DIN EN 12543-2-2008 Non-destructive testing - Characteristics of focal spots in industrial X-ray systems for use in non-destructive testing - Part 2 Pinhole camera radiographic met.pdf

1、October 2008DEUTSCHE NORM English price group 8No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 19.100!$RGp“1473677www.

2、din.deDDIN EN 12543-2Non-destructive testing Characteristics of focal spots in industrial X-ray systems for use innon-destructive testing Part 2: Pinhole camera radiographic methodEnglish version of DIN EN 12543-2:2008-10Zerstrungsfreie Prfung Charakterisierung von Brennflecken in Industrie-Rntgenan

3、lagen fr die zerstrungsfreiePrfung Teil 2: Radiographisches Lochkamera-VerfahrenEnglische Fassung DIN EN 12543-2:2008-10SupersedesDIN EN 12543-2:1999-12www.beuth.deDocument comprises 13 pagesDIN EN 12543-2:2008-10 2 National foreword This standard has been prepared by Technical Committee CEN/TC 138

4、“Non-destructive testing” (Secretariat: AFNOR, France). The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Technical Committee NA 062-08-22 AA Durchstrahlungsprfung und Strahlenschutz. Amendments This standard diffe

5、rs from DIN EN 12543-2:1999-12 as follows: a) Subclauses 4.3, 4.4, 5.1 and 5.2 have been revised to describe besides radiographic films also digital radiographic detectors to measure the focal spot size. b) The standard has been editorially revised. Previous editions DIN EN 12543-2: 1999-12 EUROPEAN

6、 STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12543-2 July 2008 ICS 19.100 Supersedes EN 12543-2:1999 English Version Non-destructive testing - Characteristics of focal spots in industrial X-ray systems for use in non-destructive testing - Part 2: Pinhole camera radiographic method Essais non destruc

7、tifs - Caractristiques des foyers missifs des tubes radiognes industriels utiliss dans les essais non destructifs - Partie 2: Mthode radiographique par stnop Zerstrungsfreie Prfung - Charakterisierung von Brennflecken in Industrie-Rntgenanlagen fr die zerstrungsfreie Prfung - Teil 2: Radiographische

8、s Lochkamera-Verfahren This European Standard was approved by CEN on 7 June 2008. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and

9、bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibi

10、lity of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland,

11、 Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Sta

12、ssart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12543-2:2008: EEN 12543-2:2008 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Test equipm

13、ent 5 5 Measurement and determination of the focal spot size.8 Bibliography 11 Annex A (informative) Preferred values of d for the characterization of X-ray tube types10 DIN EN 12543-2:2008-10 EN 12543-2:2008 (E) 3 Foreword This document (EN 12543-2:2008) has been prepared by Technical Committee CEN

14、/TC 138 “Non-destructive 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 January 2009, and conflicting national standards shall be withdrawn at

15、 the latest by January 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 12543-2:1999. EN 12543-2 is p

16、art of a series of European Standards under the general title Non-destructive testing Characteristics of focal spots in industrial X-ray systems for use in non-destructive testing; the other Parts are the following: EN 12543-1: Part 1: Scanning method; EN 12543-3: Part 3: Slit camera radiographic me

17、thod; EN 12543-4: Part 4: Edge method; EN 12543-5: Part 5: Measurement of the effective focal spot size of mini and micro focus X-ray tubes. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standar

18、d: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DI

19、N EN 12543-2:2008-10 EN 12543-2:2008 (E) 4 Introduction In order to cover the different requirements for focal spot size measurement, five different methods are described in EN 12543-1 to EN 12543-5. The scanning method (EN 12543-1) is dedicated to those applications where quantitative values for th

20、e intensity distribution and spot size are needed, i.e. calibration and image processing purposes. The radiographic methods (EN 12543-2 and EN 12543-3) describe the traditional techniques and are dedicated for certification purposes and for field applications. A digital detector not only provides fo

21、cal spot length and width, but also the user with quantitative values for intensity distribution. The digital method may be used as a reference method as in EN 12543-1 Where no pinhole or slit cameras are available in the field, the edge method (EN 12543-4) may be applied. It represents a very simpl

22、e method for field application. For micro focus systems, see EN 12453-5. DIN EN 12543-2:2008-10 EN 12543-2:2008 (E) 5 1 Scope This European Standard specifies a method for the measurement of focal spot dimensions above 0,2 mm of X-ray systems up to and including 500 kV tube voltage by means of the p

23、inhole camera radiographic method. The voltage applied for this measurement is restricted to 200 kV for visual film evaluation. The image quality and the resolution of X-ray images depend highly on the characteristics of the focal spot, in particular the size and the two dimensional intensity distri

24、bution. For the characterisation of commercial X-ray tube types (i.e. for advertising or trade) the specific values of Table A.1 are used. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited ap

25、plies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 462-5, Non-destructive testing Image quality of radiographs Part 5: Image quality indicators (duplex wire type), determination of image unsharpness value EN 584-1, Non-destructive test

26、ing Industrial radiographic film Part 1: Classification of film systems for industrial radiography EN 12543-1:1999, Non-destructive testing Characteristics of focal spots in industrial X-ray systems for use in non-destructive testing Part 1: Scanning method 3 Terms and definitions For the purposes o

27、f this document, the following terms and definitions apply. 3.1 focal spot X-ray emitting area on the anode of the X-ray tube as seen from the measuring device EN 12543-1:1999 4 Test equipment 4.1 Essential characteristics of the pinhole The pinhole camera shall consist of a diaphragm with a pinhole

28、 having the following dimensions according to Table 1 dependent from the actual focal spot size: Table 1 Dimensions of the pinhole Focal spot size mm Diameter P m Height H m 0,2 to 1,0 30 5 75 10 1,0 100 5 500 10 DIN EN 12543-2:2008-10 EN 12543-2:2008 (E) 6 The dimensions P and H are given in Figure

29、 1. Dimensions in millimetres Key 1 focal spot Figure 1 Essential dimensions of a pinhole diaphragm The pinhole diaphragm shall be made of tungsten or of a similar absorbant material. 4.2 Alignment and position of the pinhole camera The angle between the beam direction and the pinhole axis (see Figu

30、re 2) shall be smaller than 3. When deviating from Figure 2, the direction of the beam shall be indicated. Key 1 focal spot 2 beam direction 3 maximum deviation of the axis of the pinhole Figure 2 Alignment of the pinhole camera DIN EN 12543-2:2008-10 EN 12543-2:2008 (E) 7 The incident face of the p

31、inhole diaphragm shall be placed at a distance m from the focal spot so that the variation of the magnification over the extension of the actual focal spot does not exceed 5 % in the beam direction. In no case shall this distance be less than 100 mm. 4.3 Position of the radiographic image detector T

32、he radiographic image detector shall be placed normal to the beam direction at a distance n from the incident face of the pinhole diaphragm determined from the applicable magnification according to Figure 3 and Table 2. Key 1 plane of anode 2 reference plane 3 radiographic image detector 4 magnified

33、 length of the effective focal spot 5 beam direction 6 incident face of the diaphragm 7 physical length of the actual focal spot Figure 3 Beam direction dimensions and planes DIN EN 12543-2:2008-10 EN 12543-2:2008 (E) 8 Table 2 Magnification for focal spot pinhole radiographs Focal spot size d mm Mi

34、nimum magnification n/m 0,2 to 2,0 3: 1 2,0 1: 1 4.4 Requirements on the radiographic image detector Radiographic films or digital radiographic detectors can be used, provided sensitivity, dynamic range and detector unsharpness allow capturing of the full spatial size of the focal spot image without

35、 detector saturation. The maximum allowed detector unsharpness is given by the geometrical unsharpness uGof the pin hole and is calculated according to: ()mnPu /1G+= (1) The detector unsharpness shall be determined with the duplex wire IQI according to EN 462-5. For correct quantitative measurements

36、 the minimum projected length and width of the focal spot image should be covered always by at least 20 detector pixels. The signal-to-noise ratio of the focal spot image (ratio of the maximum intensity value inside the focal spot and the standard deviation of the background signal outside) should b

37、e at least 50. The maximum intensity inside the focal spot should be above 50 %, but lower than 100 % of the maximum linear detector output value to achieve an image with good contrast. Imaging plates systems (Computed Radiography, CR) or digital detector arrays (e.g. based on CCD-, a-Si- or CMOS-de

38、tectors coupled to an X-ray fluorescent screen, direct converting detectors or image intensifiers with CCD cameras) may be used as digital image detectors. If radiographic film is used as image detector, it shall meet the requirements of the film system class C 6 or better according to EN 584-1 and

39、shall be used without screens. The film shall be exposed to give a maximum optical density between 1,5 and 2,5. For reference measurements, the film can be digitised with a maximum pixel size, which fulfils the requirements of the above unsharpness conditions, and evaluated according to 5.1. 4.5 Loa

40、ding factors The X-ray tube voltage shall be 75 % of the nominal tube voltage, but not more than 200 kV for visual film evaluation. For digital evaluation the maximum voltage is limited by the need that the background intensity is lower than half of the maximum intensity inside the focal spot. The X

41、-ray tube current shall be the maximum applicable tube current at the selected voltage. 5 Measurement and determination of the focal spot size 5.1 Measurement The grey scale image of the radiation detector shall be proportional to the X-ray dose. It shall be evaluated to measure the dimensions of th

42、e focal spot. The area of all pixels of the focal spot image with grey values higher than 10% of the maximum value (of a 3x3 pixel median filtered image to suppress outliers) above background intensity are used to represent the area of the focal spot (see Figure 4). An isodose contour plot at 10% of

43、 the maximum intensity (see Figure 6 in EN 12543-1:1999) may also be used to indicate the area of the focal spot. The focal spot size is determined by the extent of the focal spot area in x- and y-direction divided by the magnification factor (n/m) of the pinhole camera. If radiographic film is used

44、 as an image detector, it is evaluated visually using an illuminator with a uniform luminance of 2000 cd/m to 3000 cd/m. The visual evaluation shall be carried out using an X5 or X10 DIN EN 12543-2:2008-10 EN 12543-2:2008 (E) 9 magnifying glass, with a built-in reticle, with divisions of 0,1 mm. The

45、 resulting focal spot is defined by the visible extent of the blackened area, divided by the selected magnification factor. Key a) grey scale image, which is proportional to the X-ray dose, from a radiographic image detector (e.g. CR) b) evaluation result (binary image) based on a 10 % threshold bet

46、ween background intensity and maximum intensity of the focal spot image Figure 4 Evaluation of focal spot images 5.2 Determination of focal spot size Each focal spot size is described by its size l (length) in the direction of the tube axis and its size w (width) across the X-ray tube. The operating

47、 parameters of the X-ray tube shall be recorded. If the tube axis is not defined, then the direction of the electron trajectory is used instead. The larger of these sizes (l or w) shall be used as the “focal spot size d“. A specification of the focal spot sizes d on the X-ray tube shall refer to thi

48、s European Standard. If the focal spot size will be certified, the measurement result has to meet the values of EN 12543-1 within an uncertainty of 10 %. This is fulfilled if the focal spot image is acquired digitally considering the requirements of 4.4, 4.5 and 5.1. NOTE ASTM E 1165 describes a dif

49、ferent test method for determination of focal spot sizes of X-ray tubes by the pin hole method. The user of this CEN standard should note that the ASTM standard provides smaller values due to a different measurement procedure. DIN EN 12543-2:2008-10 EN 12543-2:2008 (E) 10 Annex A (informative) Preferred values of d for the characterization of X-ray tube types Table A.1 Preferred values of d in millimetres 0,1 0,15 0,2 0,3 0,4 0,5 0,6 0,8 1,0 1,4 1,8 2,2 2,6 3,0 3,5 4,0 4,5 5,0 5,5 6,0 7,0 8,0 9,0 10,0 Additio