image quality parameters 4.1 Principle 4.1 .I Conversion device The basis of all measurem
31、ents with the conversion device is the use of a defined radiation relief by artificial test indicators as an input signal and the measurement of the system response in the linear raw output signal with suitable measuring equipment (see Figure 1). All measurements shall be done with the imaging devic
32、e itself. In Figure 3 the principle set up for all measurements is shown. The radiation filter shall be placed in front of the X-ray tube. Collimators shall be used to reduce scattering radiation. All test indicators shall be placed in front of the input screen of the conversion device. They produce
33、 a defined radiation relief as an input signal. Measuring equipment shall be connected to the final output signal for measurement of the total system response. For video signals the measuring equipment shall fulfill the following minimum requirements: - - - Bandwidth 2 50 MHz: Amplitude resolution 2
34、 1 O Bit; Time resolution 2 1 O Bit = 1024 sample points; - - Signal averaging function. Minimum sampling rate 2 I O0 MHz; OBSI 03-2000 STD.BSI BS EN L30bB-L-ENGL 2000 Lb24669 08326b5 254 m O O O 9 ti O (o m Q - STD-ES1 BS EN L30bB-L-ENGL 2000 = Lb24bb7 0832666 170 Y - I c I Y II Y 6 3 L II 3 ? C O
35、O X .- 7 n Y I U II U- .- .- U C 0 9 rc O O O O x O - o m Q STD.BS1 BS EN L3068-L-ENCL 2000 W 3624667 0832667 O27 I Tube voltage Radiation filter thickness and material a) kV mm Page 8 EN 13068-1 : 1999 50 1 O0 150 Because image quality parameters are dependent on radiation energy and quality, measu
36、rements shall be done in the lower, middle and upper pari of a permissible energy range of the radioscopic system with constant potential X-ray equipment. In order to guarantee a defined radiation quality, the radiation filtering shall be used as given in Table 2. The tube current shall be adjusted
37、to give a dose rate of 0,Ol mGy/min; 0,l mGy/min; 1 ,O mGy/min or 10 mGy/min at the input plane of the conversion device. 7 f 0,5 AI 22 f 0,5 AI 7 f 0,5 Cu 400 400 25 f 0,5 Cu 35 f 0,5 Cu 200 I 12 f 0,5 Cu 300 15 i 0.5 Cu laThe Duritv of the filter material should be better than 99 % I During measur
38、ements the radioscopic system shall be operated in accordance with the instruction manual and manufacturers instructions. The radiation intensity shall be adjusted to such a value that in the middle of the input screen behind the radiation filter (without any test specimen) the output signal S shows
39、 the maximum signal amplitude &,.The radiation intensity shall be measured with an ionization chamber in the middle in front of the input screen and documented together with all other measuring results. X-ray detectors should have a sufficient period of use (e. g. for X-ray image intensifiers I Gy)
40、before the measurements are made. 4.1.2 Display unit and image processor For assessment of display units and image processors the following procedure is recommended. A bar pattern is generated by an electronic test pattern generator according to the requirements of 4.1.1 for measuring equipment (acc
41、ording to EN 29241-2 and EN 29241-3). The generator shall be able to produce vertical bars up to the limiting bandwidth of the display unit or image processor. The bar pattern is displayed on the image display unit. For evaluation a small section (max. 10 % of the total display area) is picked up by
42、 an optical sensor. The result is digitized. Suitable optical sensors are TV cameras or linear line-scan cameras. The magnification scale shall be at least 10. Therefore, at least 10 pixels in the frame buffer are available for the presentation of 1 pixel on the TV monitor. Beating effects between t
43、he pixel frequencies of the display unit and camera can be compensated by signal integration. 4.2 Measurement procedures 4.2.1 Conversion device 4.2.1.1 Sharpness (spatial resolution) In order to characterize the system sharpness the following three image quality parameters shall be measured: a) Inh
44、erent uncharmess For measurement of the inherent unsharpness Ui see equation (2) an intensity step function shall be produced by a sharp edge of absorbent material (Figure 4). The image of the edge shall be located in the centre of the input screen perpendicular and horizontal to the read out line o
45、f the detector. The radiation intensity shall be adjusted by the tube current according to the selected values as given in 4.1. In order to reduce the effect of scattered radiation the input screen shall be covered by absorbing material whereby approximately 1 O % of the input screen should be irrad
46、iated only. OBSI 03-2000 Page 9 The system shall be adjusted such that the output signal shows a black-to-white signal (Edge Spread Function ESF) with a minimum signal amplitude of 90 % of the maximum electronic signal amplitude and an overshoot less than i0 %. The inherent unsharpness is proportion
47、al to the rise timet, of the edge spread function. If there is an adjustable diaphragm the setting shall be stated in the protocol. EN 13068-1 : 1 999 A second measurement will give the value for the scale factor sc in order to calculate the inherent unsharpness in millimetres (Figure 5). The edge s
48、hall be substituted by a test indicator with well-known length I and the corresponding dimension (time interval for an output signal)x, shall be measured see equation (l). I Sc =- X, Ui = sc . t, with overshoot I 1 O YO with tr =f90% x ESF-f10% Y ESF b) Spatial modulation transfer function (MTF) The
49、 starting point for the calculation of the MTF is the edge spread ,Jnction ,om the former unsharpness measurement (Figure 6). The edge spread function shall be digitized with high resolution and stored in a computer. The sampling theorem shall be considered. In the next step the ESF shall numerically be differentiated in order to get the Line Spread Function LSF. The magnitude spectrum of the Fourier- transformed LSF will give the MTF. For a common representation of MTF curve the modulation rn for the spatial frequency f = O Lp/mm shall be normali
