ASA S12 62-2012 American National Standard Acoustics C Attenuation of sound during propagation outdoors C Part 2 General method of calculation - Nationally Adopted International St.pdf

1、 ANSI/ASA S12.62-2012 / ISO 9613-2:1996 (MOD) (a Modified Nationally Adopted International Standard) AMERICAN NATIONAL STANDARD Acoustics Attenuation of sound during propagation outdoors Part 2: General method of calculation Accredited Standards Committee S12, Noise Standards Secretariat Acoustical

2、Society of America 35 Pinelawn Road, Suite 114E Melville, NY 11747-3177ANSI/ASAS12.62-2012 / ISO9613-2:1996(MOD)The American National Standards Institute, Inc. (ANSI) is the national coordinator of voluntary standards development and the clearinghouse in the U.S.A. for information on national and in

3、ternational standards. The Acoustical Society of America (ASA) is an organization of scientists and engineers formed in 1929 to increase and diffuse the knowledge of acoustics and to promote its practical applications. ANSI/ASA S12.62-2012 / ISO 9613-2:1996 (MOD) (A Modified Nationally Adopted Inter

4、national Standard) AMERICAN NATIONAL STANDARD Acoustics Attenuation of sound during propagation outdoors Part 2: General method of calculation Secretariat: Acoustical Society of America Approved on September 5, 2012 by: American National Standards Institute, Inc. Abstract This modified Nationally Ad

5、opted International Standard specifies an engineering method for calculating the attenuation of sound during propagation outdoors in order to predict the levels of environmental noise at a distance from a variety of sources. The method predicts the equivalent continuous A-weighted sound pressure lev

6、el (as described in parts 1 to 3 of ISO 1996) under meteorological conditions favorable to propagation from sources of known sound emission. AMERICAN NATIONAL STANDARDS ON ACOUSTICS The Acoustical Society of America (ASA) provides the Secretariat for Accredited Standards Committees S1 on Acoustics,

7、S2 on Mechanical Vibration and Shock, S3 on Bioacoustics, S3/SC 1 on Animal Bioacoustics, and S12 on Noise. These committees have wide representation from the technical community (manufacturers, consumers, trade associations, organizations with a general interest, and government representatives). Th

8、e standards are published by the Acoustical Society of America as American National Standards after approval by their respective Standards Committees and the American National Standards Institute (ANSI). These standards are developed and published as a public service to provide standards useful to t

9、he public, industry, and consumers, and to Federal, State, and local governments. Each of the Accredited Standards Committees (operating in accordance with procedures approved by ANSI) is responsible for developing, voting upon, and maintaining or revising its own Standards. The ASA Standards Secret

10、ariat administers Committee organization and activity and provides liaison between the Accredited Standards Committees and ANSI. After the Standards have been produced and adopted by the Accredited Standards Committees, and approved as American National Standards by ANSI, the ASA Standards Secretari

11、at arranges for their publication and distribution. An American National Standard implies a consensus of those substantially concerned with its scope and provisions. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by direct

12、ly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered and that a concerted effort be made towards their resolution. The use of an American National Standard is

13、completely voluntary. Their existence does not in any respect preclude anyone, whether he or she has approved the Standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the Standards. NOTICE: This American National Standard may be r

14、evised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw this Standard. Acoustical Society of America ASA Secretariat 35 Pinelawn Road, Suite 114E Melville, New York 11747-3177 Telephone: 1

15、 (631) 390-0215 Fax: 1 (631) 390-0217 E-mail: asastdsaip.org 2012 by Acoustical Society of America. This standard may not be reproduced in whole or in part in any form for sale, promotion, or any commercial purpose, or any purpose not falling within the provisions of the U.S. Copyright Act of 1976,

16、without prior written permission of the publisher. For permission, address a request to the Standards Secretariat of the Acoustical Society of America. These materials are subject to copyright claims of ISO and/or IEC and ANSI and ASA. No part of this publication may be reproduced in any form, inclu

17、ding an electronic retrieval system, without the prior written permission of the Acoustical Society of America (ASA). All requests pertaining to this standard should be submitted to the Acoustical Society of America (ASA). 2012 Acoustical Society of America All rights reserved iContents 1 Scope . 1

18、2 Normative references . 2 3 Definitions 2 4 Source description . 4 5 Meteorological conditions 4 6 Basic equations 5 7 Calculation of the attenuation terms 6 7.1 Geometrical divergence (Adiv) . 6 7.2 Atmospheric absorption (Aatm) 6 7.3 Ground effect (Agr) 7 7.4 Screening (Abar) . 11 7.5 Reflections

19、 17 8 Meteorological correction (Cmet) . 19 9 Accuracy and limitations of the method . 21 Annex A (informative) Additional types of attenuation (Amisc) 23 A.1 Foliage (Afol) 23 A.2 Industrial sites (Asite) 24 A.3 Housing (Ahous) 24 Bibliography 26 Figures Figure 1 Three distinct regions for determin

20、ation of ground attenuation . 8 Figure 2 Functions a, b, c and d representing the influence of the source-to-receiver distance dpand the source or receiver height h, respectively, on the ground attenuation Agr(computed from equations in table 3) 10 Figure 3 Method for evaluating the mean height hm11

21、 Figure 4 Plan view of two obstacles between the source (S) and the receiver (R) . 12 Figure 5 Different sound propagation paths at a barrier 13 Figure 6 Geometrical quantities for determining the pathlength difference for single diffraction . 14 2012 Acoustical Society of America All rights reserve

22、d iiFigure 6a U.S. MODIFICATION: Plan view showing distances described in Equation 16 and Figure 6, elevation view, for a thin single barrier. In this case, dssand dsrare the projections of the lines on the horizontal plane. . 14 Figure 7 Geometrical quantities for determining the pathlength differe

23、nce for double diffraction . 15 Figure 7a U.S. MODIFICATION: Plan view showing distances described in Equation 17 and Figure 7, elevation view, for a thick barrier. In this case, dssand dsrare the projections of the lines on the horizontal plane. . 15 Figure 7b U.S. MODIFICATION: Plan view showing d

24、istances described in Equation 17 and Figure 7, elevation view, for a multiple barrier. In this case, dssand dsrare the projections of the lines on the horizontal plane. . 16 Figure 8 Specular reflection from an obstacle . 18 Figure 9 Estimation of sound reflection coefficient for a cylinder . 19 Fi

25、gure 10 Meteorological correction Cmet. 20 Figure A.1 Attenuation due to propagation through foliage increases linearly with propagation distance dfthrough the foliage . 23 Figure A.2 The attenuation Asiteincreases linearly with the propagation distance dsthrough the installations at industrial plan

26、ts 24 Tables Table 1 - Symbols and units 3 Table 2 Atmospheric attenuation coefficient for octave bands of noise . 7 Table 3 Expressions to be used for calculating ground attenuation contributions As, Ar, and Amin octave bands 9 Table 4 Estimates of the sound reflection coefficient . 19 Table 5 Esti

27、mated accuracy for broadband noise of LAT(DW) calculated using equations (1) to (10) . 22 Table A.1 Attenuation of an octave band of noise due to propagation distance dfthrough dense foliage. 24 Table A.2 Attenuation coefficient of an octave band of noise during propagation through installations at

28、industrial plants 24 2012 Acoustical Society of America All rights reserved iiiForeword This Foreword is for information only and is not a part of ANSI/ASA S12.62-2012/ISO 9613-2:1996 (MOD) American National Standard Acoustics Attenuation of sound during propagation outdoors Part 2: General method o

29、f calculation. This standard comprises a part of a group of definitions, standards, and specifications for use in noise. It was developed and approved by Accredited Standards Committee S12 Noise, under its approved operating procedures. Those procedures have been accredited by the American National

30、Standards Institute (ANSI). The Scope of Accredited Standards Committee S12 is as follows: Standards, specifications, and terminology in the field of acoustical noise pertaining to methods of measurement, evaluation, and control, including biological safety, tolerance, and comfort, and physical acou

31、stics as related to environmental and occupational noise. This standard is an editorially modified version of ISO 9613-2:1996 Acoustics Attenuation of sound during propagation outdoors Part 2: General method of calculation, which was prepared by ISO/TC 43/ SC 1, Noise. In conformance with ANSI and I

32、SO rules, the words “this American National Standard“ replace the words “this part of ISO 9613“ where they appear in the ISO document, decimal points were substituted in place of the decimal commas used in ISO documents, and American English spelling is used in place of British English spelling. In

33、addition, figures were added to help clarify geometry and some editorial changes were made to improve clarity. All editorial additions and modifications are shown in a bold blue font within a blue box and are identified as U.S. Modifications. Technically, there is no difference between this version

34、and ISO 9613-2:1996. Annexes A and B of ANSI/ASA S12.62-2012 / ISO 9613-2:1996 (MOD) are for information only. At the time this Standard was submitted to Accredited Standards Committee S12, Noise for approval, the membership was as follows: W.J. Murphy, Chair S.J. Lind, Vice-Chair S.B. Blaeser, Secr

35、etary 3M Occupational Health FAX: 631-390-0217; E-mail: asastdsaip.org. AMERICAN NATIONAL STANDARD ANSI/ASA S12.62-2012 / ISO 9613-2:1996 (MOD) 2012 Acoustical Society of America All rights reserved 1AMERICAN NATIONAL STANDARD Acoustics Attenuation of sound during propagation outdoors Part 2: Genera

36、l method of calculation 1 Scope This American National Standard specifies an engineering method for calculating the attenuation of sound during propagation outdoors in order to predict the levels of environmental noise at a distance from a variety of sources. The method predicts the equivalent conti

37、nuous A-weighted sound pressure level (as described in parts 1 to 3 of ISO 1996) under meteorological conditions favorable to propagation from sources of known sound emission. These conditions are for downwind propagation, as specified in 5.4.3.3 of ISO 1996-2:1987 or, equivalently, propagation unde

38、r a well-developed moderate ground-based temperature inversion, such as commonly occurs at night. Inversion conditions over water surfaces are not covered and may result in higher sound pressure levels than predicted from this American National Standard. The method also predicts a long-term average

39、A-weighted sound pressure level as specified in ISO 1996-1 and ISO 1996-2. The long-term average A-weighted sound pressure level encompasses levels for a wide variety of meteorological conditions. The method specified in this American National Standard consists specifically of octave-band algorithms

40、 (with nominal midband frequencies from 63 Hz to 8 kHz) for calculating the attenuation of sound which originates from a point sound source, or an assembly of point sources. The source (or sources) may be moving or stationary. Specific terms are provided in the algorithms for the following physical

41、effects: geometrical divergence; atmospheric absorption; ground effect; reflection from surfaces; screening by obstacles. Additional information concerning propagation through housing, foliage and industrial sites is given in annex A. This method is applicable in practice to a great variety of noise

42、 sources and environments. It is applicable, directly or indirectly, to most situations concerning road or rail traffic, industrial noise sources, construction activities, and many other ground-based noise sources. It does not apply to sound from aircraft in flight, or to blast waves from mining, mi

43、litary or similar operations. To apply the method of this American National Standard, several parameters need to be known with respect to the geometry of the source and of the environment, the ground surface characteristics, and the source strength in terms of octave-band sound power levels for dire

44、ctions relevant to the propagation. NOTE 1 If only A-weighted sound power levels of the sources are known, the attenuation terms for 500 Hz may be used to estimate the resulting attenuation. ANSI/ASA S12.62-2012 / ISO 9613-2:1996 (MOD) 2012 Acoustical Society of America All rights reserved 2The accu

45、racy of the method and the limitations to its use in practice are described in clause 9. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this American National Standard. At the time of publication, the editions indicat

46、ed were valid. All standards are subject to revision, and parties to agreements based on this American National Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid I

47、nternational Standards. ISO 1996-1:1982, Acoustics Description and measurement of environmental noise Part 1: Basic quantities and procedures. ISO 1996-2:1987, Acoustics Description and measurement of environmental noise Part 2: Acquisition of data pertinent to land use. ISO 1996-3:1987, Acoustics D

48、escription and measurement of environmental noise Part 3: Application to noise limits. ISO 9613-1:1993, Acoustics Attenuation of sound during propagation outdoors Part 1: Calculation of the absorption of sound by the atmosphere. IEC 651:1979, Sound level meters, and Amendment 1:1993. U.S. MODIFICATI

49、ON: IEC 651:1979 has been superseded by IEC 61672-1 and IEC 61672-2, and the ISO 1996 series has been revised. 3 Definitions For the purposes of this American National Standard, the definitions given in ISO 1996-1 and the following definitions apply. (See table 1 for symbols and units.) 3.1 equivalent continuous A-weighted sound pressure level, LAT: Sound pressure level, in decibels, defined by equation (1): TATLTptp22A0010 lg 1/ ( )d dB(1) where pA(t) is the