1、 ANSI/ASA S12.55-2012 / ISO 3745:2012 (a revision of ANSI S12.55-2006 / ISO 3745:2003) AMERICAN NATIONAL STANDARD Acoustics Determination of sound power levels and sound energy levels of noise sources using sound pressure Precision methods for anechoic rooms and hemi-anechoic rooms (a Nationally Ado
2、pted International Standard) Accredited Standards Committee S12, Noise Standards Secretariat Acoustical Society of America 35 Pinelawn Road, Suite 114 E Melville, NY 11747-3177ANSI/ASAS12.55-2012/ ISO 3745:2012The American National Standards Institute, Inc. (ANSI) is the national coordinator of volu
3、ntary standards development and the clearinghouse in the U.S.A. for information on national and international 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 practic
4、al applications. ANSI/ASA S12.55-2012 / ISO 3745:2012 (Revision of ANSI S12.55-2006 / ISO 3745:2003) AMERICAN NATIONAL STANDARD Acoustics Determination of sound power levels and sound energy levels of noise sources using sound pressure Precision methods for anechoic rooms and hemi-anechoic rooms (a
5、nationally adopted international standard) Secretariat: Acoustical Society of America Approved on August 23, 2012 by: American National Standards Institute, Inc. Abstract This American National Standard specifies methods for measuring the sound pressure levels on a measurement surface enveloping a n
6、oise source (machinery or equipment) in an anechoic room or a hemi-anechoic room. The sound power level (or, in the case of impulsive or transient noise emission, the sound energy level) produced by the noise source, in frequency bands of width one-third octave or with frequency weighting A applied,
7、 is calculated using those measurements, including corrections to allow for any differences between the meteorological conditions at the time and place of the test and those corresponding to a reference characteristic acoustic impedance. AMERICAN NATIONAL STANDARDS ON ACOUSTICS The Acoustical Societ
8、y of America (ASA) provides the Secretariat for Accredited Standards Committees S1 on Acoustics, 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, consumer
9、s, trade associations, organizations with a general interest, and government representatives). The 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).
10、 These standards are developed and published as a public service to provide standards useful to the 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
11、 developing, voting upon, and maintaining or revising its own Standards. The ASA Standards Secretariat 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 Stand
12、ards Committees, and approved as American National Standards by ANSI, the ASA Standards Secretariat 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
13、 judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly 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
14、a concerted effort be made towards their resolution. The use of an American National Standard is 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
15、, or procedures not conforming to the Standards. NOTICE: This American National Standard may be revised 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 o
16、f America ASA Secretariat 35 Pinelawn Road, Suite 114E Melville, New York 11747-3177 Telephone: 1 (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 commerc
17、ial purpose, or any purpose not falling within the provisions of the U.S. Copyright Act of 1976, 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
18、ISO, IEC, ANSI, and ASA. No part of this publication may be reproduced in any form, including 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 Ame
19、rica (ASA). 2012 Acoustical Society of AmericaAll rights reserved i Contents 1 Scope . 1 1.1 General . 1 1.2 Types of noise and noise sources 1 1.3 Test room 1 1.4 Measurement uncertainty . 1 2 Normative references . 1 3 Terms and definitions . 2 4 Reference meteorological conditions . 8 5 Test room
20、s . 8 5.1 Acoustic criterion for adequacy of the test room 8 5.2 Criteria for background noise . 9 5.3 Criterion for air temperature . 10 6 Instrumentation 12 6.1 Instruments for acoustical measurements 12 6.2 Instruments for meteorological measurements 12 7 Definition, location, installation and op
21、eration of noise source under test . 13 7.1 General . 13 7.2 Auxiliary equipment 13 7.3 Noise source location . 13 7.4 Mounting of the noise source . 13 7.5 Operation of source during test 14 8 Measurement surface 15 8.1 Spherical measurement surface for use in an anechoic room . 15 8.2 Hemispherica
22、l measurement surface for use in a hemi-anechoic room 15 9 Determination of sound power levels and sound energy levels 17 9.1 Measurements in the test room 17 9.2 Measurement of meteorological conditions 17 9.3 Microphone positions 17 9.4 Determination of sound power levels of a noise source which e
23、mits steady or non-steady noise19 9.5 Determination of sound energy levels for a noise source which emits impulsive noise . 23 9.6 Calculation of directivity indices 26 9.7 Calculation of surface sound pressure level non-uniformity index . 26 9.8 Frequency-weighted sound power level and sound energy
24、 level 27 10 Measurement uncertainty . 27 10.1 Methodology . 27 10.2 Determination of omc28 10.3 Determination of R0. 28 10.4 Typical upper bound values of R029 10.5 Total standard deviation, tot, and expanded measurement uncertainty, U . 30 11 Information to be recorded . 31 11.1 General . 31 ii 20
25、12 Acoustical Society of AmericaAll rights reserved. 11.2 Noise source under test 31 11.3 Test room 31 11.4 Instrumentation . 31 11.5 Acoustical data . 32 12 Test report 32 Annex A (normative) General procedures for qualification of anechoic and hemi-anechoic rooms . 33 A.1 General . 33 A.2 Instrume
26、ntation and measuring equipment 33 A.3 Installation of test sources and microphones . 36 A.4 Test procedures 37 A.5 Qualification procedure . 39 Annex B (normative) Qualification procedure for spaces within test rooms used in the determination of sound power levels and sound energy levels of specifi
27、c noise sources . 41 B.1 General . 41 B.2 Properties of reflecting plane 41 B.3 Procedure using two measurement spheres or hemispheres with different radii (two-surface method) . 42 Annex C (normative) Calculation of A-weighted sound power levels and A-weighted sound energy levels from one-third-oct
28、ave band levels . 43 C.1 A-weighted sound power levels 43 C.2 A-weighted sound energy levels . 43 C.3 Values of j and Cjfor use in calculations 43 Annex D (normative) Array of microphone positions on a spherical measurement surface in a free field 45 Annex E (normative) Arrays of microphone position
29、s on a hemispherical measurement surface in a hemi-free field . 48 Annex F (normative) Coaxial circular paths of microphones on a hemispherical measurement surface in a hemi-free field 53 Annex G (normative) Meridional paths of microphones on a hemispherical measurement surface in a hemi-free field
30、. 54 Annex H (normative) Spiral paths of microphones on a hemispherical measurement surface in a hemi-free field . 56 Annex I (informative) Guidance on the development of information on measurement uncertainty 57 I.1 General . 57 I.2 Considerations on the total standard deviation, tot. 57 I.3 Consid
31、erations on omc. 57 I.4 Considerations on R0. 59 I.5 Combined standard uncertainty 66 I.6 Measurement uncertainty based on reproducibility data 66 I.7 Example of an uncertainty budget for a reference sound source in a national laboratory . 67 2012 Acoustical Society of AmericaAll rights reserved iii
32、 Figures Figure 1 Reference box, center for the measurement surface (when using the geometric center of the source) and characteristic source dimensions for application in an anechoic and a hemi-anechoic room . 16 Figure A.1 Microphone positions on the spherical surface for test sound source directi
33、vity measurements . 35 Figure D.1 Microphone positions on the spherical measurement surface . 47 Figure E.1 Microphone positions on the hemispherical measurement surface (general case) . 51 Figure E.2 Microphone positions on the hemispherical measurement surface for broadband omnidirectional sources
34、 . 52 Figure F.1 Coaxial circular paths for a moving microphone . 53 Figure G.1 Meridional paths for a moving microphone 54 Figure G.2 Example of a mechanical system to realize a meridional path 55 Figure G.3 Example of an electronic control circuit 55 Figure H.1 Spiral path for a moving microphone
35、56 Tables Table 1 Maximum background noise levels in test room for absolute criteria . 11 Table 2 Typical upper bound values of the standard deviation of reproducibility of the method,R0, for sound power levels and sound energy levels determined in a hemi-anechoic room in accordance with this Americ
36、an National Standard . 30 Table 3 Typical upper bound values of the standard deviation of reproducibility of the method, R0, for the sound power levels and sound energy levels determined in an anechoic room, in accordance with this American National Standard . 30 Table A.1 Allowable deviation in dir
37、ectivity of the test source 34 Table A.2 Maximum allowable deviation of measured sound pressure levels from theoretical levels using the inverse square law . 40 Table C.1 Values of j and Cjfor mid-band frequencies of one-third-octave bands 44 Table D.1 Microphone positions . 46 Table E.1 Microphone
38、positions (general case) . 49 Table E.2 Microphone positions for a broadband omnidirectional source . 50 iv 2012 Acoustical Society of AmericaAll rights reserved. Table I.1 Examples of calculated total standard deviations, tot, for three different cases 59 Table I.2 Example of an uncertainty budget
39、for determinations of R0for sound power level and sound energy level, valid for frequencies from 500 Hz to 4 kHz, or for A-weighted measurements of a source with a relatively flat frequency spectrum 62 2012 Acoustical Society of AmericaAll rights reserved v Foreword This Foreword is for information
40、only, and is not a part of the American National Standard ANSI/ASA S12.55-2012 / ISO 3745:2012 American National Standard Acoustics Determination of sound power levels and sound energy levels of noise sources using sound pressure Precision methods for anechoic rooms and hemi-anechoic rooms. This sta
41、ndard 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 Standards Institute (A
42、NSI). 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 acoustics as related to en
43、vironmental and occupational noise. This standard is a revision of ANSI S12.55-2006 / ISO 3745:2003, which has been technically revised. This Standard is identical to International Standard ISO 3745, Acoustics Determination of sound power levels and sound energy levels of noise sources using sound p
44、ressure Precision methods for anechoic rooms and hemi-anechoic rooms, which was prepared by Technical Committee ISO/TC 43 Subcommittee SC 1, Noise. However, in conformance with ANSI and ISO rules, the words “American National Standard“ replace the words “International Standard“ where they appear in
45、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 addition, editorial correction was made to the caption of Figure E.2. In ISO 3745:2012 this figure and the previous o
46、ne were numbered E.1. The ANSI or ANSI/ASA equivalents for the ISO standards in the ISO 3740 series and other referenced nationally adopted standards are given below: ANSI/ASA S12.5 / ISO 6926 is an identical national adoption of ISO 6926; ANSI/ASA S12.50/ISO 3740 is an identical national adoption o
47、f ISO 3740; ANSI/ASA S12.51/ISO 3741 is an identical national adoption of ISO 3741; ANSI/ASA S12.53/Part 1/ISO 3743-1 is an identical national adoption of ISO 3743-1; ANSI/ASA S12.53/Part 2/ISO 3743-2 is an identical national adoption of ISO 3743-2; ANSI/ASA S12.54/ISO 3744 is an identical national
48、adoption of ISO 3744; ANSI/ASA S12.55/ISO 3745 is an identical national adoption of ISO 3745; ANSI/ASA S12.56/ISO 3746 is an identical national adoption of ISO 3746; and ANSI/ASA S12.57/ISO 3747 is an identical national adoption of ISO 3747. At the time this Standard was submitted to Accredited Stan
49、dards Committee S12, Noise for approval, the membership was as follows: W.J. Murphy, Chair S.J. Lind, Vice-Chair S.B. Blaeser, Secretary 3M Occupational Health FAX: 631-390-0217; E-mail: asastdsaip.org. ANSI/ASA S12.55-2012 / ISO 3745:2012 2012 Acoustical Society of AmericaAll rights reserved ixIntroduction This American National Standard is a national adoption of one of the series ISO 37413to ISO 37478, which specify various methods for determining the sound power levels and sou
