1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58with storage phosphor imaging plates Part 1: Classification of systemsThe European Standard EN 1478
2、4-1:2005 has the status of a British StandardICS 19.100Non-destructive testing Industrial computed radiography BRITISH STANDARDBS EN 14784-1:2005BS EN 14784-1:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2005 BSI 30 Septem
3、ber 2005ISBN 0 580 46654 XCross-referencesThe British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BS
4、I Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pag
5、esThis document comprises a front cover, an inside front cover, the EN title page, pages 2 to 27 and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA list of organizations represent
6、ed on this committee can be obtained on request to its secretary.enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.National forewordThis British Standard is the official Engl
7、ish language version of EN 14784-1:2005.The UK participation in its preparation was entrusted to Technical Committee WEE/46, Non-destructive testing, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any EUROPEAN STANDA
8、RDNORME EUROPENNEEUROPISCHE NORMEN 14784-1August 2005ICS 19.100English VersionNon-destructive testing - Industrial computed radiography withstorage phosphor imaging plates - Part 1: Classification ofsystemsEssais non destructifs - Radiographie industriellenumrise avec des plaques-images au phosphore
9、 - Partie1 : Classification des systmesZerstrungsfreie Prfung - Industrielle Computer-Radiographie mit Phosphor-Speicherfolien - Teil 1:Klassifizierung der SystemeThis European Standard was approved by CEN on 1 July 2005.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which
10、 stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard
11、 exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards b
12、odies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR
13、 STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2005 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14784-1:2005: EEN 14784-1:2005 (E) 2 Contents Pag
14、e Foreword3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Personnel qualification .6 5 CR quality indicators.6 6 Procedure for quantitative measurement of image quality parameters 8 7 CR System Classification and Interpretation of Results .15 Annex A (informative) Example for IIPxm
15、easurement .18 Annex B (informative) Example of CR test phantom .22 Annex C (informative) Guidance for application of various tests and test methods .25 Bibliography 27 EN 14784-1:2005 (E) 3 Foreword This European Standard (EN 14784-1:2005) has been prepared by Technical Committee CEN/TC 138 “Non-de
16、structive 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 February 2006, and conflicting national standards shall be withdrawn at the latest by
17、 February 2006. EN 14784 comprises a series of European Standards for industrial computed radiography with storage phosphor imaging plates which is made up of the following: EN 14784-1 Non-destructive testing Industrial computed radiography with storage phosphor imaging plates Part 1: Classification
18、 of systems EN 14784-2 Non-destructive testing Industrial computed radiography with storage phosphor imaging plates Part 2: General principles for testing of metallic materials using X-rays and gamma rays According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
19、following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, S
20、weden, Switzerland and United Kingdom. EN 14784-1:2005 (E) 4 1 Scope This European Standard specifies fundamental parameters of computed radiography systems with the aim of enabling satisfactory and repeatable results to be obtained economically. The techniques are based both on fundamental theory a
21、nd test measurements. This document specifies the performance of computed radiography (CR) systems and the measurement of the corresponding parameters for the system scanner and storage phosphor imaging plate (IP). It describes the classification of these systems in combination with specified metal
22、screens for industrial radiography. It is intended to ensure that the quality of images - as far as this is influenced by the scanner-IP system - is in conformity with the requirements of Part 2 of this document. The document relates to the requirements of film radiography defined in EN 584-1 and IS
23、O 11699-1. This European Standard defines system tests at different levels. More complicated tests are described, which allow the determination of exact system parameters. They can be used to classify the systems of different suppliers and make them comparable for users. These tests are specified as
24、 manufacturer tests. Some of them require special tools, which are usually not available in user laboratories. Therefore, simpler user tests are also described, which are designed for a fast test of the quality of CR systems and long term stability. There are several factors affecting the quality of
25、 a CR image including geometrical un-sharpness, signal/noise ratio, scatter and contrast sensitivity. There are several additional factors (e.g. scanning parameters), which affect the accurate reading of images on exposed IPs using an optical scanner. The quality factors can be determined most accur
26、ately by the manufacturer tests as described in this document. Individual test targets, which are recommended for practical user tests, are described for quality assurance. These tests can be carried out either separately or by the use of the CR Phantom (Annex B). This CR Phantom incorporates many o
27、f the basic quality assessment methods and those associated with the correct functioning of a CR system, including the scanner, for reading exposed plates and in correctly erasing IPs for future use of each plate. The CR System classes in this document do not refer to any particular manufacturers Im
28、aging Plates. A CR system class results from the use of a particular imaging plate together with the exposure conditions particularly total exposure the scanner type and the scanning parameters. 2 Normative references The following referenced documents are indispensable for the application of this E
29、uropean standard. For dated references, only the edition cited applies. 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), determ
30、ination of image unsharpness value. EN 584-1, Non destructive testing Industrial radiographic film Part 1: Classification of film systems for industrial radiography. 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply: 3.1 computed radiograph
31、y system (CR system) complete system of a storage phosphor imaging plate (IP) and corresponding read-out unit (scanner or reader) and system software, which converts the information of the IP into a digital image EN 14784-1:2005 (E) 5 3.2 computed radiography system class particular group of storage
32、 phosphor imaging plate systems, which is characterised by a SNR (Signal-to-Noise Ratio) range shown in Table 1 and by a certain basic spatial resolution value (e.g. derived from duplex wire IQI) in a specified exposure range. 3.3 CEN speed SCENdefines the speed of CR systems and is calculated from
33、the reciprocal dose value, measured in Grays, which is necessary to obtain a specified minimum SNR of a CR system 3.4 signal-to-noise ratio (SNR) quotient of mean value of the linearised signal intensity and standard deviation of the noise at this signal intensity. The SNR depends on the radiation d
34、ose and the CR system properties. 3.5 modulation transfer function (MTF) normalised Magnitude of the Fourier-transform (FT) of the differentiated edge spread function (ESF) of the linearised PSL (photo stimulated luminescence) intensity, measured perpendicular to a sharp edge. MTF describes the cont
35、rast transmission as a function of the object size. MTF characterises the un-sharpness of the CR system in dependence on the scanning system and IP-type. 3.6 CR phantom device containing an arrangement of test targets to evaluate the quality of a CR system - as well as monitoring the quality of the
36、chosen system 3.7 laser beam jitter lack of smooth movement of the plate laser-scanning device, causing lines in the image consisting of a series of steps 3.8 scanner slippage slipping of an IP in a scanner transport system resulting in fluctuation of intensity of horizontal image lines 3.9 aliasing
37、 pre-sampled high spatial frequency signals beyond the Nyquist frequency (given by the pixel distance) reflected back into the image at lower spatial frequencies 3.10 gain/amplification opto-electrical gain setting of the scanning system 3.11 linearised signal intensity numerical signal value of a p
38、icture element (pixel) of the digital image, which is proportional to the radiation dose. The linearised signal intensity is zero, if the radiation dose is zero. 3.12 basic spatial resolution read-out value of un-sharpness measured with duplex wire IQI according to EN 462-5 divided by 2 as effective
39、 pixel size of CR system EN 14784-1:2005 (E) 6 4 Personnel qualification It is assumed that industrial computed radiography is performed by qualified and capable personnel. In order to prove this qualification, it is recommended to certify the personnel according to EN 473 or ISO 9712. 5 CR quality
40、indicators 5.1 Description of CR quality indicators for user and manufacturer tests 5.1.1 General The following is a description of CR quality indicators, which will be identified by reference to this document. 5.1.2 Contrast sensitivity quality indicator The description of the selected contrast sen
41、sitivity targets corresponds to ASTM E1647-98a (see for details Annex B.4). 5.1.3 Duplex wire quality indicator The description of the duplex wire quality indicator corresponds to EN 462-5. The IQI shall be positioned at a 5angle to the direction of the scanned lines (fast scan direction) or the per
42、pendicular direction (slow scan direction). 5.1.4 Converging line pair quality indicator The target consist of 5 converging strips of lead (0,03 mm thickness) which can be used for spatial resolution test by reading the limit of recognisable line pairs. It shall cover a range from 1,5 to 20 line pai
43、rs per mm (lp/mm). Two quality indicators shall be used, one in direction of the scanned lines and the other one in the perpendicular direction. 5.1.5 Linearity quality indicators Rulers of high absorbing materials are located on the perimeter of the scanned range. Two quality indicators shall be us
44、ed, one in direction of the scanned lines and the other in the perpendicular direction. The scaling shall be at least in mm. 5.1.6 T-target This CR quality indicator consists of a thin plate of brass or copper ( 0,5 mm thick) with sharp edges. This plate is manufactured in a T-shape with 5 mm wide s
45、egments. The T should have a size of at least 50 mm 70 mm. It shall be aligned perpendicular and parallel respectively to the direction of the scanned lines (see Figure B.1). 5.1.7 Scanner slipping quality indicator It consists of a homogenous strip of aluminium of 0,5 mm thickness. It has a shape o
46、f a rectangle (see Figure B.1) and shall be aligned perpendicular and parallel respectively to the direction of the scanned lines. 5.1.8 Shading quality indicator Different shading quality indicators may be used. One type is based on the homogeneous exposure of an imaging plate (IP) with a thin Al-p
47、late (0,5 mm to 1,0 mm) above the IP. The exposure shall be made with low energy radiation (50 keV to 100 keV). EN 14784-1:2005 (E) 7 Another type is the shading quality indicator of the CR-test phantom (see Annex B). 5.1.9 Central beam alignment quality indicator (BAM-snail) The alignment quality i
48、ndicator consists of a roll (1,5 mm to 2,0 mm thick) of thin lead foil separated by a spacer of 0,1 mm to 0,2 mm of low absorbing material; (see Annex B.3). Honeycomb material may also be used. 5.2 Application procedures for CR quality indicators 5.2.1 General The CR quality indicators are designed
49、for fast evaluation of the quality of a CR system as well as for a periodical quality control. Annex C gives a guidance for application of various tests and test methods. 5.2.2 Exposure of CR quality indicators (user test) The CR quality indicators should be positioned in a special arrangement as described in Annex B in the CR phantom. The CR quality indicators can be applied separately or all together in the CR phantom. The selected set of CR quality indicators or the CR phantom is placed on the cassette, whic
