1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 13477-2:2010Non-destructive testing Acoustic emission Equipment characterisationPart 2: Verification of operatingcharacteristicBS EN 13477-2:2010 BRITISH STANDARDNational f
2、orewordThis British Standard is the UK implementation of EN 13477-2:2010.It supersedes BS EN 13477-2:2001 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee WEE/46, Non-destructive testing.A list of organizations represented on this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 beobtaine
3、d on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2010ISBN 978 0 580 61010 3ICS 17.140.01; 19.100Compliance with a British Standard cannot confer immunity fromlegal obligations.T
4、his British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 October 2010.Amendments issued since publicationDate Text affectedBS EN 13477-2:2010EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13477-2 September 2010 ICS 19.100 Supersedes EN 13477-2:
5、2001English Version Non-destructive testing - Acoustic emission - Equipment characterisation - Part 2: Verification of operating characteristicEssais non destructifs, mission acoustique - Caractrisation de lquipement - Partie 2: Vrifications des caractristiques de fonctionnement Zerstrungsfreie Prfu
6、ng - Schallemissionsprfung - Gertecharakterisierung - Teil 2: berprfung der Betriebskenngren This European Standard was approved by CEN on 30 July 2010. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the stat
7、us 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 Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A
8、 version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czec
9、h 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 COMMITTEE FOR STANDARDIZATION COMIT EURO
10、PEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13477-2:2010: EBS EN 13477-2:2010EN 13477-2:2010 (E) 2 Contents Page Fore
11、word 41 Scope 52 Normative references 53 Terms and definitions .54 Required test equipment .54.1 List of required equipment .54.2 Test signal waveforms 64.2.1 Continuous sine wave .64.2.2 Triangular modulated sine wave 64.2.3 Sine-modulated sine wave .74.2.4 Rectangular modulated sine wave .84.2.5 P
12、ulse .94.2.6 Repetitive signals 94.3 Test Body . 104.4 Shielding test plate . 105 Sensor verification 105.1 General . 105.2 Uses . 105.3 Procedure 105.3.1 Preliminary examination 105.3.2 Sensitivity verification 105.3.3 Verification of electrical shielding 115.3.4 Electrical noise verification of a
13、sensor-preamplifier combination 116 Preamplifier verification . 126.1 General . 126.2 Verification of DC-current consumption 126.3 Measurement of preamplifier characteristics 136.3.1 General . 136.3.2 Gain 136.3.3 Bandwidth 136.3.4 Electronic noise 156.3.5 Dynamic range 166.3.6 Pulsing test 167 AE s
14、ignal processor verification . 167.1 Overview 167.2 Bandwidth and filter roll-off verification . 177.3 Detection threshold verification 177.4 AE signal processor noise verification 177.5 Burst signal parameter verification 187.5.1 General . 187.5.2 Peak amplitude 187.5.3 Duration . 207.5.4 Rise time
15、 207.5.5 Ring down count . 207.5.6 Energy 207.6 Parameters for continuous signal . 218 External parameter verification . 219 System acquisition rate verification . 21BS EN 13477-2:2010EN 13477-2:2010 (E) 3 10 t measurement verification . 2211 Documentation 22Annex A (informative) Sensor performance
16、check form 25Annex B (informative) Preamplifier performance check form 27Annex C (informative) AE signal processor - bandwidth Part 2: Verification of operating characteristic. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are boun
17、d to implement this European Standard: 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, Slovenia, Spain, S
18、weden, Switzerland and the United Kingdom. BS EN 13477-2:2010EN 13477-2:2010 (E) 5 1 Scope This part of the standard specifies methods for routine verification of the performance of AE equipment comprising one or more sensing channels. It is intended for use by operators of the equipment under labor
19、atory conditions. Verification of the measurement characteristics is recommended after purchase of equipment, modifications, use under extraordinary conditions, or if one suspects a malfunction. The procedures described in this European Standard do not exclude other qualified methods, e.g. verificat
20、ion in the frequency domain. 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 (including any amendments) applie
21、s. EN 1330-1:1998, Non destructive testing Terminology Part 1: List of general terms EN 1330-2:1998, Non destructive testing Terminology Part 2: Terms common to the non-destructive testing methods EN 1330-9:2009, Non-destructive testing Terminology Part 9: Terms used in acoustic emission testing EN
22、13477-1:2001, Non-destructive testing Acoustic emission Equipment characterisation Part 1: Equipment description IEC 60050 (all parts), International Electrotechnical Vocabulary 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 1330-1:1998, EN 1330-2:19
23、98, EN 1330-9:2009 and IEC 60050 (all parts) and the following apply. 3.1 AE signal processor part of an AE channel for the conversion of the output of the preamplifier to digital signal parameters NOTE The AE signal processor may include additional support functions, e.g. preamplifier power supply,
24、 test pulse control, transient recorder, and more. 3.2 arbitrary function generator (AFG) electronic device for generating a programmable test signal (burst) 3.3 DC calibrator electronic device for generating an adjustable or programmable DC voltage of appropriate accuracy for stimulating an externa
25、l parametric input 4 Required test equipment 4.1 List of required equipment The following minimum test equipment is required: BS EN 13477-2:2010EN 13477-2:2010 (E) 6 a) test body; b) shielding test plate; c) Hsu-Nielsen source, for sensor sensitivity verification; d) sweep function/variable pulse ge
26、nerator (if function not included in f); e) multimeter, e.g. for DC voltage and DC current measurement; f) test signal generator, e.g. AE calibrator or arbitrary function generator (AFG); g) variable attenuator, graduated in decibels, can be part of the test signal generator; h) DC-calibrator, for e
27、xternal parameter stimulation; i) DC-power-supply, for preamplifier supply, with a proper circuit to decouple and terminate the AE signal, if the power is fed-in over the signal wire; j) RMS voltmeter, with known or settable time constant or time window; k) dual channel storage oscilloscope, for pre
28、amplifier verification, peak noise measurement and identification of any artefacts on the AE signal. NOTE Items i) to k) can be substituted by a verified AE signal processor comprising peak amplitude and RMS measurement. The inaccuracy of the test signal generator shall be significantly lower than t
29、he acceptable inaccuracies given in this standard and summarized in Table 3. Less accurate test signal generators can be used, if the inaccuracy of each pattern is measured and considered during verification. The reproducibility of the DC calibrator output shall be significantly lower than the accep
30、table inaccuracy of the external parameter verification. The inaccuracy of the DC calibrator at the used measurement levels shall be obtained and considered during verification (see Clause 8). All electric/electronic test items shall be calibrated to ensure traceability to SI units. 4.2 Test signal
31、waveforms The following types of test signals shall be used to verify the operating characteristics of the AE measurement system: 4.2.1 Continuous sine wave This type of test signal shall be used to verify the frequency response and gain of the preamplifier and the continuous signal level accuracy o
32、f the AE signal processor. 4.2.2 Triangular modulated sine wave This type of wave simulates an AE burst signal, see Figure 1. It is defined by the following characteristics: A = amplitude; R = rise-time; D = duration; f = carrier frequency. BS EN 13477-2:2010EN 13477-2:2010 (E) 7 Key mV amplitude Fi
33、gure 1 Triangular modulated sine wave in time (left) and frequency (right) domain The measured rise time may be shorter than the visible rise time of the test signal because rise time measurement starts at the time of the first threshold crossing. Table 1 shows the dependency of this threshold cross
34、ing delay on the difference between maximum amplitude and threshold setting in an AE channel. 4.2.3 Sine-modulated sine wave A sine-modulated signal (see Figure 2) can be used as an alternative to a triangular modulated sine wave. Due to its smooth begin, peak and end, its spectrum is very pure and
35、the influence of filter overshoot and filter ring down behaviour is reduced. This signal can be used to obtain the frequency response of the bandpass of a preamplifier or AE signal processor by burst peak amplitude measurement. Key mV amplitude Figure 2 Sine-modulated sine wave in time (left) and fr
36、equency domain (right) NOTE The shown signal corresponds to the following function: )/(sin)/2sin( SWpBSpSWNSpSWNUNUP= (1) 0=N to )SWpB(SpSW , in integer steps (2) where N = number of each sample in time order; SpSW = Samples per sine wave (48 in Figure 2); SWpB = Sine waves per burst (41 in Figure 2
37、); UN = Voltage of sample N; BS EN 13477-2:2010EN 13477-2:2010 (E) 8 PU = Peak amplitude (100 mV in Figure 2) of simulated burst. The resulting carrier frequency fc is a function of the sample time interval (ts): ()SpSWtf =sc1 (3) or the time interval (ts) for a certain carrier frequency is ()SpSWft
38、 =cs1 (4) Example in Figure 2: ts= 1/(200 kHz x 48) = 104.167 ns Similar to the triangular modulated sine wave, the rise time measured by an AE signal processor is shorter than the visible rise time of the test signal, because rise time measurement starts at the time of the first threshold crossing.
39、 This so-called “first threshold crossing delay” depends on the difference of maximum amplitude and detection threshold in dB and is listed for the two modulated test signals in Table 1. Table 1 First threshold crossing delay versus amplitude to threshold ratio for a sin2and triangular modulated tes
40、t signal Threshold Sin modulated first threshold crossing delay % of signal rise time Triangular modulated first threshold crossing delay % of signal rise time A 20 dB 19,7 11,0 A 25 dB 15,0 6,0 A 30 dB 12,3 3,5 A 35 dB 8,3 3,0 A 40 dB 7,6 1,0 4.2.4 Rectangular modulated sine wave This type of signa
41、l is defined by the characteristics A, D and f, see 4.2.2 and Figure 3. Key mV amplitude Figure 3 Rectangular modulated sine wave in time (left) and frequency domain (right) BS EN 13477-2:2010EN 13477-2:2010 (E) 9 4.2.5 Pulse This test signal shall be used to check the measurement of t. It is define
42、d by the characteristics A (amplitude) and D (pulse duration). Figure 4 shows the output of an arbitrary function generator where one sample in a cyclic output buffer was set to 0,8 V, all others to zero. The buffer was output at a sample interval of 50 ns. A pulse duration between 50 ns and 500 ns
43、is recommended. The pulse amplitude shall cause a signal amplitude of about 6 dB above the detection threshold. A much higher amplitude may cause additional threshold crossings by ring down cycles as shown in Figure 5. Figure 4 Pulse 4.2.6 Repetitive signals This signal is used to verify the signal
44、processing rate. It is a series of pulses as described in 4.2.5. It is defined by A (amplitude), D (pulse duration) and f (repetition frequency), typically 1 Hz 10 kHz. Figure 5 shows an example with 1/f = 160 s, taken after the band pass filter of an AE signal processor. The maximum reasonable repe
45、tition frequency is limited by the ring down effect of the band pass filter, if a pulse causes multiple threshold crossings. Key mV amplitude Figure 5 A series of transient signals (pulses) 160 s apart behind the band pass BS EN 13477-2:2010EN 13477-2:2010 (E) 10 4.3 Test Body This can take differen
46、t forms, e.g. a metallic block, or a plate, or an acrylic rod. Once chosen, the dimensions, construction material, Hsu-Nielsen source position, sensor mounting position and usage shall be controlled to ensure reproducibility of results. The surface in contact with the sensor shall be flat and smooth
47、. The test body shall be isolated acoustically from the work bench to avoid interference from external noise sources. 4.4 Shielding test plate This is a small flat metallic plate sufficient in size to cover the sensors sensitive area. The plate shall be connected to a sine wave; therefore, it shall
48、be electrically isolated from earth. Once chosen, the dimension of the plate and the thickness of the non-conductive layer, if applicable, shall be controlled. The test plate shall be given an identifier for use in the verification report. See Figure 6 for the setup. 5 Sensor verification 5.1 Genera
49、l The following procedure allows rapid comparison of the sensitivity of sensors. The deterioration of the sensors can result from e.g. mechanical shock, exposure to high temperature, high ionizing radiation or a corrosive environment, water ingress, a damaged connector or cable. 5.2 Uses The specific objectives of the procedure for checking sensors are: warning of degrading
