1、BRITISH STANDARD BS 5721:1979 IEC 537:1976 Specification for Frequency weighting for the measurement ofaircraft noise (D-weighting) UDC 656.7.053.7:534.836.2:534.61.089.6BS5721:1979 This British Standard, having been prepared under the directionof the Electronic Equipment Standards Committee,was pub
2、lished underthe authority ofthe Executive Board and comes intoeffect on 30March1979 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference EEL/24 Draft for comment 78/29227 DC ISBN 0 580 10757 4 Cooperating organizations The Electronic Equipment Standards C
3、ommittee, under whose direction this British Standard was prepared, consists of representatives from the following Government department and scientific and industrial organizations: British Broadcasting Corporation* British Electrical and Allied Manufacturers Association (BEAMA) British Radio Equipm
4、ent Manufacturers Association Cable and Wireless Limited Cable Television Association of Great Britain Electricity Supply Industry in England and Wales Electronic Components Industry Federation Electronic Engineering Association Institution of Electronic and Radio Engineers* Ministry of Defence* Pos
5、t Office* Post Office Engineering Union Scientific Instrument Manufacturers Association The organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: British Association of
6、 Otolaryngologists British Medical Association British Society of Audiology Department of Health and Social Security Department of Industry (National Physical Laboratory) Health and Safety Executive Institute of Physics Institute of Sound and Vibration Research Hearing Aid Industry Association Medic
7、al Research Council Royal Aeronautical Society Royal National Institute for the Deaf Royal Society of Medicine Society of Hearing Aid Audiologists Limited Amendments issued since publication Amd. No. Date of issue CommentsBS5721:1979 BSI 12-1999 i Contents Page Cooperating organizations Inside front
8、 cover National foreword ii 1 Scope 1 2 Object 1 3 Characteristics 1 Table I Co-ordinates of the poles and zeros of the transfer function, in the complex frequency plane 1 Table II Frequency response and tolerances 1 Publications referred to Inside front coverBS5721:1979 ii BSI 12-1999 National fore
9、word This British Standard has been prepared under the direction of the Electronic Equipment Standards Committee and is identical with IEC Publication537 “Frequency weighting for the measurement of aircraft noise (D-weighting)” published by the International Electrotechnical Commission (IEC). IEC537
10、 hasbeen specially prepared for use in conjunction with ISO3891 “Acoustics Procedure for describing aircraft noise heard on the ground”. Terminology and conventions. The text of the International Standard has been approved as suitable for publication, without deviation, as a British Standard. Some t
11、erminology and certain conventions are not identical with those used in British Standards; attention is especially drawn to the following. Where the word “standard” appears, referring to this standard, it should be interpreted as “British Standard”. A British Standard does not purport to include all
12、 the necessary provisions 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 International Standard Corresponding British Standard IEC 179:1973 BS 4197
13、:1967 A precision sound level meter (Technically equivalent) ISO 3891:1978 BS 5727:1979 aAcoustics Procedure for describing aircraft noise heard on the ground (Identical) a In course of preparation. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1
14、 and 2, 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.BS5721:1979 BSI 12-1999 1 1 Scope A special frequency weighting has been found useful f
15、or certain measurements of aircraft noise. This standard has been specially prepared for use in conjunction with ISO standards 1)on aircraft noise measurements. 2 Object This standard defines a weighting characteristic which is designated D for the above-mentioned purpose. Adherence to this standard
16、 will ensure minimum variations in measurement results obtained using equipment of various makes and models. A special equipment that has a D-weighting characteristic as defined in this standard and otherwise complies with IEC Publication179, Precision Sound Level Meters, has been accepted for the m
17、easurement of aircraft noise. 3 Characteristics The D-response is obtained with the combination of poles and zeros in the complex frequency plane given inTable I. The relative frequency response with tolerance corresponding to this pole-zero configuration is given inTable II. The reading of an instr
18、ument that includes D-weighting is to be identical to sound pressurelevel at1kHz. Table I Co-ordinates of the poles and zerosof the transfer function, in the complexfrequency plane Table II Frequency response and tolerances 1) ISO3891, replacing ISO Recommendations R507 (second edition) and R1761. P
19、oles (magnitude is resonant frequency in hertz) Zeros (magnitude is resonantfrequency in hertz) 282.7+j0 519.8+j 876.2 1160.0+j0 519.8j 876.2 1712 +j2628 0+j0 1712 j2628 Frequency (Hz) Relative response (dB) Tolerance (dB) 10 12.5 16 20 25 31.5 40 50 63 80 100 125 160 200 250 315 400 500 630 800 100
20、0 1250 1600 2000 2500 3150 4000 5000 6300 8000 10000 12500 16000 20000 26.6 24.6 22.6 20.6 18.7 16.7 14.7 12.8 10.9 9.0 7.2 5.5 4.0 2.6 1.6 0.8 0.4 0.3 0.5 0.6 0.0 2.0 4.9 7.9 10.4 11.6 11.1 9.6 7.6 5.5 3.4 1.4 0.7 2.7 +3.0, Z +3.0, Z +3.0, Z 3.0 2.0 1.5 1.5 1.5 1.5 1.5 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1
21、.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.5 +1.5, 2.0 +1.5, 3.0 +2.0, 4.0 +3.0, 6.0 +3.0, Z +3.0, Z2 blankBS5721:1979 BSI 12-1999 Publications referred to See national forewordBS 5721:1979 IEC537:1976 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent natio
22、nal body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions BritishStandards are updated by amendment or revision. Users of BritishStandards should make sure that they possess the l
23、atest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this BritishStandard would inform the Secretary of the technical committee responsible, the identity of which
24、 can be found on the inside front cover. Tel:02089969000. Fax:02089967400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards. Buying standards Orders for all BSI, international and foreign standards pub
25、lications should be addressed to Customer Services. Tel:02089969001. Fax:02089967001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as BritishStandards, unless otherwise requested. Information on standards BSI p
26、rovides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Various BSI electronic information services are also available which give details on all its products and services. Contact the Information Centre. T
27、el:02089967111. Fax:02089967048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For details of these and other benefits contact Membership Administration. Tel:02089967002. Fax:02089967001. Copyright Cop
28、yright subsists in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the international standardization bodies. Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any fo
29、rm or by any means electronic, photocopying, recording or otherwise without prior written permission from BSI. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel:02089967070.
