1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationElectroacoustics Measurement microphonesPart 8: Methods for free-field calibrationof working standard microphones bycomparisonBS EN 61094-8:2012BS EN 61094-8:2012Incorporating co
2、rrigendum May 2013Part 8: Methods for determining thefree-field sensitivity of working standardmicrophones by comparison National forewordThis British Standard is the UK implementation of EN 61094-8:2012. It is identical to IEC 61094-8:2012.The UK participation in its preparation was entrusted to Te
3、chnical Committee EPL/29, Electroacoustics.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 Standar
4、ds Institution 2012.Published by BSI Standards Limited 2012ISBN 978 0 580 77250 4 ICS 17.140.50Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on 31 January 2013.Amen
5、dments issued since publicationDate Text affectedBRITISH STANDARDBS EN 61094-8:2012BS EN 61094-8:2012 BRITISH STANDARDitis St ndard is the UK implementation of EN 61094-8:2012 ncorporating corrigendum 013. It is identical to IEC 61094-8:2012.ritish Standards Ins itution 2013. Published by BSI Standa
6、rds Limited 2013ISBN 978 0 580 82031 1 ICS 17.140.50Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 May 2013.Amendments/corrigenda issued since publicationDate
7、 Text affected31 May 2013 Implementation of CENELEC corrigendum January 2013: Standard title correctedNational forewordThis British Standard is the UK implementation of EN 61094-8:2012. It is identical to IEC 61094-8:2012.The UK participation in its preparation was entrusted to Technical Committee E
8、PL/29, Electroacoustics.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 Standards Institution 2012
9、.Published by BSI Standards Limited 2012 ISBN 978 0 580 77250 4 ICS 17.140.50Compliance 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 31 January 2013.Amendments issued si
10、nce publicationDate Text affectedBRITISH STANDARDBS EN 61094-8:2012 EUROPEAN STANDARD EN 61094-8 NORME EUROPENNE EUROPISCHE NORM November 2012 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Norm
11、ung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2012 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61094-8:2012 E ICS 17.140.50 English version Electroacoustics - Measurement microphones - Part 8: Methods for free-fie
12、ld calibration of working standard microphones by comparison (IEC 61094-8:2012) Electroacoustique - Microphones de mesure - Partie 8: Mthodes pour ltalonnage en champ libre par comparaison des microphones talons de travail (CEI 61094-8:2012) Elektroakustik - Messmikrofone - Teil 8: Verfahren zur Erm
13、ittlung des Freifeld-bertragungskoeffizienten von Gebrauchs-Normalmikrofonen nach der Vergleichsmethode (IEC 61094-8:2012) This European Standard was approved by CENELEC on 2012-10-24. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for gi
14、ving 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 application to the CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in thre
15、e 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-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national elect
16、rotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Rom
17、ania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 61094-8:2012Incorporating corrigendum January 2013Part 8: Methods for determining the free-field sensitivity of working standard microphones by comparison(IEC 61094-8:2012)Electroacoustique -Microphones de mes
18、ure -Partie 8: Mthodes pour la dtermination de lefficacit en champ libre par comparaison des microphones talons de travail(CEI 61094-8:2012)Elektroakustik -Messmikrofone -eil 8: Verfahren zur Ermittlung des Freifeld-bertragungskoeffizienten von Gebrauchs-Normalmikrofonen nach der Vergleichsmethode (
19、IEC 61094-8:2012)EN 61094-8:2012 - 2 - Foreword The text of document 29/752/CDV, future edition 1 of IEC 61094-8, prepared by IEC/TC 29 “IEC TC 29, Electroacoustics“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61094-8:2012. The following dates are fixed: latest date
20、by which the document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2013-07-24 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2015-10-24 Attention is drawn to the possibility that
21、 some of the elements of 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 61094-8:2012 was approved by CENELEC as a European Standard withou
22、t any modification. BS EN 61094-8:2012- 3 - EN 61094-8:2012 Annex ZA (normative) Normative references to international publicationswith their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and areindispensable for its app
23、lication. For dated references, only the edition cited applies. For undatedreferences, the latest edition of the referenced document (including any amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HDapplies. Pu
24、blication Year Title EN/HD Year IEC 61094-1 - Measurement microphones - Part 1: Specifications for laboratory standardmicrophones EN 61094-1 - IEC 61094-2 - Electroacoustics - Measurement microphones - Part 2: Primary method for the pressurecalibration of laboratory standardmicrophones by the recipr
25、ocity technique EN 61094-2 - IEC 61094-3 - Measurement microphones - Part 3: Primary method for free-fieldcalibration of laboratory standardmicrophones by the reciprocity technique EN 61094-3 - IEC 61094-4 - Measurement microphones - Part 4: Specifications for working standardmicrophones EN 61094-4
26、- IEC 61094-5 - Measurement microphones - Part 5: Methods for pressure calibration ofworking standard microphones bycomparison EN 61094-5 - IEC 61094-6 - Measurement microphones - Part 6: Electrostatic actuators fordetermination of frequency response EN 61094-6 - IEC/TS 61094-7 - Measurement microph
27、ones - Part 7: Values for the difference betweenfree-field and pressure sensitivity levels oflaboratory standard microphones - - ISO/IEC Guide 98-3 - Uncertainty of measurement - Part 3: Guide to the expression ofuncertainty in measurement (GUM:1995) - - ISO 26101 - Acoustics - Test methods for the
28、qualificationof free-field environments - - BS EN 61094-8:2012 2 61094-8 IEC:2012 CONTENTS 1 Scope . 6 2 Normative references . 6 3 Terms and definitions . 7 4 Reference environmental conditions . 8 5 Principles of free-field calibration by comparison 8 5.1 General principle . 8 5.2 General principl
29、es using sequential excitation . 8 5.3 General principles using simultaneous excitation . 8 6 General requirements . 9 6.1 The test space . 9 6.2 Methods of establishing the free-field 9 6.2.1 General . 9 6.2.2 Using a test space with sound absorbing surfaces . 9 6.2.3 Time selective methods for obt
30、aining the free-field sensitivity 10 6.3 The sound source 10 6.4 Reference microphone 11 6.5 Monitor microphone . 12 6.6 Test signals . 12 6.7 Configuration for the reference microphone and microphone under test 13 7 Factors influencing the free-field sensitivity 13 7.1 General . 13 7.2 Polarizing v
31、oltage 13 7.3 Acoustic centre of the microphone . 13 7.4 Angle of incidence and alignment with the sound source . 14 7.5 Mounting configuration 14 7.6 Dependence on environmental conditions 14 8 Calibration uncertainty components 14 8.1 General . 14 8.2 Sensitivity of the reference microphone . 15 8
32、.3 Measurement of the microphone output . 15 8.4 Differences between the sound pressure applied to the reference microphone and to the microphone under test . 15 8.5 Influence of indirect sound 15 8.6 Influence of signal processing . 16 8.7 Influence of microphone characteristics and measurement sys
33、tem performance 16 8.7.1 Microphone capacitance 16 8.7.2 Measurement system non-linearity 16 8.7.3 Validation of calibration system . 16 8.8 Uncertainty on free-field sensitivity level 16 Annex A (informative) Basic substitution calibration in a free-field chamber . 18 Annex B (informative) Time sel
34、ective techniques . 22 Bibliography 30 BS EN 61094-8:2012 2 61094-8 IEC:2012 CONTENTS 1 Scope . 6 2 Normative references . 6 3 Terms and definitions . 7 4 Reference environmental conditions . 8 5 Principles of free-field calibration by comparison 8 5.1 General principle . 8 5.2 General principles us
35、ing sequential excitation . 8 5.3 General principles using simultaneous excitation . 8 6 General requirements . 9 6.1 The test space . 9 6.2 Methods of establishing the free-field 9 6.2.1 General . 9 6.2.2 Using a test space with sound absorbing surfaces . 9 6.2.3 Time selective methods for obtainin
36、g the free-field sensitivity 10 6.3 The sound source 10 6.4 Reference microphone 11 6.5 Monitor microphone . 12 6.6 Test signals . 12 6.7 Configuration for the reference microphone and microphone under test 13 7 Factors influencing the free-field sensitivity 13 7.1 General . 13 7.2 Polarizing voltag
37、e 13 7.3 Acoustic centre of the microphone . 13 7.4 Angle of incidence and alignment with the sound source . 14 7.5 Mounting configuration 14 7.6 Dependence on environmental conditions 14 8 Calibration uncertainty components 14 8.1 General . 14 8.2 Sensitivity of the reference microphone . 15 8.3 Me
38、asurement of the microphone output . 15 8.4 Differences between the sound pressure applied to the reference microphone and to the microphone under test . 15 8.5 Influence of indirect sound 15 8.6 Influence of signal processing . 16 8.7 Influence of microphone characteristics and measurement system p
39、erformance 16 8.7.1 Microphone capacitance 16 8.7.2 Measurement system non-linearity 16 8.7.3 Validation of calibration system . 16 8.8 Uncertainty on free-field sensitivity level 16 Annex A (informative) Basic substitution calibration in a free-field chamber . 18 Annex B (informative) Time selectiv
40、e techniques . 22 Bibliography 30 BS EN 61094-8:201261094-8 IEC:2012 3 Figure A.1 Illustration of source and receiver setup in a free-field room, where the monitor microphone has been integrated into the loudspeaker 18 Figure A.2 Practical implementation in a hemi-anechoic room with a source flush-m
41、ounted in the floor 19 Figure A.3 Examples of loudspeaker sources . 21 Figure B.1 Illustration of set-up for measurement with time selective techniques 23 Table 1 Calibration options for the reference microphone and associated typical measurement uncertainty 12 Table 2 Typical uncertainty components
42、 17 BS EN 61094-8:2012 6 61094-8 IEC:2012 MEASUREMENT MICROPHONES Part 8: Methods for determining the free-field sensitivity of working standard microphones by comparison 1 Scope This part of the IEC 61094 series is applicable to working standard microphones meeting the requirements of IEC 61094-4.
43、It describes methods of determining the free-field sensitivity by comparison with a laboratory standard microphone or working standard microphone (where applicable) that has been calibrated according to either: IEC 61094-3, IEC 61094-2 or IEC 61094-5, and where factors given in IEC/TS 61094-7 have b
44、een applied, IEC 61094-6, this part of IEC 61094. Methods performed in an acoustical environment that is a good approximation to an ideal free-field (e.g. a high quality free-field chamber), and methods that use post processing of results to minimise the effect of imperfections in the acoustical env
45、ironment, to simulate free-field conditions, are both covered by this part of IEC 61094. Comparison methods based on the principles described in IEC 61094-3 are also possible but beyond the scope of this part of IEC 61094. NOTE 1 This part of IEC 61094 is also applicable to laboratory standard micro
46、phones meeting the requirements of IEC 61094-1, noting that these microphones also meet the electroacoustic specifications for working standard microphones. NOTE 2 This part of IEC 61094 is also applicable to combinations of microphone and preamplifier where the determined sensitivity is referred to
47、 the unloaded output voltage of the preamplifier. NOTE 3 Other devices, for example, sound level meters can be calibrated using the principles of this part of IEC 61094, but are not within the scope of this standard. 2 Normative references The following documents, in whole or in part, are normativel
48、y 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) applies. IEC 61094-1, Measurement microphones Part 1: Specifications for lab
49、oratory standard microphones IEC 61094-2, Electroacoustics Measurement microphones Part 2: Primary method for pressure calibration of laboratory standard microphones by the reciprocity technique IEC 61094-3, Measurement microphones Part 3: Primary method for free-field calibration of laboratory standard microphones by the reciprocity technique IEC 61094-4, Measurement microphones Part 4: Specifications for working standard microphones BS EN 61094-8:2012 6 61094-8 IEC:2012 MEASUREMENT MI
