1、CENELEC EN*bL2b5 95 m 3404583 OLbL33L 247 m BRITISH STANDARD Electroacoustics Instruments for measurement of aircraft noise - Performance requirements for systems to measure one-third-octave band sound pressure levels in noise certification of transport-category aircraft The European Standard EN 612
2、65 : 1995 has the status of a British Standard BS EN 61265 : 1995 IEC 1265 : 1995 CENELEC EN*b12b5 95 3404583 OLbL332 183 BS EN 61265 : 1995 under the authority of the Standards Board and comes into effect on 15 October 1995 O BSI 1995 Amd. No. The following BSI references relate to the work on this
3、 standard: Committee reference EPL29 Draft for comment 93208508 DC ISBN O 580 24583 7 Committees responsible for this British Standard Date Rxt affected The preparation of this British Standard was entrusted to Technical Committee EPL/29, Electroacoustics, upon which the following bodies were repres
4、ented: British Association of Otolaryngologists British Hearing Aid Industry Association British Medical Association British Society of Audiology British Telecommunications plc Confederation of British Industry Department of Health Department of Trade and Industry (National Physical Laboratory) Heal
5、th and Safety Executive Institute of Acoustics Institute of Sound and Vibration Research Institute of Electrical Engineers Medical Research Council Ministry of Defence Royal Aeronautical Society Royal National Institute for Deaf people Society of Environmental Engineers University of Exeter BS EN 61
6、265 : 1995 Contents Pwze Committees responsible Inside front cover National foreword ii Foreword 2 %xt of EN 61265 2 CENELEC EN*bL265 95 3404583 OLbL33q T5b BS EN 61265 : 1995 National foreword This British Standard has been prepared by Bchnical Committee EPL/29 and is the English language version o
7、f EN 61265 : 1995, Electroacoustics - Instrumnts for measurement of aircraft mise - Peomzance requirements for systerns to meare one-third-octave band sound pressure levels in noise certqication of transport-category aircraft, published by the European Committee for Electrotechnical Standardization
8、(CENELEC). It is identical with IEC 1265 : 1995, and supersedes BS 5647 : 1979, Specification for electro-acoustical masuring equipment for aircraft mise certqication, which is withdrawn. Cross-references IEC 50 (801) : 1994 Publication referred to EN 60801-2 : 1993 (IEC 801-2 : 1991) HD 481.3 S1 :
9、1987 (IEC 801-3 : 1984) HD 556 S1 : 1991 (IEC 942 : 1988) Corresponding British Standard BS 4727 Glossary of electrotechnical, powei; telecommunication, electronics, lighting and colour terms Part 3 Terms particular to telecommunications and electronics Group 08 : 1995 Acoustics and electroacoustics
10、 BS EN 60801 Electrmnetic compatibility for industrial-process measurement and control equipment Part 2 : 1993 Electrostatic discharge requirements BS 6667 Electromagnetic Compatibility for industrial-process measurement and control equipment Part 3 : 1985 Method of evaluating susceptibility to radi
11、ated electromagnetic energy BS 7189 : 1989 Spehfication for sound calibrators NOTE. IEC 1094-3; IEC 1094-4 and IEC 1260 to which normative reference is made in the text have each been circulated as Draft International Standards with parallel CENELEC vote and are expected to be published in the near
12、future as IEC Standards with corresponding EN and BS EN Publications. Compliance with a British Standard does not of itself confer immunity from legal obligations. CENELEC ENxbLb5 95 m 3404583 OLbL335 992 m EUROPEAN STANDARD NORMEEUROPENNE EUROPISCHE NORM EN 61265 April 1995 ICs 17.140.50 49.020 Des
13、criptors: Electroacoustics, acoustic measuring instruments, acoustic measurements, noise sound, aircraft, sound pressure, level quantity, certification, characteristics, specifications English version Electracoustics Instruments for measurement of aircraft noise Performance requirements for systems
14、to measure one-third-octave band sound pressure levels in noise certification of transport-category aeroplanes (IEC 1265 : 1995) Electroacoustique Instruments pour la mesure du bruit des aronefs Prescriptions relatives aux systmes de mesure des niveaux de pression acoustique par tiers doctave, pour
15、la certification acoustique des avions de transport (CE1 1265 : 1995) Elektroakustik Gerte zur Messung von Flugzeuggeruschen Anforderungen an die Eigenschaften von Systemen zur Messung von Schalldruckpegeln in Terzbndern bei der Zertifizierung von Flugzeugen der Transport-Kategorie (IEC 1265 : 1995)
16、 This European Standard was approved by CENELEC on 1905-03-06. CENELEC members are bound to comply with the CENXENELEC Internal 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
17、references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC 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 CENE
18、LEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway
19、, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1060 Brussels O 1995 Copyright reserv
20、ed to CENELEC members Ref. No. EN 61265 : 1995 E CENELEC EN*bL2b5 95 3404583 OLb133b 829 Page 2 EN 61265 : 1995 Foreword The text of document 29(C0)216, future edition 1 of IEC 1265, prepared by IEC TC 29, Electroacoustics, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC a
21、s EN 61265 on 1995-03-06. The following dates were fixed: - latest date by which the EN has to be implemented at national level by publication of an identical national standard or by latest date by which the national standards conflicting with the EN have to be withdrawn. endorsement (dop) 1996-04-0
22、1 - (dow) 1996-04-01 Annexes designated normative are part of the body of the standard. Annexes designated informative are given for information only. In this standard, annex ZA is normative and annexes A and B are informative. Annex ZA has been added by CENELEC. Introduction This International Stan
23、dard provides requirements for the electroacoustical performance of instruments (that may be components of a complete system) for measurement of the sound produced by aeroplanes in fight or by an aeroplane engine installed on an outdoor test stand. Methods are also indicated by which the performance
24、 of such instruments may be tested periodically. Measurement and data-analysis procedures for aircraft noise certification are described in Volume 1 of Annex 16 to the Convention on International Civil Aviation, with further guidance and descriptions of acceptable equivalent procedures given in the
25、Environmental Bchnical Manual prepared by the ICA0 Committee on Aviation Environmental Protection (CAEP), (see annex A). The procedures include measurement and analysis of the sound from aircraft in flight, and, in some circumstances, of the sound from static engines under test, under given operatin
26、g and atmospheric conditions. Contents Foreword Introduction Clause 1 Scope and object 2 Normative references 3 Definitions 4 Requirements Annexes A (informative) Bibliography B (informative) Methods of testing the electroacoustical performance of a measurement system ZA (normative) Normative refere
27、nces to international publications with their corresponding European publications pw!e 2 2 11 12 14 ELECTROACOUSTICS - INSTRUMENTS FOR MEASUREMENT OF AIRCRAFT NOISE - ONE-THIRD-OCTAVE-BAND SOUND PRESSURE LEVELS IN NOISE CERTIFICATION OF TRANSPORT-CATEGORY AEROPLANES PERFORMANCE REQUIREMENTS FOR SYST
28、EMS TO MEASURE 1 Scopeandobject This International Standard specifies requirements for the electroacoustical performance of systems of instruments used to measure sound for the purposes of aeroplane noise certification, and recommends methods by which tests may be made periodically to verify that th
29、e performance continues to comply with the requirements given within stated tolerances. In general, a sound measurement system for this purpose comprises a combination of instruments extending from a microphone through data recording and processing devices to a suitable output. Particular measuremen
30、t systems, differing in their composition, perform the necessary functions in different ways and operate on either analogue or digital principles. The purpose of this Intemational Standard is to ensure that different measurement systems have the same electroacoustical characteristics within the stat
31、ed tolerances under specified reference environmental conditions. This standard does not provide recommendations for installation of microphones or microphone windscreens, nor requirements for measurement and analysis procedures used in aeroplane noise certification, but gives only the performance s
32、pecifications for the measurement systems used to provide one-third-octave-band sound pressure levels averaged over a period of time. Certain of the requirements apply to the complete measurement system, including any means of recording a time waveform of the sound pressure signal to be measured pri
33、or to analysis. Other requirements apply specifically to the microphone which generates an electrical signal in response to the sound pressure received. Still further requirements apply only to the instruments used to operate on that signal in order to provide an output in the form of one-third-octa
34、ve-band sound pressure levels. The requirements of this International Standard apply to the instruments used to measure the sound produced by jet- or propellerdriven transport-category aeroplanes of maximum certificated takeoff mass over 9 O00 kg, or their propulsion systems when installed on a suit
35、able outdoor engine test stand. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All normative documents are subject
36、to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. IEC 50(801)
37、: 1994, international Electrotechnicai Vocabulary (EV) - Chapter 807: Acoustics and electroacoustics CENELEC EN*h1265 95 m 3404583 OLbL338 bT1 m Page 4 EN 61265 : 1995 IEC 801 -2: 1 991, Electromagnetic compatibility for industrial-process measurement and control equipment - Part 2: Electrostatic di
38、scharge requirements IEC 801 -3: 1 984, Electromagnetic compatibility for industrial-process measurement and control equipment - Part 3: Radiated electromagnetic field requirements IEC 942: 1988, Sound calibrators IEC 1094-3: 199. Measurement microphones - Part 3: Primary method for free-field calib
39、mtion of laboratory standard microphones by the reciprocrty technique (in preparation) ) IEC 1094-4: 199x, Measurement microphones - Part 4: Specifications for working standard microphones (in preparation) 2) IEC 1260: 199x, Electroacoustics - Octave-band and fractional-octave-band filters (in prepa
40、ration) 3 Definitions For the purposes of this international Standard, the following definitions apply. Definitions are consistent with corresponding definitions in IEC 50(801). 3.1 measurement system: Combination of instruments used for the measurement of sound pressure levels, including a sound ca
41、librator, microphone system, signal recording and conditioning devices, and a one-third-octave-band spectrum analysis system. NOTE - Practical installations may indude a number of microphone systems. the wtpvts from which are recorded shnubneoudybya muiti-dmnel recordingdevice.he signai recording an
42、d conditioning devlcesandloriiw spectrum andysis system may have separate channels in parailei. again with facilities for selection, either of the input or of the ougwt For the purpose of this standard, each combination of a single microphone system and a single data-recording and data-analysis chan
43、nel within the other insirumens comprises a separate, complete measurement system, and the requirements apply accordingly. 3.2 microphone system: Components of the measurement system which produce an electrical output signal in response to a sound pressure input signal, and which generally include a
44、 microphone, a preamplifier, extension cables, and other devices as necessary. 3.3 sound-incidence angle: Angle expressed in degrees between the principal axis of the microphone, as defined in IEC 1094-3 and IEC 1094-4, and a line from the sound source to the centre of the diaphragm of the microphon
45、e. NOTE -When the sound inddence angle is O“, the sound is said to be received at the microphone at homial incidence; when the sound inddence angle is 90, the sound Is said to be received at grazlng inddence. 3.4 reference direction: Direction of sound incidence specified by the manufacturer of the
46、microphone, relative to a sound incidence angle of zero degrees, in which the free-field sensitivity level of the microphone system is within specified tolerances. 3.5 free-field sensitivity of a microphone system: For a sinusoidal plane progressive sound wave of specified frequency, at a specified
47、sound-incidence angle, quotient expressed in volts per pascal of the root-mean-square voltage at the output of a microphone system by the root-mean-square sound pressure that would exist at the position of the microphone in the absence of the microphone. 1) 2) 3) Document circulated as a Drafl Inter
48、national Standard under reference 29/294/DIS. Document circulated as a Drafl International Standard under reference 29/295/DIS. Document circulated as a Drafl international Standard under reference 29/292/DIS. CENELEC EN*b1265 95 H 3404583 O363339 538 Page 5 EN 61265 : 1995 3.6 free-field sensitivii
49、 level of a microphone system: In decibels, twenty times the logarithm to the base ten of the ratio of the free-field sensitivity to the reference sensitivity of one volt per pascal. NOTE -The sensitiv level may be determined by subtracting lhe sound pressure level (expressed in dB re 20 pPa) dthesoud incident ai Ihe miaophocie from the voltage level (expressed in dB re 1 V) at the output of the miaophone system, and adding 9398 dB to the result. 3.7 time-average band sound pressure level: In decibels, ten times the logarithm to the base ten of the
