1、STD-BSI BS EN 12544-3-ENGL 1777 lb24bb9 0818482 1 BRITISH STANDARD Non-destructive testing - Measurement and evaluation of the X-ray tube voltage - Part 3: Spectrometric method The European Standard EN 12544-31999 has the status of a British Standard ICs 19.100 7m BS EN 12544-3: 1999 NO COPYING WITH
2、OUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW STD=BSI BS EN 12544-3-ENGL 1999 9 1b2qbb7 0818983 055 9 direction of the Engineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 December 1999 Amd. No. O BSI 12-1999 BS EN 125443319
3、99 - - Date Comments National foreword This British Standard is the English language version of EN 1254431999. The UK participation in its preparation was entrusted to Technical Committee WEE46, Nondestructive testing, which has the responsibility to: - aid enquirers to understand the text; - presen
4、t to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; - monitor related intemationai and European developments and promuigate them in the UK A list of organizations represented on this committee can be obtained on re
5、quest to its secretary. Cross-references The Britkh 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“ faciiity of
6、the BSI Standards Electronic 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. Su
7、mmary of pages “his document comprises a front cover, an inside front cover, the EN title page, pages 2 to 10, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. ISBN O 580 35165 3 STDmBSI BS EN 12544-3-ENGL 1777 m
8、lb24bh7 081848Y T7L m EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 125443 September 1999 ICs 19.100 English version Non-destructive testing - Measurement and evaluation of the X-ray tube voltage - Part 3: Spectrometric method Essais non-destructifs - Mesurage et evaluation de la tension des
9、tubes radiognes - Partie 3: Mthode spectromtrique Zerstrungsfreie Prfung - Messung und Auswertung i er Rontgenrhrenspannung - Teil 3: Spektrometer-Verfahren This European Standard was approved by CEN on 16 August 1999. CEN members are bound to comply with the CENICENELEC Internal Regulations which s
10、tipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning sich national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standar
11、d exists in three official versions (English, French, German). 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
12、 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 FR NORMUNG COMITE EUROPEN DE NORMALISA
13、TION 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 12544-3:1999 E Page 2 EN 12544-3: 1999 Contents Page Foreword 3 Introduction . 4 1 Scope . 4 2 Definitions . 4 3 T
14、est method . 4 4 Test report 8 Annex A (informative) Selection of filters . . . . . . . . . . . . . . . . . . 1 O O BSI 12-1999 - STD-BSI BS EN 12544-3-ENGL 1797 Lb24bb4 UL48b Ab4 I Page 3 EN 12544-3:1999 Foreword This European Standard has been prepared by Technical Committee CENTTG 138 “Non-destru
15、ctive 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 March 2000, and conflicting national standards shall be withdrawn at the latest by March
16、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, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway
17、, Portugal, Spain, Sweden, Switzerland and the United Kingdom. In the framework of its scope, Technical Committee CENTTC 138 entrusted CEN/TC 138NVG 1 “Ionizing radiation“ with preparing the following standard: EN 12544-3, Non-destructive testing - Measurement and evaluation of the X-ray tube voltag
18、e - Part 3: Spectrometric method. EN 12544-3 is a pari of series of European Standards; the other parts are the following: EN 12544-1, Non-destructive testing - Measurement and evaluation of the X-ray tube voltage - Part i: Voltage divider method. EN 12544-2, Non-destructive testing - Measurement an
19、d evaluation of the X-ray tube voltage - Part 2: Constancy check by the thick filter method. O BSI 12-1999 STD=BSI BS EN 32544-3-ENGL 3999 Lb2LfbbS 0838487 7TO Page 4 EN 12544-3:1999 Introduction In order to cover the different requirements for the measurement of the X-ray tube voltage, three differ
20、ent methods are described in EN 12544-1 to EN 12544-3. The voltage divider method (EN 12544-1) enables a direct and absolute measurement of the average high voltage of constant potential X-ray systems on the secondary side of the high voltage generator. The thick filter method (EN 12544-2) describes
21、 a constancy check. This method is recommended for the regular stability check of an X-ray system. The spectrometric method (EN 12544-3) is a procedure for non-invasive measurement of the X-ray tube voltage using the energy spectrum of the X-rays. This method can be applied for all X-ray systems and
22、 is the recommended method whenever the voltage divider method is not applicable, e.g. in case of tank units where it is not possible to connect the voltage divider device. 1 Scope This standard specifies the test method for a non-invasive measurement of X-ray tube voltages using the energy spectrum
23、 of X-rays (spectrometric method). It covers the voltage range from 10 kV to 500 kV. The intention is to check the correspondence of the actual voltage with the indicated value on the control panel of the X-ray unit. It is intended to measure the maximum energy only and not the complete X-ray spectr
24、um. The procedure is applicable for tank type and constant potential X-ray units. 2 Definitions For the purposes of this standard, the following definitions apply: 2.1 Energy dispersive photon detector A photon detector, e.g. Ge based detector, which responds to incident photons with electric pulses
25、, whose amplitude are a measure for the energy of the photons. 2.2 Multi channel analyser An electronic device which is capable of sorting incoming electric pulses according to their amplitude. NOTE or channel is increased by one if a pulse occurs with the corresponding amplitude. The pulses are sor
26、ted into storage registers or channels in such a way that the contents of a register 2.3 Energy spectrum The graphical representation of the contents of the channels versus the energy. 2.4 Pile-up Effect of two or more pulses which are too close to each other and which causes their amplitude to be a
27、dded in the spectrum. 3 Test method 3.1 Principle An energy dispersive photon detector is located in the collimated direct beam of the X-ray tube under test (figure 1). The output pulses of the detector are counted and analysed by a multichannel analyser. O BSI 12-1999 STD-BSI BS EN 12544-3-ENGL 177
28、7 Lb24bb7 UBLB488 637 E Page 5 EN 12544-3: 1999 / 1 5 detector 1 Collimator and additional lead shielding 2 Filter 3 X-ray tube 4 Tube housing 5 Lead shielding 6 Pulse output to amplifier and multichannel analyser Figure 1 : Configuration for energy measurements 3.2 Equipment The following equipment
29、 is required for the measurements: 3.2.1 Detector Its energy range shall be at least 20 ?AO higher than the highest expected maximum energy. The energy resolution shall be about 1 keV full width at half maximum. For ease of filtering and shielding a detector with low efficiency but with sufficient r
30、esolution shall be chosen, as X-ray tubes usually produce sufficiently high dose rate. In order to allow as far as possible only direct radiation to hit the detector, the detector shall be carefully shielded with highly absorbing materials against leakage and scattered radiation. 3.2.2 Filters In or
31、der to attenuate the soft radiation, filters of AI, Fe, Cu, Pb or W shall be used (see annex A). The measurement of the maximum energy may be disturbed by the K-edge and the characteristic lines of a filter. Therefore, filter materials above the given value Umin according to table 1 shall be used: O
32、 BSI 12-1999 Page 6 EN 12544-3:1999 Filter Table 1 - Minimum voltages for some filter materials b) the X-ray system under inspection (identification number and type); c) X-ray parameters: voltage (kV), current (mA) and the selected focal spot size, also the nominal voltage and the maximum current; d
33、) type and size of the collimator; e) thickness and material of filter; 9 type and identification of detector and spectrometer; g) distances between tube, filters and detector; h) the date of the measurement; O BSI 12-1 999 Page 9 EN 12W-3:I 999 i) the measured value of the maximum energy; j) the di
34、fference between the measured and the nominal value of the maximum energy; k) name and signature of operator. O BSI 12-1999 Page 10 EN 12544-3: I999 80 kV 120 kV 160 kV 200 kV 300 kV 400 kV Annex A (informative) 3 mmFe 6 mmFe 10 mmFe 13 mm Fe 22 mmFe 38 mmFe Selection of filters In order to provide
35、a help concerning the selection of filters, this annex shows proposed filters, thicknesses drike, for different voltages U. These values ensure a sufficient absorption of the soft radiation, thus enabling a good measurement of the limiting energy according to figure 3. 20 kV I 1 mmAl I 40 kV 1 mmFe
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