BS EN 16714-1-2016 Non-destructive testing Thermographic testing General principles《无损检验 温度记录试验 总则》.pdf

1、BS EN 16714-1:2016Non-destructive testing Thermographic testingPart 1: General principlesBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS EN 16714-1:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 16714-1:2016.The UK parti

2、cipation in its preparation was entrusted to TechnicalCommittee WEE/46, Non-destructive testing.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsib

3、le for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 85396 8ICS 19.100Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy

4、and Strategy Committee on 31 August 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS EN 16714-1:2016EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16714-1 August 2016 ICS 19.100 English Version Non-destructive testing - Thermographic testing - Part 1: General p

5、rinciples Essais non destructifs - Analyses thermographiques - Partie 1: Principes gnraux Zerstrungsfreie Prfung - Thermografische Prfung - Teil 1: Allgemeine Grundlagen This European Standard was approved by CEN on 25 June 2016. CEN members are bound to comply with the CEN/CENELEC Internal Regulati

6、ons 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 CEN member.

7、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 versions. CEN m

8、embers are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Por

9、tugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CEN All rights of exploitation in any

10、form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16714-1:2016 EBS EN 16714-1:2016EN 16714-1:2016 (E) 2 Contents Page European foreword . 3 1 Scope 4 2 Normative references 4 3 Terms and definitions . 4 4 Apparatus . 4 5 Preparation for testing 4 5.1 Test instruction 4 5

11、.2 Description of method . 4 5.3 Availability of test instruction and description of method 5 5.4 Preparation criteria . 5 5.5 Reference test specimens . 6 5.6 Apparatus check 6 5.7 Surface and emissivity . 6 6 Thermography procedures . 7 6.1 General 7 6.2 Passive thermography . 7 6.3 Active thermog

12、raphy . 7 6.4 Qualitative thermography . 8 6.5 Comparative thermography 8 6.6 Quantitative thermography. 8 7 Personnel qualifications and duties . 9 8 Evaluation 9 9 Test report . 9 10 Records 10 Bibliography . 11 BS EN 16714-1:2016EN 16714-1:2016 (E) 3 European foreword This document (EN 16714-1:20

13、16) has been prepared by Technical Committee CEN/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 February 2017, and con

14、flicting national standards shall be withdrawn at the latest by February 2017. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights. Non-destructive testin

15、g Thermographic testing consists of the following parts: Part 1: General principles Part 2: Equipment Part 3: Terms and definitions According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austri

16、a, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden,

17、 Switzerland, Turkey and the United Kingdom. BS EN 16714-1:2016EN 16714-1:2016 (E) 4 1 Scope This European Standard specifies the general principles for thermography of non-destructive testing. Thermographic testing is used for the detection and localization of discontinuities (e.g. cracks, delamina

18、tion and inclusions) in different materials (e.g. composites, metals and coatings). Usually a thermal stimulation is required. The choice of thermal stimulation depends on the application (e.g. type of material, geometry of test object, type of defects to be determined). Acceptance criteria are not

19、defined in this standard. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced doc

20、ument (including any amendments) applies. EN 1330-1, Non destructive testing - Terminology - Part 1: List of general terms EN 1330-2, Non destructive testing - Terminology - Part 2: Terms common to the non-destructive testing methods EN 16714-2, Non-destructive testing Thermographic testing Part 2:

21、Equipment EN 16714-3, Non-destructive testing Thermographic testing Part 3: Terms and definitions EN ISO 9712, Non-destructive testing - Qualification and certification of NDT personnel (ISO 9712:2012) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 1

22、330-1, EN 1330-2 and EN 16714-3 apply. 4 Apparatus According to EN 16714-2. 5 Preparation for testing 5.1 Test instruction A test instruction shall be prepared that specifies the minimum test requirements relating to each of the items listed in 5.4. 5.2 Description of method If required, for example

23、 by a product standard or contract, a description of the method shall be prepared. BS EN 16714-1:2016EN 16714-1:2016 (E) 5 5.3 Availability of test instruction and description of method Copies of the test instruction and, if applicable, of the description of the method shall be made available to the

24、 responsible personnel. 5.4 Preparation criteria The following points shall be taken into account or stipulated in preparing for the test: a) position, accessibility and geometry of the objects under test; b) purpose of testing; c) scope of test; d) area to be tested; e) kind of expected inhomogenei

25、ties (e.g. geometry, orientation, depth, surface breaking or not); f) test requirements, especially those relating to: spatial resolution; temporal resolution; thermal resolution; measurement precision; g) apparatus, including: selection of appropriate energy source and its characteristic parameters

26、; selection of IR camera and its characteristic parameters; spatial set up of energy source, IR camera and test object; verification of test equipment (regarding proper working); h) test procedure including: optimization of the spatial set up (e.g. field of view, focusing, avoiding reflection); crit

27、eria of notation (e.g. size, location, number of indications); measurement parameters; i) ambient conditions at the time of testing; j) operational state of the objects under test at the time of testing; k) surface properties, such as emission, transmission and reflection, of the objects under test;

28、 l) personnel qualifications and duties (see Clause 7); m) scope of test report (see Clause 9). BS EN 16714-1:2016EN 16714-1:2016 (E) 6 5.5 Reference test specimens For controlling the set-up of the whole measurement system as well as the selected measurement parameters, at least one of three differ

29、ent kinds of reference test specimens shall be used: Type 1: Reference test specimen for calibration check and/or testing the measurement system; Type 2: Reference test specimen with artificial defects for quantification of detection sensitivity for a distinct type of material; Type 3: Reference tes

30、t specimen with natural defects for quantification of detection sensitivity for a distinct type of material (original test object). Reference test specimens of type 1 are used preliminary for testing single components as well as the whole measurement set-up (e.g. black body, large metal plate). Prio

31、r to and/or during testing, the proper function and, if required, calibration of the infrared camera has to be checked. For controlling the temperature calibration, a calibrated black body should be used at two different temperatures being relevant for the test. Deviations should not exceed the accu

32、racy of the actual calibration. Further function controls have to be performed according to EN 16714-2. If the energy is introduced by homogeneous radiation, the spatial homogeneity of the radiation source should be tested using e.g. a large blackened metal plate. Reference test specimens of type 2

33、include artificial defects like flat bottom holes, notches or step wedges with different geometry made of the same material as the object under test. Additionally, any anisotropic thermal material properties have to be considered, e.g. as for CFRP. For enabling unique defect identification as well a

34、s for evaluating the detection limits of the measurement system for these defects, several type 2 reference test specimens may be necessary to cover all of the expected defects. Reference test specimens of type 3 are real test specimens with natural defects as they are generated during the productio

35、n process or during the life of the part. Kind of material, geometry and surface condition are similar to those of the test objects. The defects should be characterized by any non-destructive method, e.g. computed tomography, ultrasonic testing. 5.6 Apparatus check Steps shall be taken to ensure tha

36、t the apparatus to be used for the test is operating correctly, i.e. in accordance with the technical specifications using one of the reference test specimens (see 5.5). Individual performance of each component can be checked by reference test specimen of type 1 and the global performance of the sys

37、tem using the test specimen of type 2 or 3. 5.7 Surface and emissivity The performance of temperature measurements on the object under test is influenced by the emissivity and irradiation coming from the surrounding environment, which has to be taken to account. In the case of objects with low emiss

38、ivity, i.e. with high reflectance or transmittance, a coating having high emissivity may be applied, if necessary. Type, thickness and further parameters of the coating have to be adapted to the application. This should be determined using a reference test specimen of type 2 or 3. BS EN 16714-1:2016

39、EN 16714-1:2016 (E) 7 6 Thermography procedures 6.1 General Thermographic testing can be performed actively or passively and evaluated qualitatively, comparatively or quantitatively (see Table 1). Table 1 Overview of thermographic procedures Procedure Excitation Active Passive Qualitative Examinatio

40、n of thermal patterns (radiation distribution) Comparative Differential quantities (e.g. , T) Differential quantities (e.g. T) Quantitative Absolute quantities (e.g. , T) Absolute quantities (e.g. T) To be successful, thermographic testing requires: choice of a camera with appropriate sensitivity an

41、d setting of the suitable measurement range; choice of a suitable image section for visually comparing the display with the undisturbed state; avoidance of reflections by choosing a suitable viewing angle; monitoring or minimizing interference due to external radiation sources, draughts and humidity

42、; choice of a lens capable of maintaining the required spatial resolution; careful focusing of the image; choice of suitable display settings for the temperature scale, contrast, brightness, colour range, etc. 6.2 Passive thermography Passive thermography uses only the heat flow due to the intrinsic

43、 heat of the object under test. Such heat includes both internally generated heat (e.g. in furnaces). Time dependent heat flows are usually not required, i.e. the information is included in one thermogram. Passive thermography is used for example in building (e.g. to locate moisture, thermal bridges

44、, leaks), for inspecting electrical and mechanical systems, in process and installation diagnostics. 6.3 Active thermography In active thermography, a non-stationary heat flow is generated in the object under test by natural or additional energy sources only for the purpose of thermographic testing.

45、 Exposure to such energy sources can take place on a single occasion, periodically or continuously. Several energy sources (e.g. sun radiation, light, ultrasound, hot and cold air, induction) can be used. They can be selected according to the application and requirements. The performance of the exci

46、tation shall be validated on a reference test specimen type 2 or 3. Examples for the excitation sources are given in EN 16714-2. Active thermography is used to detect defects or discontinuities (e.g. voids, disbonding, delamination, cracks, thickness variation) for example in industrial production a

47、nd maintenance (e.g. metallic or composite materials such as engine and machine components, joining technology). BS EN 16714-1:2016EN 16714-1:2016 (E) 8 Active thermography is subdivided, depending on the type of excitation, into: transient thermography (e.g. pulse thermography, step thermography) a

48、nd, modulation thermography (e.g. lock-in thermography, burst thermography) and, depending on the type of evaluation, into: phase-angle thermography or lock-in thermography (display of or ), time derivative related thermography (display of )ln()ln(tT) and, differential-temperature thermography (disp

49、lay of T or T). 6.4 Qualitative thermography This is a procedure in which the display of the radiation density or apparent temperature distribution over the surface of the object under test is adequate for an assessment of the test result. Typical examples of its application are the location of leaks in pipelines or containers or the visualization of the variation in floor heating or of a concealed framework structure. It is also used for locating delamination in laminated materials. 6.5 Comparat