EN 17119-2018 Non-destructive testing - Thermographic testing - Active thermography.pdf

1、BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06Non-destructive testing - Thermographic testing - Active thermographyBS EN 17119:2018EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 17119 August 2018 ICS 19.100 English Version Non-destructive testing - Thermograp

2、hic testing - Active thermography Essais non destructifs - Analyse thermographique - Thermographie active Zerstrungsfreie Prfung - Thermografische Prfung - Aktive Thermografie This European Standard was approved by CEN on 20 April 2018. CEN members are bound to comply with the CEN/CENELEC Internal R

3、egulations 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 m

4、ember. 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

5、 CEN members 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, Pola

6、nd, Portugal, Romania, Serbia, 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: Rue de la Science 23, B-1040 Brussels 2018 CEN All rights of e

7、xploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 17119:2018 ENational forewordThis British Standard is the UK implementation of EN 17119:2018.The UK participation in its preparation was entrusted to Technical Committee WEE/46, Non-destructive testing.

8、A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2018 Published by BSI Standa

9、rds Limited 2018ISBN 978 0 580 97767 1ICS 19.100Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2018.Amendments/corrigenda issued since publicationDat

10、e Text affectedBRITISH STANDARDBS EN 17119:2018EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 17119 August 2018 ICS 19.100 English Version Non-destructive testing - Thermographic testing - Active thermography Essais non destructifs - Analyse thermographique - Thermographie active Zerstrungsfre

11、ie Prfung - Thermografische Prfung - Aktive Thermografie This European Standard was approved by CEN on 20 April 2018. 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 a

12、ny 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. This European Standard exists in three official versions (English, French, German). A version in any other langu

13、age 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 members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark

14、 Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMM

15、ITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels 2018 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 17119:2018 EBS EN 171

16、19:2018EN 17119:2018 (E) 2 Contents Page European foreword . 3 1 Scope 4 2 Normative references 4 3 Terms and definitions . 4 4 Techniques of data acquisition 6 4.1 General 6 4.2 Types of temporal excitation 7 4.2.1 Pulse thermography . 7 4.2.2 Step thermography . 7 4.2.3 Lock-in thermography . 7 4.

17、3 Types of spatial excitation . 7 4.3.1 Local excitation 7 4.3.2 Two-dimensional excitation . 7 4.3.3 Excitation of the whole volume 7 4.4 Typical configurations of active thermography . 8 4.4.1 Reflection and transmission configurations . 8 4.4.2 Static and dynamic configuration 8 5 Techniques of d

18、ata processing and analysis . 9 5.1 General 9 5.2 Data processing in time domain 9 5.3 Data processing in frequency domain . 9 5.4 Data analysis 10 6 Qualification of personnel 11 7 Specifications to the test system . 11 8 Performance of testing . 12 9 Test report 12 Annex A (informative) Excitation

19、 techniques of thermography 13 BS EN 17119:2018EN 17119:2018 (E) 3 European foreword This document (EN 17119:2018) 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

20、standard, either by publication of an identical text or by endorsement, at the latest by February 2019, and conflicting national standards shall be withdrawn at the latest by February 2019. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent

21、rights. CEN shall not be held responsible for identifying any or all such patent rights. According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czec

22、h 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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United

23、 Kingdom. BS EN 17119:2018EN 17119:2018 (E) 4 1 Scope This document defines the procedures for non-destructive testing using active thermography. These testing procedures can be applied to different materials (e.g. composites, metals and coatings) and are appointed, but not limited to the: detection

24、 of discontinuities (e.g. voids, cracks, inclusions, delaminations); determination of layer or part thicknesses; determination and comparison of thermophysical properties. This standard is describing data acquisition and analysis principles for active thermography and is giving an informative guidel

25、ine for appropriate selection of the excitation source. Acceptance criteria are not defined in this standard. Active thermography is applied in industrial production (e.g. compound materials, vehicle parts, engine parts, power plant parts, joining technology, electronic devices) and in maintenance a

26、nd repair (e.g. aerospace, power plants, civil engineering). 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated referen

27、ces, the latest edition of the referenced document (including any amendments) applies. EN 16714-1, Non-destructive testing - Thermographic testing - Part 1: General principles EN 16714-2, Non-destructive testing - Thermographic testing - Part 2: Equipment EN 16714-3, Non-destructive testing - Thermo

28、graphic testing - Part 3: Terms and definitions EN 15042-2:2006, Thickness measurement of coatings and characterization of surfaces with surface waves - Part 2: Guide to the thickness measurement of coatings by photothermic method CEN/TR 14748, Non-destructive testing - Methodology for qualification

29、 of non-destructive tests 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 16714-3, EN 15042-2:2006 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: availabl

30、e at http:/www.electropedia.org/ ISO Online browsing platform: available at http:/www.iso.org/obp 3.1 amplitude image image of the spatial distribution of the amount of radiation emitted by the body at a frequency f 3.2 derivative image image of the spatial distribution of the first or higher order

31、temporal derivative of the temperature response to excitation BS EN 17119:2018EN 17119:2018 (E) 5 3.3 dynamic temperature contrast local distribution of the temporally varying temperature difference relative to a reference temperature 3.4 lock-in thermography modulated thermography energy is introdu

32、ced periodically in time at the modulation frequency fLI, e.g., in a sinusoidal manner 3.5 phase image image of the spatial distribution of the temporal delay of the temperature response at a frequency f 3.6 pulse thermography energy is introduced by means of a short pulse that can be considered as

33、a Dirac pulse 3.7 step thermography energy source is switched on or/and off for a defined time during which thermal diffusion can occur 3.8 thermal diffusion length characteristic length of heat diffusion after pulsed or during periodic introduction of energy at a frequency f = sqrt (/f) 3.9 thermal

34、 diffusivity represents the temporal and spatial diffusion of thermal energy (heat) inside a body Note 1 to entry: In thermodynamics, a is used as symbol. Note 2 to entry: Depending on the material might not be isotropic. 3.10 thermal effusivity e represents the temperature change of a material as a

35、 reaction to a transient input of energy Note 1 to entry: In thermodynamics, b is used as symbol. Note 2 to entry: Depending on the material e might not be isotropic. BS EN 17119:2018EN 17119:2018 (E) 6 3.11 thermal reflection coefficient Rcmeasure for the reflection of thermal waves (related to the

36、 model of thermal diffusion waves) at the interface between two layers having different thermal effusivities e1and e2Rc= (e1 e2) / (e1+ e2) 3.12 thermal transmission coefficient Tcmeasure for the transmission of thermal waves (related to the model of thermal diffusion waves) at the interface between

37、 two layers having different thermal effusivities e1and e2Tc= 2 e1/ (e1+ e2) 4 Techniques of data acquisition 4.1 General In active thermography, an additional artificial or natural energy source is applied introducing a time dependent heat flux inside the test specimen. This is only done for the pu

38、rpose of testing (principle see Figure 1). Figure 1 Principle of active thermography Thermal excitation can be generated in the test object with different energy sources based on various effects such as: absorption of optical radiation (e.g. light or infrared) and/or microwaves; electromagnetic indu

39、ction and/or electric current; conversion of mechanical waves (e.g. ultrasonic); convection (e.g. hot/cold air); BS EN 17119:2018EN 17119:2018 (E) 7 conduction (e.g. hot blanket). Discontinuities inside the test object may affect the heat generation and propagation process and become indirectly visi

40、ble by recording the emitted radiation with an infrared camera (IR camera). A controller can provide synchronization between energy source and image recording. Generally, a sequence consisting of a number of images is recorded, which may be analysed subsequently. 4.2 Types of temporal excitation 4.2

41、1 Pulse thermography For excitation, an energy source is used that provides a short pulse (e.g. flash lamp or a laser). Short means that it can be considered as a Dirac pulse and that the duration of the pulse is significantly less than the time needed for recording a thermal signature of the defec

42、ts or of the rear side of the layer. The image sequence may be analysed in time domain, as described in 5.2, or in frequency domain, as described in 5.3. 4.2.2 Step thermography For excitation, an energy source (e.g. halogen lamp or induction) is switched on or/and off at a particular time. Contrary

43、 to pulse thermography, the thermal signature of the defects or of the rear side of the layer already appears during excitation. The image sequence may be analysed in time domain, as described in 5.2, or in frequency domain, as described in 5.3. 4.2.3 Lock-in thermography For excitation, the energy

44、source (e.g. halogen lamp or ultrasound) used is periodically modulated in intensity. The signal shape used for excitation can be e.g. a sinus or a square. The selection of the appropriate modulation frequency range depends mainly on the depth range to be investigated and is related to the thermal d

45、iffusion length. Each pixel of the thermal image sequence is correlated in frequency domain with the excitation signal or a reference. This procedure should be performed during a sufficient time of observation of typically several modulation periods. The image sequence should be analysed in frequenc

46、y domain, as described in 5.3. 4.3 Types of spatial excitation 4.3.1 Local excitation A local excitation (e.g. by applying a laser spot) is used to generate a three dimensional heat diffusion within the field of view of the IR camera. Defects with all orientations to the surface can be located. Line

47、ar excitation sources can also be used. 4.3.2 Two-dimensional excitation A two-dimensional excitation (e.g. by using halogen lamps or an array of cold air guns) is used in order to homogeneously heat or cool the surface of the test object. As heat diffuses perpendicular to the surface mainly defects

48、 oriented parallel to the surface can be located. 4.3.3 Excitation of the whole volume The whole volume of the test object is excited in order to induce dissipative processes at the location of defects. For the detection of cracks, e.g. power ultrasonic excitation can be used and for the detection o

49、f moisture, e.g. microwave excitation can be used. BS EN 17119:2018EN 17119:2018 (E) 8 4.4 Typical configurations of active thermography 4.4.1 Reflection and transmission configurations In reflection configuration, excitation source and IR camera are placed on the same side of the test object (see Figure 2 a). Therefore, it has to be considered that the excitation source also might emit radiation in the spectral domain of sensitivity of the IR camera. In transmission configuration, excitation source and IR camera are positioned on op