1、Electroacoustics Measurement microphonesPart 3: Primary method for free-field calibration of laboratory standard microphones by the reciprocity techniqueBS EN 61094-3:2016Incorporating corrigendum December 2016(IEC 61094-3:2016)BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2
2、013 15:06National forewordThis British Standard is the UK implementation of EN 61094-3:2016. It isidentical to IEC 61094-3:2016, incorporating corrigendum December 2016.The UK participation in its preparation was entrusted to TechnicalCommittee EPL/29, Electroacoustics.A list of organizations repres
3、ented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2017.Published by BSI Standards Limited 2017ISBN 978 0 580 9
4、7575 2ICS 17.140.50; 33.160.50Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 2016.Amendments/corrigenda issued since publicationDate Text affectedBRI
5、TISH STANDARDBS EN 61094-3:2016Implementation of IEC corrigendum December 2016: 28 February 2017subclause 5.7.2 correctedIt supersedes BS EN 61094-3:1996 which is withdrawn.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 61094-3 September 2016 ICS 17.140.50; 33.160.50 Supersedes EN 61094-3:1995
6、 English Version Electroacoustics - Measurement microphones - Part 3: Primary method for free-field calibration of laboratory standard microphones by the reciprocity technique (IEC 61094-3:2016) lectroacoustique - Microphones de mesure - Partie 3: Mthode primaire pour ltalonnage en champ libre des m
7、icrophones talons de laboratoire par la mthode de rciprocit (IEC 61094-3:2016) Messmikrofone - Teil 3: Primrverfahren zur Freifeld-Kalibrierung von Laboratoriums-Normalmikrofonen nach der Reziprozittsmethode (IEC 61094-3:2016) This European Standard was approved by CENELEC on 2016-07-19. CENELEC mem
8、bers are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on applicat
9、ion to the CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELE
10、C Management Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Icela
11、nd, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europis
12、ches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No. EN 61094-3:2016 E BS EN 61094-3:2016EN 61094-3:2016 2 European foreword The
13、 text of document 29/873/CDV, future edition 2 of IEC 61094-3, prepared by IEC TC 29, Electroacoustics, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61094-3:2016. The following dates are fixed: latest date by which the document hasto be implemented at national lev
14、el bypublication of an identical nationalstandard or by endorsement(dop) 2017-04-19 latest date by which the nationalstandards conflicting with thedocument have to be withdrawn(dow) 2019-07-19 This document supersedes EN 61094-3:1995. Attention is drawn to the possibility that some of the elements o
15、f this document may be the subject of patent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 61094-3:2016 was approved by CENELEC as a European Standard without any modification. In
16、the official version, for Bibliography, the following note has to be added for the standard indicated: IEC 61094-8:2012 NOTE Harmonized as EN 61094-8:2012. BS EN 61094-3:2016EN 61094-3:2016 3 Annex ZA (normative) Normative references to international publications with their corresponding European pu
17、blications The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) appli
18、es. NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here: www.cenelec.eu. Publication Year Title EN/HD
19、Year IEC 61094-1 2000 Measurement microphones - Part 1: Specifications for laboratory standard microphones EN 61094-1 2000 IEC 61094-2 2009 Electroacoustics - Measurement microphones - Part 2: Primary method for the pressure calibration of laboratory standard microphones by the reciprocity technique
20、 EN 61094-2 2009 ISO 9613-1 - Acoustics; attenuation of sound during propagation outdoors; part_1: calculation of the absorption of sound by the atmosphere - - IEC/TS 61094-7 - Measurement microphones - Part 7: Values for the difference between free-field and pressure sensitivity levels of laborator
21、y standard microphones - - ISO/IEC Guide 98-3 - Uncertainty of measurement - Part 3: Guide to the expression of uncertainty in measurement (GUM:1995) - - BS EN 61094-3:2016This page deliberately left blankBS EN 61094-3:2016 2 IEC 61094-3:2016 IEC 2016 CONTENTS FOREWORD . 4 1 Scope 6 2 Normative refe
22、rences. 6 3 Terms and definitions 6 4 Reference environmental conditions . 7 5 Principles of free-field calibration by reciprocity 7 5.1 General principles . 7 5.1.1 General . 7 5.1.2 General principles using three microphones 7 5.1.3 General principles using two microphones and an auxiliary sound s
23、ource . 8 5.2 Basic expressions . 8 5.3 Insert voltage technique 9 5.4 Free-field receiving characteristics of a microphone . 9 5.5 Free-field transmitting characteristics of a microphone . 10 5.6 Reciprocity procedure . 11 5.7 Final expressions for the free-field sensitivity . 11 5.7.1 Method using
24、 three microphones 11 5.7.2 Method using two microphones and an auxiliary sound source 12 6 Factors influencing the free-field sensitivity 12 6.1 General . 12 6.2 Polarizing voltage 12 6.3 Shield configuration 12 6.4 Acoustic conditions . 13 6.5 Position of the acoustic centre of a microphone . 13 6
25、.6 Dependence on environmental conditions 14 6.6.1 General . 14 6.6.2 Static pressure . 14 6.6.3 Temperature 14 6.6.4 Humidity 14 6.6.5 Transformation to reference environmental conditions. 14 6.7 Considerations concerning measurement space . 15 7 Calibration uncertainty components 15 7.1 General .
26、15 7.2 Electrical transfer impedance 15 7.3 Deviations from ideal free-field conditions 15 7.4 Attenuation of sound in air . 16 7.5 Polarizing voltage 16 7.6 Physical properties of air . 16 7.7 Imperfection of theory . 16 7.8 Uncertainty on free-field sensitivity level 17 Annex A (informative) Value
27、s for the position of the acoustic centre 19 Annex B (normative) Values of the air attenuation coefficient 20 B.1 General . 20 B.2 Calculation procedure . 20 BS EN 61094-3:2016IEC 61094-3:2016 IEC 2016 3 Annex C (informative) Environmental influence on the sensitivity of microphones 23 C.1 General .
28、 23 C.2 Dependence on static pressure . 23 C.3 Dependence on temperature . 23 Annex D (informative) Application of time selective techniques for removal of unwanted reflections and acoustic interference between microphones . 25 D.1 General . 25 D.2 Practical considerations 25 D.2.1 Signal-to-noise r
29、atio . 25 D.2.2 Reflections from walls and measurement rig . 25 D.3 Frequency limitations 26 D.3.1 General . 26 D.3.2 Measurements based on frequency sweeps 26 D.3.3 Measurements based on pure tones . 26 D.4 Generating missing portions of the frequency response previous to transforming to the time-d
30、omain. . 27 D.4.1 General . 27 D.4.2 Missing frequencies below the minimum measurement frequency 27 D.4.3 Missing frequencies above the maximum measured frequency 27 D.4.4 Filtering the extended frequency response 28 Bibliography . 29 Figure 1 Equivalent circuit for a receiving microphone under free
31、-field conditions . 9 Figure 2 Equivalent circuit for a transmitting microphone under free-field conditions . 10 Figure A.1 Example of the estimated values of the acoustic centres of LS1P and LS2aP microphones given in the bibliographical references for Annex A 19 Table 1 Uncertainty components 17 T
32、able B.1 Values for attenuation of sound pressure in air (in dB/m) . 22 BS EN 61094-3:2016 4 IEC 61094-3:2016 IEC 2016 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ ELECTROACOUSTICS MEASUREMENT MICROPHONES Part 3: Primary method for free-field calibration of laboratory standard microphones by the reci
33、procity technique FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning stan
34、dardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparat
35、ion is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with
36、 the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subje
37、cts since each technical committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical
38、content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent po
39、ssible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide confo
40、rmity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its direc
41、tors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising
42、 out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is dra
43、wn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 61094-3 has been prepared by IEC technical committee 29: Electroacoustics. This sec
44、ond edition cancels and replaces the first edition published in 1995. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) a new informative annex describing the use of time-selective techniques to m
45、inimize the influence of acoustic reflections from the measurement setup; b) provision for the calibration of microphones in driven shield configuration. BS EN 61094-3:2016IEC 61094-3:2016 IEC 2016 5 The text of this standard is based on the following documents: CDV Report on voting 29/873/CDV 29/89
46、2A/RVC Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all parts in the IEC 61094 series, published under the general tit
47、le Electroacoustics Measurement microphones, can be found on the IEC website. The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific publication. At
48、this date, the publication will be reconfirmed, withdrawn, replaced by a revised edition, or amended. IMPORTANT The colour inside logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users shoul
49、d therefore print this document using a colour printer. BS EN 61094-3:2016 6 IEC 61094-3:2016 IEC 2016 ELECTROACOUSTICS MEASUREMENT MICROPHONES Part 3: Primary method for free-field calibration of laboratory standard microphones by the reciprocity technique 1 Scope This part of IEC 61094 specifies a primary method of determining the complex free-field sensitivity of laboratory standard microphones so as to establish a reproducible and accurate basis for the measurement of sou
