BS EN 14127-2011 Non-destructive testing Ultrasonic thickness measurement《无损检测 超声波厚度测量》.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 14127:2011Non-destructive testing Ultrasonic thicknessmeasurementBS EN 14127:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 1412

2、7:2011. Itsupersedes BS EN 14127:2004 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee WEE/46, Non-destructive testing.A list of organizations represented on this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 i

3、nclude all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 71098 8ICS 19.100Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy a

4、nd Strategy Committee on 31 March 2011.Amendments issued since publicationDate Text affectedBS EN 14127:2011EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 14127 February 2011 ICS 19.100 Supersedes EN 14127:2004English Version Non-destructive testing - Ultrasonic thickness measurement Essais no

5、n destructifs - Mesurage de lpaisseur par ultrasons Zerstrungsfreie Prfung - Dickenmessung mit UltraschallThis European Standard was approved by CEN on 25 December 2010. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European

6、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. This European Standard exists in three official versions (En

7、glish, 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 members are the national standards bodies of Austria, Belgium

8、, 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, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITT

9、EE 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 national Members. Ref. No. EN 14127:2011: EBS EN 14127:2011EN 14127:20

10、11 (E) 2 Contents Page Foreword 41 Scope 52 Normative references 53 Terms and definitions . 54 Measurement modes . 55 General requirements 75.1 Instruments 75.2 Probes . 75.3 Couplant . 75.4 Reference blocks . 75.5 Test objects 75.6 Qualification of personnel 86 Application of the technique 86.1 Sur

11、face conditions and surface preparation 86.2 Technique . 86.2.1 General 86.2.2 Measurement during manufacture . 96.2.3 In-service measurement of residual wall thickness . 96.3 Selection of probe 96.4 Selection of instrument . 106.5 Materials different from the reference . 106.6 Special measuring con

12、ditions 106.6.1 General 106.6.2 Measurements at temperatures below 0 C 116.6.3 Measurements at elevated temperatures 116.6.4 Hazardous atmospheres . 117 Instrument setting 117.1 General 117.2 Methods 127.2.1 General 127.2.2 Digital thickness instruments . 127.2.3 A-scan Instruments . 127.3 Check of

13、settings . 138 Influence on accuracy . 148.1 Operational conditions 148.1.1 Surface conditions. 148.1.2 Surface temperature 148.1.3 Metallic coating 158.1.4 Non-metallic coating . 158.1.5 Geometry 168.2 Equipment 178.2.1 Resolution 178.2.2 Range 178.3 Evaluation of accuracy 188.3.1 General 188.3.2 I

14、nfluencing parameters . 188.3.3 Method of calculation 18BS EN 14127:2011EN 14127:2011 (E) 3 9 Influence of materials 189.1 General 189.2 Inhomogeneity . 189.3 Anisotropy 189.4 Attenuation . 189.5 Surface conditions 189.5.1 General 189.5.2 Contact surface 199.5.3 Reflecting surface 199.5.4 Corrosion

15、and erosion 2010 Test report 2010.1 General 2010.2 General information . 2010.3 Inspection data 21Annex A (informative) Corrosion in vessels and piping 22A.1 General 22A.2 Measurement of general corrosion 22A.2.1 Instrument 22A.2.2 Probes . 22A.2.3 Setting of the instrument 22A.2.4 Measuring . 23A.3

16、 Measurement of corrosion with pitting . 23A.3.1 Instrument 23A.3.2 Probes . 23A.3.3 Setting of the instrument 23A.3.4 Measuring . 23Annex B (informative) Instrument settings 29Annex C (informative) Parameters influencing accuracy 31C.1 Parameters influencing accuracy 31C.2 Methods of calculation 33

17、Annex D (informative) Measuring technique selection 36Bibliography 40BS EN 14127:2011EN 14127:2011 (E) 4 Foreword This document (EN 14127:2011) 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 gi

18、ven the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2011, and conflicting national standards shall be withdrawn at the latest by August 2011. Attention is drawn to the possibility that some of the elements of this document may

19、be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 14127:2004, which has been editorially revised, in order to take into account the new edition of EN 1330-4:2010. According to the CEN/CENELEC I

20、nternal 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, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Lu

21、xembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 14127:2011EN 14127:2011 (E) 5 1 Scope This European Standard specifies the principles for ultrasonic thickness measurement of metallic and non-metallic materi

22、als by direct contact, based on measurement of time-of-flight of ultrasonic pulses only. 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

23、of the referenced document (including any amendments) applies. EN 583-2, Non-destructive testing Ultrasonic examination Part 2: Sensitivity and range setting EN 1330-4:2010, Non-destructive testing Terminology Part 4: Terms used in ultrasonic testing 3 Terms and definitions For the purposes of this

24、document, the terms and definitions given in EN 1330-4:2010 apply. 4 Measurement modes The thickness of a part or structure is determined by accurately measuring the time required for a short ultrasonic pulse generated by a transducer to travel through the thickness of the material once, twice or se

25、veral times. The material thickness is calculated by multiplying the known sound velocity of the material with the transit time and dividing by the number of times the pulse transits the material wall. This principle can be accomplished by applying one of the following modes, see Figure 1: a) Mode 1

26、: Measure the transit time from an initial excitation pulse to a first returning echo, minus a zero correction to account for the thickness of the transducer wear surface and the couplant layer (single echo mode). b) Mode 2: Measure the transit time from the end of a delay line to the first backwall

27、 echo (single echo delay line mode). c) Mode 3: Measure the transit time between back-wall echoes (multiple echoes). d) Mode 4: Measure the transit time for a pulse travelling from the transmitter to a receiver in contact with the back-wall (through transmission mode). BS EN 14127:2011EN 14127:2011

28、(E) 6 Mode 1 Mode 2Mode 3 Mode 4 Key A transmit/receive probe D transmission pulse indication A1 transmit probe E1 to E3 back-wall echoesA2 receive probe F interface echoA3 dual element probe G delay pathB test object H received pulseC sound path travel time Figure 1 Measurement modes BS EN 14127:20

29、11EN 14127:2011 (E) 7 5 General requirements 5.1 Instruments Thickness measurement can be achieved by using the following types of instruments: a) dedicated ultrasonic thickness measurement instruments with numerical display showing the measured value; b) dedicated ultrasonic thickness measurement i

30、nstruments with numerical display showing the measured value and A-scan presentation (waveform display); c) instruments designed primarily for detection of discontinuities with A-scan presentation of signals. This type of instrument may also include numerical display of thickness values. See 6.4. 5.

31、2 Probes The following types of probes are used, these are generally longitudinal wave probes: dual element probes; single transducer probes. See 6.3. 5.3 Couplant Acoustic contact between probe (probes) and material has to be provided, normally by application of a fluid or gel. The couplant shall n

32、ot have any adverse effect on the test object, the equipment or represent a health hazard to the operator. For couplant to be used in special measuring conditions see 6.6. The coupling medium should be chosen to suit the surface conditions and the irregularities of the surface to ensure adequate cou

33、pling. 5.4 Reference blocks The measuring system shall be calibrated on one or more samples or reference blocks representative of the object to be measured, i.e. having comparable dimensions, material and structure. The thickness of the blocks or the steps should cover the range of thickness to be m

34、easured. Either the thickness or the sound velocity of the reference blocks shall be known. 5.5 Test objects The object to be measured shall allow for ultrasonic wave propagation. There shall be free access to each individual area to be measured. The surface of the area to be measured shall be free

35、of all dirt, grease, lint, scale, welding flux and spatter, oil or other extraneous matter that could interfere with the examination. If the surface is coated, the coating shall have good adhesion to the material. Otherwise it shall be removed. When measuring through coating its thickness and sound

36、velocity need to be known unless mode 3 is used. BS EN 14127:2011EN 14127:2011 (E) 8 For further details, see Clause 8. 5.6 Qualification of personnel An operator performing ultrasonic thickness measurement according to this document shall have a basic knowledge of the physics of ultrasonics, and a

37、detailed understanding and training related to ultrasonic thickness measurements. In addition, the operator shall have knowledge of the product and material to be measured. It is assumed that ultrasonic thickness testing is performed by qualified and capable personnel. In order to prove this qualifi

38、cation, it is recommended to certify the personnel in accordance with EN 473 or equivalent. Note that for pressure equipment in categories III and IV according to Directive 97/23/EC, Annex I, 3.1.3: the personnel must be approved by a third-party organization recognized by a Member State. 6 Applicat

39、ion of the technique 6.1 Surface conditions and surface preparation Using the pulse-echo method means that the ultrasonic pulse has to pass the contact surface between test object and the probe at least twice: when entering the object and when leaving it. Therefore a clean and even contact area with

40、 at least two times the probes diameter is preferred. Poor contact will result in loss of energy, distortion of signal and sound path. To enable sound propagation all loose parts and non adherent coatings shall be removed by brushing or grinding. Attached layers, like colour coating, plating, enamel

41、s, may stay on the object, but only a few thickness meters are able to exclude these layers from being measured. Very often thickness measurements have to be done on corroded surfaces, e.g. storage tanks and pipelines. To increase measuring accuracy the contact surface should be ground within an are

42、a at least two times the probes diameter. This area should be clean from corrosion products. 6.2 Technique 6.2.1 General The task of ultrasonic thickness measurements can be separated into two application areas: measurement during manufacture; in-service measurements of residual wall thickness. Each

43、 area has its own special conditions which require special measuring techniques. With a knowledge of the material, geometry and thickness to be measured and the required accuracy the most suitable measuring equipment and mode can be selected. Annex D gives further guidance: a) depending on the thick

44、ness and the material, frequencies from 100 kHz with through transmission on highly attenuative materials up to 50 MHz on thin metal sheets shall be used; b) if dual element probes are used then compensation for V-path error is required; c) on curved objects the diameter of the probe contact area sh

45、all be significantly smaller than the diameter of the test object; BS EN 14127:2011EN 14127:2011 (E) 9 d) the accuracy of the thickness measurement depends on how accurate the time-of-flight can be measured, depending on the mode of time-measuring (zero crossing, flank-to-flank, peak-to-peak), depen

46、ding on the mode chosen (with multiple echoes, mode 3, the accuracy is higher than with modes 1 and 2), depending on the frequencies which can be used (higher frequencies provide higher accuracy than lower frequencies because of the more accurate time measurement); e) ultrasonic thickness measuremen

47、t is often required over an area of the component to be measured. Where this is the case consideration should be given to the spacing between each measurement. Such spacing should be even and the use of a grid is recommended. The grid size should be selected to give a balance between the confidence

48、in the results and the work content involved. Measuring the thickness ultrasonically means measuring the time-of-flight and then calculating the thickness assuming a constant sound velocity (see Clause 7). If the velocity is not constant within the path the ultrasonic pulse has travelled the accuracy of the measurement will be severely affected. 6.2.2 Measurement during manufacture 6.2.2.1 Modes 1, 2 and 3 Where the pulse echo mode is used, the flow charts in Figures D.1 and D.2 give guidance on the selection of the best method and equipment. Thick