1、Acoustics Test methods for the qualification of free-field environmentsBS ISO 26101:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06 ISO 2017Acoustics Test methods for the qualification of free-field environmentsAcoustique Mthodes dessai pour la qualification des
2、 environnements en champ libreINTERNATIONAL STANDARDISO26101Second edition2017-04Reference numberISO 26101:2017(E)National forewordThis British Standard is the UK implementation of ISO 26101:2017. It supersedes BS ISO 26101:2012, which is withdrawn.The UK participation in its preparation was entrust
3、ed to Technical Committee EH/1, Acoustics.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standard
4、s Institution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 92051 6ICS 17.140.01Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2017.Amendme
5、nts/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS ISO 26101:2017 ISO 2017Acoustics Test methods for the qualification of free-field environmentsAcoustique Mthodes dessai pour la qualification des environnements en champ libreINTERNATIONAL STANDARDISO26101Second edition2017-
6、04Reference numberISO 26101:2017(E)BS ISO 26101:2017ISO 26101:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by an
7、y means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401C
8、H-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 26101:2017ISO 26101:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publ
9、ication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the coun
10、try of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgISO 26101:2017(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Allowable deviations fr
11、om inverse square law . 25 Measurement of free sound field performance 35.1 Divergence loss method 35.1.1 Principle 35.1.2 Instrumentation and measuring equipment . 35.1.3 Location of test sound sources and microphone traverses . 45.1.4 Test procedure . 55.1.5 Expression of results 65.1.6 Measuremen
12、t uncertainty . 75.2 Information to be recorded 75.3 Information to be reported 8Annex A (normative) Qualification criteria and measurement requirements . 9Annex B (normative) General procedure for evaluation of sound source directionality .12Annex C (informative) Measurement uncertainty .15Annex D
13、(informative) Guidelines for referring to this test method 18Bibliography .20 ISO 2017 All rights reserved iiiContents PageBS ISO 26101:2017ISO 26101:2017(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). Th
14、e work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-gov
15、ernmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described i
16、n the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).Attention is drawn to th
17、e possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO
18、list of patent declarations received (see www .iso .org/ patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as
19、 well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.The committee responsible for this document is ISO/TC 43, Acoustics.This second edition cancels and replaces t
20、he first edition (ISO 26101:2012), which has been technically revised. The main changes are as follows: the term “acoustic centre” was replaced by “mathematical origin of the traverse” in several places in the document to provide clarification of terminology; the minimum traverse path length was red
21、uced from 1/2 wavelength to 1/4 wavelength; Figure B.1 has been added.iv ISO 2017 All rights reservedBS ISO 26101:2017ISO 26101:2017(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing In
22、ternational Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison
23、with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directiv
24、es, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).Attention is drawn to the possibility that som
25、e of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declara
26、tions received (see www .iso .org/ patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information a
27、bout ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.The committee responsible for this document is ISO/TC 43, Acoustics.This second edition cancels and replaces the first edition (ISO
28、26101:2012), which has been technically revised. The main changes are as follows: the term “acoustic centre” was replaced by “mathematical origin of the traverse” in several places in the document to provide clarification of terminology; the minimum traverse path length was reduced from 1/2 waveleng
29、th to 1/4 wavelength; Figure B.1 has been added.iv ISO 2017 All rights reserved ISO 26101:2017(E)IntroductionThis document describes the divergence loss method of measurement of performance of an environment designed to provide a free sound field or free sound field over a reflecting plane. An acous
30、tical environment is a free sound field if it has bounding surfaces that absorb all sound energies incident upon them. This is normally achieved using specialized test environments, such as anechoic or hemi-anechoic chambers. In practice, these provide a controlled free sound field for acoustical me
31、asurements in a confined space within the facility.The purpose of this document is to promote uniformity in the method and conditions of measurement when qualifying free sound field environments.It is expected that the qualification procedures outlined in this document will be referred to by other I
32、nternational Standards and industry test codes. In such cases, these documents making reference to this document may specify qualification criteria appropriate for the test method and may require specific traverse paths. ISO 2017 All rights reserved vBS ISO 26101:2017BS ISO 26101:2017Acoustics Test
33、methods for the qualification of free-field environments1 ScopeThis document specifies methodology for qualifying acoustic spaces as anechoic and hemi-anechoic spaces meeting the requirements of a free sound field.This document specifies discrete-frequency and broad-band test methods for quantifying
34、 the performance of anechoic and hemi-anechoic spaces, defines the qualification procedure for an omni-directional sound source suitable for free-field qualification, gives details of how to present the results and describes uncertainties of measurement.This document has been developed for qualifyin
35、g anechoic and hemi-anechoic spaces for a variety of acoustical measurement purposes. It is expected that, over time, various standards and test codes will refer to this document in order to qualify an anechoic or hemi-anechoic space for a particular measurement.In the absence of specific requiremen
36、ts or criteria, Annex A provides qualification criteria and measurement requirements to qualify anechoic and hemi-anechoic spaces for general purpose acoustical measurements.This document describes the divergence loss method for measuring the free sound field performance of an acoustic environment.2
37、 Normative referencesThe following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including a
38、ny amendments) applies.ISO/IEC Guide 98-3, Uncertainty of measurement Part 3: Guide to the expression of uncertainty in measurement (GUM: 1995)IEC 61260-1, Electroacoustics Octave-band and fractional-octave-band filters Part 1: SpecificationsIEC 61672-1, Electroacoustics Sound level meters Part 1: S
39、pecifications3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at h t t p :/ www .electropedia .org/ ISO Online browsing
40、platform: available at h t t p :/ www .iso .org/ obp3.1free sound fieldsound field in a homogeneous, isotropic medium free of boundariesSOURCE: ISO/TR 25417:2007, 2.17INTERNATIONAL STANDARD ISO 26101:2017(E) ISO 2017 All rights reserved 1BS ISO 26101:2017ISO 26101:2017(E)3.2anechoic spacevolume whic
41、h has been qualified as a sound field in a homogeneous, isotropic medium free of boundaries3.3hemi-anechoic spacevolume above a reflecting plane which has been qualified as a sound field in a homogeneous, isotropic medium free of boundaries3.4acoustic centreposition of the point from which approxima
42、tely spherical wave fronts appear to diverge3.5background noisesum of all the signals except the one under investigationNote 1 to entry: Background noise can include contributions from airborne sound, structure-borne vibration and electrical noise in instrumentation.3.6divergence lossreduction in so
43、und pressure along a straight path due to the spreading of sound when a sound wave propagates away from a source3.7frequency range of interestcontiguous one-third-octave-band frequencies from the lowest to the highest frequencies to be qualified, inclusive3.8referencing documentstandard or test code
44、 that refers to this document for the purpose of specifying the qualification method of an anechoic (3.2) or hemi-anechoic space (3.3)4 Allowable deviations from inverse square lawThe theoretical reduction in mean-square sound pressure along a straight path due to spherical propagation of a sound wa
45、ve in a free sound field shall be hereafter referred to as the inverse square law.For a space to be deemed anechoic or hemi-anechoic, as defined by criteria in a referencing document, the deviations of the measured sound pressure levels from those estimated using the inverse square law, obtained acc
46、ording to this document, shall not exceed the values specified by the referencing document.In the absence of specific criteria for the allowable deviations in a referencing document, the criteria in Annex A shall be used to qualify anechoic and hemi-anechoic spaces for general purpose acoustical mea
47、surements.The allowable deviations specified by a referencing document may be more or less stringent than the criteria given in Annex A.2 ISO 2017 All rights reservedBS ISO 26101:2017ISO 26101:2017(E)3.2anechoic spacevolume which has been qualified as a sound field in a homogeneous, isotropic medium
48、 free of boundaries3.3hemi-anechoic spacevolume above a reflecting plane which has been qualified as a sound field in a homogeneous, isotropic medium free of boundaries3.4acoustic centreposition of the point from which approximately spherical wave fronts appear to diverge3.5background noisesum of al
49、l the signals except the one under investigationNote 1 to entry: Background noise can include contributions from airborne sound, structure-borne vibration and electrical noise in instrumentation.3.6divergence lossreduction in sound pressure along a straight path due to the spreading of sound when a sound wave propagates away from a source3.7frequency range of interestcontiguous one-third-octave-band frequencies from the lowest to the highest frequencies to be qualified, inclusive3.8referencing documentstandard
