SANS 61094-1-2009 Measurement microphones Part 1 Specifications for laboratory standard microphones《测量麦克风 第1部分 实验室标准麦克风规范》.pdf

1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-22291-8 SANS 61094-1:2009Edition 1IEC 61094-1:2000Edition 2SOUTH AFRICAN NATIONAL STANDARD Measurement microphones Part 1: Specifications

4、for laboratory standard microphones This national standard is the identical implementation of IEC 61094-1:2000 and is adopted with the permission of the International Electrotechnical Commission. Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27

5、 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 61094-1:2009 Edition 1 IEC 61094-1:2000 Edition 2 Table of changes Change No. Date Scope National foreword This South African standard was approved by National Committee SABS TC 76, Acoustics, electro-acoustics and vibration, in accordance w

6、ith procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in July 2009. NORMEINTERNATIONALECEIIECINTERNATIONALSTANDARD61094-1Deuxime ditionSecond edition2000-07Microphones de mesure Partie 1:Spcifications des microphones talo

7、nsde laboratoireMeasurement microphones Part 1:Specifications for laboratory standardmicrophonesCommission Electrotechnique InternationaleInternational Electrotechnical CommissionPour prix, voir catalogue en vigueurFor price, see current catalogue IEC 2000 Droits de reproduction rservs Copyright - a

8、ll rights reservedAucune partie de cette publication ne peut tre reproduite niutilise sous quelque forme que ce soit et par aucun procd,lectronique ou mcanique, y compris la photocopie et lesmicrofilms, sans laccord crit de lditeur.No part of this publication may be reproduced or utilized inany form

9、 or by any means, electronic or mechanical,including photocopying and microfilm, without permission inwriting from the publisher.International Electrotechnical Commission 3, rue de Varemb Geneva, SwitzerlandTelefax: +41 22 919 0300 e-mail: inmailiec.ch IEC web site http:/www.iec.chCODE PRIXPRICE COD

10、ENSANS 61094-1:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61094-1 IEC:2000 3 CONTENTSPageFOREWORD . 5Clause1 Scope 72 Normative references. 73 Terms and definitions. 74 Reference environmental conditions 135 Classification of laborat

11、ory standard microphone . 135.1 General. 135.2 Type designation 156 Characteristics of laboratory standard microphones . 156.1 Sensitivity. 156.2 Acoustic impedance 156.2.1 General. 156.2.2 Equivalent volume of a microphone. 156.3 Upper limit of the dynamic range of a microphone. 176.4 Static pressu

12、re dependence of microphone sensitivity 176.5 Temperature dependence of microphone sensitivity 176.6 Humidity dependence of microphone sensitivity 176.7 Electrical insulation resistance 196.8 Stability of microphone sensitivity . 196.9 Pressure-equalizing leakage. 197 Specifications 197.1 Mechanical

13、 dimensions. 197.2 Ground shield reference configuration 237.3 Electroacoustical specifications 257.4 Identification markings 27SANS 61094-1:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61094-1 IEC:2000 5 INTERNATIONAL ELECTROTECHNICAL

14、 COMMISSION_MEASUREMENT MICROPHONES Part 1: Specifications for laboratory standard microphonesFOREWORD1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprisingall national electrotechnical committees (IEC National Committees). The object of the

15、 IEC is to promoteinternational co-operation on all questions concerning standardization in the electrical and electronic fields. Tothis end and in addition to other activities, the IEC publishes International Standards. Their preparation isentrusted to technical committees; any IEC National Committ

16、ee interested in the subject dealt with mayparticipate in this preparatory work. International, governmental and non-governmental organizations liaisingwith the IEC also participate in this preparation. The IEC collaborates closely with the InternationalOrganization for Standardization (ISO) in acco

17、rdance with conditions determined by agreement between thetwo organizations.2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, aninternational consensus of opinion on the relevant subjects since each technical committee has representationfrom all in

18、terested National Committees.3) The documents produced have the form of recommendations for international use and are published in the formof standards, technical specifications, technical reports or guides and they are accepted by the NationalCommittees in that sense.4) In order to promote internat

19、ional unification, IEC National Committees undertake to apply IEC InternationalStandards transparently to the maximum extent possible in their national and regional standards. Anydivergence between the IEC Standard and the corresponding national or regional standard shall be clearlyindicated in the

20、latter.5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for anyequipment declared to be in conformity with one of its standards.6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subjectof p

21、atent rights. The IEC shall not be held responsible for identifying any or all such patent rights.International Standard IEC 61094-1 has been prepared by IEC technical committee 29:Electroacoustics.This second edition cancels and replaces the first edition and corrigendum published in 1992.This seco

22、nd edition constitutes a technical revision.The text of this standard is based on the first edition, the corrigendum and the followingdocuments:FDIS Report on voting29/452/FDIS 29/461/RVDFull information on the voting for the approval of this standard can be found in the report onvoting indicated in

23、 the above table.This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.The committee has decided that this publication remains valid until 2005. At this date, inaccordance with the committees decision, the publication will be: reconfirmed; withdrawn; replaced by a revis

24、ed edition, or amended.SANS 61094-1:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61094-1 IEC:2000 7 MEASUREMENT MICROPHONES Part 1: Specifications for laboratory standard microphones1 ScopeThis part of IEC 61094 specifies mechanical di

25、mensions and certain electroacousticcharacteristics for condenser microphones used as laboratory standards for the realizationof the unit of sound pressure and for sound pressure measurements of the highestattainable accuracy. The specifications are intended to ensure that primary calibration bythe

26、reciprocity method can be readily carried out.This part also establishes a system for classifying laboratory standard condenser micro-phones into a number of types according to their dimensions and properties in order tofacilitate the specification of calibration methods, the conducting of inter-lab

27、oratorycomparisons involving the calibration of the same microphones in different laboratories, andthe interchangeability of microphones in a given calibration system.2 Normative referencesThe following normative documents contain provisions which, through reference in this text,constitute provision

28、s of this part of IEC 61094. For dated references, subsequentamendments to, or revisions of, any of these publications do not apply. However parties toagreements based on this part of IEC 61094 are encouraged to investigate the possibility ofapplying the most recent editions of the normative documen

29、ts indicated below. For undatedreferences, the latest edition of the normative document referred to applies. Members of ISOand IEC maintain registers of currently valid International Standards.IEC 60050(801):1994, International Electrotechnical Vocabulary (IEV) Chapter 801:Acoustics and electroacous

30、ticsASME B1.1:1989, Unified inch screw threads (UN and UNR thread form) 13 Terms and definitionsFor the purposes of this part of IEC 61094, the following definitions apply.Remark The underlined symbols are complex quantities.3.1condenser microphonesmicrophone that operates by variation of electrical

31、 capacitanceIEV 801-26-13.NOTE Only condenser microphones operating by a virtually constant charge obtained from an external polarizingvoltage applied from a source of suitably high internal resistance are considered.1(American Society of Mechanical Engineers) Reference is given to ASME B1.1 in the

32、absence of an equivalentinternational standard.SANS 61094-1:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61094-1 IEC:2000 9 3.2laboratory standard microphonecondenser microphone capable of being calibrated to a very high accuracy by a

33、primarymethod such as the closed coupler reciprocity method, and meeting certain severerequirements on mechanical dimensions and electroacoustical characteristics, especially withrespect to stability in time and dependence on environmental conditions3.3open-circuit voltagealternating voltage appeari

34、ng at the electrical output terminals of a microphone as measuredby the insert voltage technique when the microphone is attached to the ground shieldconfiguration specified in 7.2 but is otherwise unloadedUnit: volt, VNOTE Owing to the capacitive nature of the microphone, the voltage at the electric

35、al terminals depends on the electricalload presented by the mechanical and electrical attachment of the microphone to a preamplifier. For this reason,preamplifiers used for measuring the open-circuit voltage of a microphone should fulfill the requirements of 7.2.3.4pressure sensitivity of a micropho

36、nefor a sinusoidal signal of given frequency and for given environmental conditions, the quotientof the open-circuit voltage of the microphone by the sound pressure acting over the exposedsurface of the diaphragm (i.e. at the acoustical terminals of the microphone), the soundpressure being uniformly

37、 applied over the surface of the diaphragm. This quotient is acomplex quantity, but when phase information is of no interest the pressure sensitivity maydenote its modulus onlyUnit: volt per pascal, V/Pa3.5pressure sensitivity level of a microphonelogarithm of the ratio of the modulus of the pressur

38、e sensitivity |Mp| to a reference sensitivity.The pressure sensitivity level in decibels is 20 lg (|Mp| / Mr), where the reference sensitivity Mris 1 V/PaUnit: decibel, dB3.6free-field sensitivity of a microphonefor a sinusoidal plane progressive sound wave of given frequency, for a specified direct

39、ion ofincidence, and for given environmental conditions, the quotient of the open-circuit voltage ofthe microphone by the sound pressure that would exist at the position of the acoustic centreof the microphone in the absence of the microphone. This quotient is a complex quantity, butwhen phase infor

40、mation is of no interest, the free-field sensitivity may denote its modulus onlyUnit: volt per pascal, V/PaNOTE 1 At frequencies sufficiently low for the disturbance of the sound field by the microphone to be negligible,the free-field sensitivity approaches the pressure sensitivity (see 6.9 for prac

41、tical limitations).NOTE 2 The position of the acoustic centre is a function of frequency.3.7free-field sensitivity level of a microphonelogarithm of the ratio of the modulus of the free-field sensitivity |Mf| to a reference sensitivity.The free-field sensitivity level in decibels is 20 lg (|Mf| / Mr

42、), where the reference sensitivity Mris 1 V/PaUnit: decibel, dBSANS 61094-1:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61094-1 IEC:2000 11 3.8diffuse-field sensitivity of a microphonefor a sinusoidal signal of given frequency in a di

43、ffuse sound field and for given environmentalconditions, the quotient of the open-circuit voltage of the microphone by the sound pressurethat would exist at the position of the acoustic centre of the microphone in the absence of themicrophoneUnit: volt per pascal, V/PaNOTE 1 At frequencies sufficien

44、tly low for the disturbance of the sound field by the microphone to be negligible,the diffuse-field sensitivity approaches the pressure sensitivity (see 6.9 for practical limitations).NOTE 2 The position of the acoustic centre is a function of frequency.3.9diffuse-field sensitivity level of a microp

45、honelogarithm of the ratio of the modulus of the diffuse-field sensitivity |Md| to a referencesensitivity. The diffuse-field sensitivity level in decibels is 20 lg (|Md| / Mr), where thereference sensitivity Mris 1 V/PaUnit: decibel, dB3.10electrical impedance of a microphonefor a sinusoidal signal

46、of given frequency, the complex quotient of the voltage applied acrossthe electrical terminals of the microphone by the resulting current through those terminals.The microphone shall be connected to the ground-shield configuration specified in 7.2Unit: ohm, NOTE This impedance is a function of the a

47、coustical load on the diaphragm.3.11acoustic impedance of a microphonefor a sinusoidal signal of given frequency, the complex quotient of the sound pressure by thevolume velocity at the diaphragm, the sound pressure being uniformly distributed over thesurface of the diaphragm and the electrical term

48、inals being loaded with an infinite impedanceUnit: pascal second per cubic metre, Pas/m3.12static pressure coefficient of microphone pressure sensitivity levelfor a given frequency, the quotient of the incremental change of pressure sensitivity level bythe incremental change in static pressure produ

49、cing the change in sensitivityUnit: decibel per pascal, dB/PaNOTE The static pressure coefficient is a function of frequency as well as static pressure.3.13temperature coefficient of microphone pressure sensitivity levelfor a given frequency, the quotient of the incremental change of pressure sensitivity level bythe incremental change in temperature producing the change in sensitivityUnit: decibel per kelvin, dB/KNOTE The temperature coefficient is a function of frequency as well as temperature.SANS 61094-1:2