1、January 2012 Translation by DIN-Sprachendienst.English price group 10No part of this translation 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).IC
2、S 19.100!$y+O“1860844www.din.deDDIN EN 16016-4Non destructive testing Radiation methods - Computed tomography Part 4: QualificationEnglish translation of DIN EN 16016-4:2012-01Zerstrungsfreie Prfung Durchstrahlungsverfahren - Computertomografie Teil 4: QualifizierungEnglische bersetzung von DIN EN 1
3、6016-4:2012-01Essais non destructifs Mthodes par rayonnements - Tomographie numrise Partie 4: QualificationTraduction anglaise de DIN EN 16016-4:2012-01www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.1601.12 DIN EN 16016-4:2012-01
4、2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee CEN/TC 138 “Non-destructive testing” (Secretatariat: AFNOR, France). The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Sta
5、ndards Committee), Working Committee NA 062-08-22 AA Durchstrahlungsprfung und Strahlenschutz. EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16016-4 August 2011 ICS 19.100 English Version Non destructive testing - Radiation methods - Computed tomography - Part 4: Qualification Essais non dest
6、ructifs - Mthodes par rayonnements - Tomographie numrise - Partie 4 : Qualification Zerstrungsfreie Prfung - Durchstrahlungsverfahren - Computertomografie - Teil 4: Qualifizierung This European Standard was approved by CEN on 29 July 2011. CEN members are bound to comply with the CEN/CENELEC Interna
7、l Regulations 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 CEN-CENELEC Management Centre or to any CE
8、N member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versi
9、ons. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slo
10、venia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN
11、national Members. Ref. No. EN 16016-4:2011: EEN 16016-4:2011 (E) 2 Contents Page Foreword 3Introduction .41 Scope 52 Normative references 53 Terms and definitions .54 Qualification of the inspection .54.1 General 54.2 Qualification of defect testing 54.2.1 General 54.2.2 Quality feature 54.2.3 Featu
12、re detectability/test system/system parameterisation .64.2.4 Verification of suitability .74.2.5 Consistency check 74.2.6 Documentation .74.3 Qualification of dimensional testing 84.3.1 General 84.3.2 Test and measurement task .84.3.3 Dimensional testing/test system/system parameterisation 84.3.4 De
13、gree of accuracy 94.3.5 Consistency check 94.3.6 Documentation .95 Qualification of the CT system .95.1 General 95.2 Integral overall system test . 105.3 Checking the system components . 105.3.1 General . 105.3.2 Manipulation system 105.3.3 Image scale 105.3.4 Beam axis perpendicularity . 105.3.5 Tu
14、be focal spot . 105.3.6 Tube stability . 105.3.7 Detector . 115.3.8 Reconstruction 115.3.9 Visualisation 115.4 Documentation 116 Example of CT system resolution evaluation methods 116.1 Pre-amble . 116.2 Acquisition parameters 126.3 Recommendations for creating reference objects 126.4 Density resolu
15、tion measurement method 126.4.1 General . 126.4.2 High energy reference object 136.4.3 Low energy reference object . 136.4.4 Experimental measurements . 13DIN EN 16016-4:2012-01 EN 16016-4:2011 (E) 3 Foreword This document (EN 16016-4:2011) 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 2012, and conflicting national standards shall be withdrawn at the latest by
17、 February 2012. 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. EN 16016 consists of the following parts: Non destructive testing Radi
18、ation methods Computed tomography Part 1: Terminology; Non destructive testing Radiation methods Computed tomography Part 2: Principle, equipment and samples; Non destructive testing Radiation methods Computed tomography Part 3: Operation and interpretation; Non destructive testing Radiation methods
19、 Computed tomography Part 4: Qualification. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France
20、, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 16016-4:2012-01 EN 16016-4:2011 (E) 4 Introduction This document gives guidelines f
21、or the general principles of X-ray computed tomography (CT) applicable to industrial imaging (in the context of this standard, industrial means non-medical applications); it also gives a consistent set of CT performance parameter definitions, including how these performance parameters relate to CT s
22、ystem specifications. This document deals with computed axial tomography and excludes other types of tomography such as translational tomography and tomosynthesis. DIN EN 16016-4:2012-01 EN 16016-4:2011 (E) 5 1 Scope This European Standard specifies guidelines for the qualification of the performanc
23、e of a CT system with respect to various inspection tasks. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (in
24、cluding any amendments) applies. EN 16016-1:2011, Non destructive testing Radiation method Computed tomography Part 1: Terminology EN 16016-3:2011, Non destructive testing Radiation methods Computed tomography Part 3: Operation and interpretation 3 Terms and definitions For the purposes of this docu
25、ment, the terms and definitions given in EN 16016-1:2011 apply. 4 Qualification of the inspection 4.1 General CT is used in industry both for defect testing and dimensional testing and measurement. Since CT does not directly provide measurement of desired quantities such as, for example, pore size o
26、r wall thickness, these quantities must be derived from the X-ray linear attenuation data represented by the CT grey values. The detectability of features and the degree of accuracy required depend on the inspection task, the specification of the available test equipment and the analysis and evaluat
27、ion methods used. When determination of such quantities is required, a special task-specific qualification test of the CT system is required. The qualification measures are described in 4.2 and 4.3. The qualification should be carried out by trained personnel. 4.2 Qualification of defect testing 4.2
28、.1 General Under test qualification, the suitability of the CT inspection technique for measuring a quantity to the required precision should be verified. The following steps described are typical of those for the successful verification of the suitability of CT for industrial applications. 4.2.2 Qu
29、ality feature Typical quantities to be measured are the sizes of pores, cavities, cracks, inclusions, contaminants as well as studies of the material distribution and the assembly and installation position of components. Because the test sample and the type, position and size of the features to be d
30、etected determine the properties of a CT system to be used, information such as the following should be known: a) test object : 1) dimensions; DIN EN 16016-4:2012-01 EN 16016-4:2011 (E) 6 2) weight; 3) materials; 4) path length to be X-rayed in the material; b) test feature: 1) type; 2) position; 3)
31、 size; 4) distribution, frequency; c) feature detectability: 1) limiting defect; 2) limiting feature. Since the feature detectability strongly influences the specification and therefore the cost of a CT system, special attention must be taken when defining the sensitivity of the tests required. If,
32、due to missing information, no limiting values for features are defined, it is recommended that the best possible sensitivity is used for the specific method and CT system and the attained feature detectability is verified using, for example, destructive tests. 4.2.3 Feature detectability/test syste
33、m/system parameterisation The usability of the CT system and the selection of system parameters are determined by the requirements for feature detectability. Typical variables are: a) spatial resolution: 1) overall spatial resolution of the CT image; 2) scan geometry; 3) detector spatial resolution;
34、 4) focal spot size of radiation source; b) contrast resolution: 1) overall contrast resolution of the CT image; 2) detector settings; 3) tube voltage; 4) tube current; c) reconstruction/visualisation: 1) number of projections; 2) CT grey value dynamic range of the reconstruction or visualisation; D
35、IN EN 16016-4:2012-01 EN 16016-4:2011 (E) 7 3) CT image size in X, Y and Z axes. CT system set-up and image quality parameters are described in EN 16016-3:2011, 4.1 and 5.1. 4.2.4 Verification of suitability 4.2.4.1 General A reliable statement on the defect detection sensitivity and the defect dete
36、ctability of the CT system used in a test shall be made by stating the degree of accuracy of the test required (tolerance, degree of fluctuation). Several alternative procedures are described in the following. 4.2.4.2 Reference samples with natural defects If a reference sample with a known defect i
37、s available, inspection of this sample is carried out and the detectability is stated after the test has been done. If a reference sample with unquantified defects is available, inspection of this part is carried out and the defect detectability is stated using a counter-check, using, for example, a
38、 destructive test after the CT scan has been done. 4.2.4.3 Reference sample with synthetic defect If the test feature can be simulated using a synthetic defect, for example, a hole, the defect detectability verification can take place similar to the previous section. 4.2.4.4 Reference sample without
39、 specifications If no specifications are available for the reference sample status and a counter-check is not possible, the test is carried out using the system sensitivity. Sample structures like, for example, wall thicknesses and external dimensional measurements can be used for estimating the def
40、ect detectability. Alternatively, reference samples like, for example, wires or spheres of known dimensions can be used. 4.2.5 Consistency check The CT scan requires several very complex process steps for which the error sources cannot always be excluded. After the scan, the following can be used to
41、 trace the possible error sources: reconstruction: size, CT slice positions, possible artefacts ; CT image scale; sinogram (CT grey value and curve progress) or CT projection sequence (comparison between projections, image quality of the projections, intensity changes); system status (error messages
42、). Where errors occur, either they shall be corrected or their causes shall be eliminated and the test repeated. 4.2.6 Documentation In the qualification report, the relevant parameters and results of the qualification steps are to be described and presented. The CT images are to be archived for a p
43、eriod which is to be agreed with the end-user. The test parameters are to be archived so that an identical test procedure is possible in the case of recurrent test parts and features. DIN EN 16016-4:2012-01 EN 16016-4:2011 (E) 8 4.3 Qualification of dimensional testing 4.3.1 General CT inspection pr
44、ovides information about the 3D structure of a sample from which surface and geometry data can be derived. Because these data are based on X-ray-physical absorption differences at the contour transitions, small differences in measured values may arise compared to classical tactile or optical measuri
45、ng procedures. In the following sections, those CT scan parameters which influence the results will be described, together with those process steps which affect the accuracy of the results. 4.3.2 Test and measurement task Dimensional measurement tasks include the measurement of single dimensions in
46、the test object, wall thickness measurements, surface extraction, volume extraction or nominal-actual comparisons. The required measurement precision is to be defined for every task and if necessary for different parts of the sample. 4.3.3 Dimensional testing/test system/system parameterisation The
47、degree of accuracy attainable depends on the test object, the limitations of X-ray physics and the subsequent data handling. An initial estimation of the degree of accuracy of a CT-based dimensional measurement can take place with the following parameters: a) spatial resolution in the test object: 1
48、) dimensions; 2) geometric magnification, voxel size; 3) detector resolution; 4) focal spot; b) X-ray penetration of test object : 1) material; 2) maximal wall thickness to be X-rayed; 3) contrast resolution; c) 3D component data : 1) original CT image voxel size; 2) extraction steps and quality; 3) further processing steps
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