1、BRITISH STANDARD BS EN 61265:1995 IEC1265:1995 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 EN61265:1995 has the s
2、tatus of a BritishStandardBSEN61265:1995 This BritishStandard, having been prepared under the directionof the Electrotechnical Sector Board, was published underthe authority oftheStandards Board and comes into effect on 15October1995 BSI01-2000 The following BSI references relate to the work on this
3、 standard: Committee reference EPL/29 Draft for comment93/208508 DC ISBN 0 580 24583 7 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted to Technical Committee EPL/29, Electroacoustics, upon which the following bodies were represented: British Asso
4、ciation 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) Health and Safety Execu
5、tive 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 Amendments issued since pub
6、lication Amd. No. Date CommentsBSEN61265:1995 BSI 01-2000 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN 61265 3 List of references Inside back coverBSEN61265:1995 ii BSI 01-2000 National foreword This BritishStandard has been prepared by Technic
7、al Committee EPL/29 and is the English language version of EN61265:1995, 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, published by the
8、European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC1265:1995, and supersedes BS5647:1979, Specification for electro-acoustical measuring equipment for aircraft noise certification, which is withdrawn. NOTEIEC1094-3; IEC1094-4 and IEC1260 to which normative ref
9、erence 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 future as IEC Standards with corresponding EN and BS EN Publications. A British Standard does not purport to include all the necessary provisi
10、ons of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references Publication referred to Corresponding BritishStandard IEC50(801):1994 BS4727 Glossary of electro
11、technical, power, telecommunication, electronics, lighting and colour terms Part3 Terms particular to telecommunications and electronics Group08:1995 Acoustics and electroacoustics EN 60801-2:1993 (IEC 801-2:1991) BS EN60801 Electromagnetic compatibility for industrial-process measurement and contro
12、l equipment Part2:1993 Electrostatic discharge requirements HD481.3 S1:1987 (IEC801-3:1984) BS6667 Electromagnetic compatibility for industrial-process measurement and control equipment Part3:1985 Method of evaluating susceptibility to radiated electromagnetic energy HD556 S1:1991 (IEC942:1988) BS71
13、89:1989 Specification for sound calibrators Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to12, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated.
14、 This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 61265 April1995 ICS 17.140.5049.020 Descriptors: Electroacoustics, acoustic measuring instruments, acoustic measurements, noise sound, aircraft, sound pressure, level quantit
15、y, certification, characteristics, specifications English version Electracoustics 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 aeroplanes (IEC1265:1995) Electroac
16、oustique Instruments pour la mesure du bruit des aronefs Prescriptions relatives aux systmes de mesure des niveaux de pression acoustique par tiers doctave, pour la certification acoustique des avions de transport (CEI1265:1995) Elektroakustik Gerte zur Messung von Flugzeuggeruschen Anforderungen an
17、 die Eigenschaften von Systemen zur Messung von Schalldruckpegeln in Terzbndern bei der Zertifizierung von Flugzeugen der Transport-Kategorie (IEC1265:1995) This European Standard was approved by CENELEC on 1905-03-06. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations whi
18、ch 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 Central Secretariat or to any CENELEC member. This European
19、 Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the
20、national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Norm
21、alisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1995 Copyright reserved to CENELEC members Ref.No.EN61265:1995EEN61265:1995 BSI 01-2000 2 Foreword The text of document29(CO)216, future edition1 of IEC1265, prepared
22、by IEC TC29, Electroacoustics, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN61265 on1995-03-06. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. Annexes designated “informative” are given for information only. In
23、this standard, Annex ZA is normative and Annex A and Annex B are informative. Annex ZA has been added by CENELEC. Contents Page Foreword 2 Introduction 3 1 Scope and object 3 2 Normative references 3 3 Definitions 4 4 Requirements 5 Annex A (informative) Bibliography 9 Annex B (informative) Methods
24、of testing theelectroacoustical performance of a measurement system 9 Annex ZA (normative) Normative references tointernational publications with their corresponding European publications 11 Figure 1 Illustration of sound incidence anglesfrom the principal axis of the microphone 6 Table 1 Maximum di
25、fference between the free-field sensitivity level of a microphone system at normal incidence and the free-field sensitivity level at specified soundincidence angles 6 latest date by which the ENhas to be implemented at national level by publication of an identical national standard or by endorsement
26、 (dop) 1996-04-01 latest date by which the national standards conflicting with the EN haveto be withdrawn. (dow) 1996-04-01EN61265:1995 BSI 01-2000 3 Introduction This International Standard provides requirements for the electroacoustical performance of instruments (that may be components of a compl
27、ete system) for measurement of the sound produced by aeroplanes in flight or by an aeroplane engine installed on an outdoor test stand. Methods are also indicated by which the performance of such instruments may be tested periodically. Measurement and data-analysis procedures for aircraft noise cert
28、ification are described in Volume1 of Annex16 to the Convention on International Civil Aviation, with further guidance and descriptions of acceptable “equivalent procedures” given in the Environmental Technical Manual prepared by the ICAO Committee on Aviation Environmental Protection (CAEP), (seeAn
29、nex 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 operating and atmospheric conditions. 1 Scope and object This International Standard specifies requirements for the elect
30、roacoustical 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 the performance continues to comply with the requirements given within stated tolerances. In gener
31、al, 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 measurement systems, differing in their composition, perform the necessary functions in different ways and
32、 operate on either analogue or digital principles. The purpose of this International Standard is to ensure that different measurement systems have the same electroacoustical characteristics within the stated tolerances under specified reference environmental conditions. This standard does not provid
33、e 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 specifications for themeasurement systems used to provide one-third-octave-band sound pressure l
34、evels 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 prior to analysis. Other requirements apply specifically to the microphone which generates an elect
35、rical 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-octave-band sound pressure levels. The requirements of this International Standard apply to the inst
36、ruments used to measure the sound produced by jet- or propeller-driven transport-category aeroplanes of maximum certificated takeoff mass over9000kg, or their propulsion systems when installed on a suitable outdoor engine test stand. 2 Normative references The following normative documents contain p
37、rovisions 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 to revision, and parties to agreements based on this International Standard are encouraged to inve
38、stigate the possibility of applying the most recent editions of the normative documents indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. IEC50(801):1994, International Electrotechnical Vocabulary (IEV) Chapter801: Acoustics and electroacoustics.
39、IEC801-2:1991, Electromagnetic compatibility for industrial-process measurement and control equipment Part2: Electrostatic discharge requirements. IEC801-3:1984, Electromagnetic compatibility for industrial-process measurement and control equipment Part3: Radiated electromagnetic field requirements.
40、 IEC942:1988, Sound calibrators. IEC1094-3:199x, Measurement microphones Part3: Primary method for free-field calibration of laboratory standard microphones by the reciprocity technique (in preparation) 1) . IEC1094-4:199x, Measurement microphones Part4: Specifications for working standard microphon
41、es (in preparation) 2) . 1) Document circulated as a Draft International Standard under reference29/294/DIS. 2) Document circulated as a Draft International Standard under reference29/295/DIS.EN61265:1995 4 BSI 01-2000 IEC1260:199x, Electroacoustics Octave-band and fractional-octave-band filters (in
42、 preparation) 3) . 3 Definitions For the purposes of this International Standard, the following definitions apply. Definitions are consistent with corresponding definitions in IEC50(801). 3.1 measurement system combination of instruments used for the measurement of sound pressure levels, including a
43、 sound calibrator, microphone system, signal recording and conditioning devices, and a one-third-octave-band spectrum analysis system NOTEPractical installations may include a number of microphone systems, the outputs from which are recorded simultaneously by a multi-channel recording device. The si
44、gnal recording and conditioning devices and/or the spectrum analysis system may have separate channels in parallel, again with facilities for selection, either of the input or of the output. For the purpose of this standard, each combination of a single microphone system and a single data-recording
45、and data-analysis channel within the other instruments 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 whi
46、ch generally include a 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 IEC1094-3 and IEC1094-4, and a line from the sound source to the centre of the diaphrag
47、m of the microphone NOTEWhen the sound incidence angle is0 , the sound is said to be received at the microphone at “normal incidence”; when the sound incidence angle is90 , the sound is said to be received at “grazing incidence”. 3.4 reference direction direction of sound incidence specified by the
48、manufacturer of the 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 frequenc
49、y, at a specified 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 3.6 free-field sensitivity 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 NOTEThe free-field sensitivity level may be determined by subtrac
