1、BRITISH STANDARD BS 6086:1981 ISO 5128:1980 Method of Measurement of noise inside motor vehicles ISO title: Acoustics Measurement of noise inside motor vehicles UDC 614.872.4:534.61:629.11BS6086:1981 This British Standard, having been prepared under the directionof the Environment andPollution Stand
2、ards Committee, was published underthe authority of the Executive Board and comesintoeffect on 31December1981 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference EPC/1 Draft for comment 76/52791 DC ISBN 0 580 11886 X Cooperating organizations The Environ
3、ment and Pollution Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: Association of County Councils Department of Industry (Warren Spring British Gas Corporation Laboratory) British Industrial Measuring and Control Electric
4、ity Supply Industry in England and Apparatus Manufacturers Association Wales British Railways Board Engineering Equipment Users Association* British Steel Industry Greater London Council Chemical Industries Association Health and Safety Executive* Chemical Society Institute of Petroleum Committee fo
5、r Environmental Conservation Medical Research Council* Confederation of British Industry Ministry of Agriculture, Fisheries and Food* Consumer Standards Advisory Committee National Coal Board of BSI National Consumers Council Council of Engineering Institutions National Water Council Department of E
6、nergy (Energy Technology) Scottish Office Department of the Environment (Water Society of Chemical Industry Engineering Division including Water Trades Union Congress DataUnit) The organizations marked with an asterisk in the above list, together with the following, were directly represented on the
7、Technical Committee entrusted with the preparation of this British Standard: Agricultural Engineers Association Institute of Occupational Hygienists Association of Consulting Engineers Institute of Physics British Broadcasting Corporation Institute of Sound and Vibration Research British Internal Co
8、mbustion Engine Research Institution of Electronic and Radio Engineers Institute Limited Institution of Mechanical Engineers British Kinematograph, Sound and Television Institution of Municipal Engineers Society London Transport Executive British Occupational Hygiene Society Motor Industry Research
9、Association Department of Industry (National Physical Post Office Laboratory) Railway Industry Association of Great Britain Department of Transport Royal Automobile Club Electronic Components Industry Federation Royal Institute of British Architects Home Office Society of Motor Manufacturers and Tra
10、ders Institute of Acoustics Limited Incorporated Association of Architects and Transmission and Distribution Association Surveyors (BEAMA) Amendments issued since publication Amd. No. Date of issue CommentsBS6086:1981 BSI 09-1999 i Contents Page Cooperating organizations Inside front cover National
11、foreword ii 1 Scope and field of application 1 2 References 1 3 Nature of tests 1 4 Measured quantities 1 5 Measuring equipment 1 6 Acoustical environment, weather conditions, background noise 2 7 Test road conditions 2 8 Vehicle conditions 2 9 Microphone positions 4 10 Test procedure 5 11 Test repo
12、rt 6 Figure Microphone position with respect to a seat 5 Publications referred to Inside back coverBS6086:1981 ii BSI 09-1999 National foreword This British Standard has been prepared under the direction of the Environment and Pollution Standards Committee and is identical with ISO5128:1980“Acoustic
13、s Measurement of noise inside motor vehicles”, prepared by Subcommittee1, Noise, of ISO Technical Committee43, Acoustics, of the International Organization for Standardization (ISO). Terminology and conventions. The text of the International Standard has been approved as suitable for publication as
14、a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is especially drawn to the following. The comma has been used throughout as a decimal marker. In British Standards it is current practice to use a full poi
15、nt on the baseline as the decimal marker. Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. The Technical Committee has reviewed the provisions of ISO1176:1974, ISO1999:1975, ISO2204:1979, and IEC Publication225:1966 and has de
16、cided that they are acceptable for use in conjunction with this standard. Related British Standards for ISO1999:1975 and IEC Publication225:1966 are BS5330:1976 “Method of test for estimating the risk of hearing handicap due to noise exposure” and BS2475:1964 “Octave and one third octave band-pass f
17、ilters” respectively. ISO 5131, referred to in clause1 for information purposes only, is in course of preparation. NOTETextual errors. When adopting the text of the International Standard, the errors listed below were noticed and acknowledged by ISO/TC43/SC1. In paragraph2 of3.2, “type test” should
18、be read as “verification test”, and in4.2, “type and monitoring tests” should be read as “verification and monitoring tests”. A printing error in8.4.2 has been corrected. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are respons
19、ible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International Standard Corresponding British Standard IEC Publication 651:1979 BS 5969:1981 Specification for sound level meters (Identical) Summary of p
20、ages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS
21、6086:1981 BSI 09-1999 1 1 Scope and field of application This International Standard is the first stage in the development of a test intended to provide a useful definition of interior noise for engineering and contractual purposes. It specifies the conditions for obtaining reproducible and comparab
22、le measurements of the levels of the noise and the noise spectra inside all kinds of motor vehicles intended for road use, including those where the driver and/or passengers occupy an open cabin or even only a well-defined area, but excluding agricultural tractors and field machinery covered by ISO5
23、131. The results may be used, for example: to decide whether or not the noise inside the vehicle is in accordance with noise specifications; to estimate hearing damage risk in conjunction with noise exposure data (seeISO1999); to rate the degree of speech interference; to orient a programme of more
24、elaborate measurements for the purposes of studying noise reduction procedures. The specified procedure is intended neither for the measurement of pressure oscillations at very low frequencies, nor for the assessment of the noise exposure for comfort and security such as fatigue and vigilance. The p
25、resent state of the art does not yet allow a good correlation between measured data and comfort and security. NOTE 1The test procedures described in this International Standard are engineering methods as defined in ISO2204. NOTE 2Measurements may be made on sources emitting noise of an impulsive cha
26、racter with an impulse sound level meter. NOTE 3When repeating a measurement following this International Standard with other vehicles of the same type or on other measuring sites or with other measuring instruments which comply with instruments of type1 of IEC Publication651, differences of the ord
27、er 3dB may be observed in the test results of the A-weighted sound pressure level measurements. 2 References ISO 1176, Road vehicles Weights Vocabulary. ISO 1999, Acoustics Assessment of occupational noise exposure for hearing conservation purposes. ISO 2204, Acoustics Guide to International Standar
28、ds on the measurement of airborne acoustical noise and evaluation of its effects on human beings. ISO 5131, Acoustics Measurement of noise at the operators workplace on agricultural tractors and field machinery Survey method. IEC Publication225, Octave, half-octave and third-octave band filters inte
29、nded for the analysis of sounds and vibrations. IEC Publication 651, Sound level meters. 3 Nature of tests 3.1 Verification tests: Measurements performed to prove that the vehicle delivered by the manufacturer is in accordance with noise specifications. The conditions prescribed for each test shall
30、be complied with as closely as possible, but if unavoidable variations have to be made, these shall be stated in the test report. 3.2 Monitoring tests: Measurements performed in order to check that the noise of the vehicles is still within prescribed limits, and that noticeable changes have not occu
31、rred since delivery, or between individual units of a consignment of vehicles. For monitoring tests, slight deviations from the type test conditions may be tolerated; for example, the number of microphone positions and driving conditions may be reduced. Any variations shall be described in the test
32、report. 4 Measured quantities 4.1 All readings of the sound level meter shall be taken with the dynamic characteristic “fast”. 4.2 The values to be measured at all microphone positions during type and monitoring tests are A-weighted sound pressure levels, L pA , expressed in decibels (dB). 4.3 For s
33、pectral analysis at selected microphone positions during additional special tests, the values to be measured shall be octave band or1/3-octave band sound pressure levels in dB covering at least the frequency range from45 to11200Hz. Measurement of1/3-octave band sound pressure levels is preferred. NO
34、TEIf strong, low frequency components are to be considered the spectral analysis should be extended appropriately below45Hz. 5 Measuring equipment 5.1 The sound level meter shall be of the precision class according to IEC Publication651 (type1). NOTE 1The directivity of the microphone may influence
35、the measurements; therefore, preferably omnidirectional microphones should be used. The type of microphone should be stated in the test report. NOTE 2A suitable wind shield may be used to reduce the influence of wind on the measurements in open vehicles. Wind shields recommended by the sound level m
36、eter manufacturer will generally be suitable. 5.2 If additional measuring equipment, including for example a tape recorder and/or level recorder, is used, its overall electro-acoustic performance shall conform to the relevant clauses of IEC Publication651 concerning type1 instruments.BS6086:1981 2 B
37、SI 09-1999 NOTEIf a tape recorder is used as part of the measuring equipment, it may be necessary to include suitable additional pre-emphasis and de-emphasis networks for recording and reproduction to provide an adequate signal-to-noise ratio over the whole frequency range of interest. 5.3 For the m
38、easurement of noise spectra, the filters shall meet the requirements of IEC Publication225. 5.4 The overall acoustic performance of the measuring equipment shall be checked according to the instructions of the manufacturer, preferably with a standard sound source (for example pistonphone), at the be
39、ginning and at the end of each series of measurements. At time intervals no longer than2years, the sound level meter shall be calibrated for compliance with instruments of type1 of IEC Publication651. NOTEIt is essential that care should be taken that spurious signals are not induced on the micropho
40、ne output by vibration, electromagnetic pick-up or other extraneous influences. It is practical to check for all such signals by capping the microphone to ensure that all non-acoustically generated signals which may be present are at least10dB below the acoustic signal obtained with the uncapped mic
41、rophone under the same measuring conditions. This cap should be suitably heavy and rigid and should provided a good seal around the microphone. 5.5 It is recommended, especially for the acceleration tests, that either a twin-track tape recorder is used to record noise and vehicle speed simultaneousl
42、y or an XY plotter is used to plot noise versus speed directly in the vehicle. 5.6 The measuring equipment shall cover at least the frequency range45 to11200Hz (seenotein4.3). 5.7 Vehicle and engine speed shall be measured with an accuracy of at least3%. 6 Acoustical environment, weather conditions,
43、 background noise 6.1 The test site shall be such that the sound radiated by the vehicle to the outside contributes to the inside noise only by reflections from the road surface and not by reflections from buildings, walls or similar large objects outside the vehicle. During the period of measuremen
44、t, the distance of the vehicle from large objects shall be greater than20m. 6.2 The ambient air temperature in which the vehicle is operating shall be in the range5 to+35 C. The wind speed along the test track measured at a height of approximately1,2m shall not exceed5m/s. The other meteorological c
45、onditions shall be such that they do not influence the measurements. The speed of the wind and the direction of the wind relative to the test track shall be stated in the test report. 6.3 For all measurements of A-weighted sound pressure levels, the lower limit of the dynamic range set by the backgr
46、ound noise and by the inherent noise level of the measuring equipment shall be at least10dB below the A-weighted sound pressure levels of the vehicle noise. In the case of frequency analysis corrections, K shall be applied as calculated from the formula K=10lg(110 0,1%L )dB, if%L 10dB where %L, in d
47、ecibels, is the difference between the frequency band sound pressure levels of the noise inside the vehicle, and the inherent noise of the measuring equipment plus the background noise. No results shall be reported with K(3)dB which corresponds to%L3dB. 7 Test road conditions Interior sound pressure
48、 levels of motor vehicles are greatly influenced in general by the macrotexture of surface roughness of the road, with smooth road surfaces producing consistent interior levels. Accordingly the test road shall be hard and as smooth and level as possible, without gaps or ripples or similar macrotextu
49、re of surface roughness which might contribute to the interior sound pressure levels of the motor vehicle. The surface shall be dry and free from snow, dirt, stones, leaves, etc. 8 Vehicle conditions 8.1 Engine and tyre conditions During the test, all operating conditions of the engine shall correspond to the specifications given by the manufacturer, for example fuel, lubricating oil, timing of ignition or fuel injection pump. The engine shall be stabilized at its normal operating temperature immediately before commencing the test, for example by
