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 978-0-626-22887-3 SANS 61094-6:2009Edition 1IEC 61094-6:2004Edition 1SOUTH AFRICAN NATIONAL STANDARD Measurement microphones Part 6: Electrostatic a
4、ctuators for determination of frequency response This national standard is the identical implementation of IEC 61094-6:2004 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
5、 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 61094-6:2009 Edition 1 IEC 61094-6:2004 Edition 1 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
6、 accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in October 2009. NORME INTERNATIONALECEIIECINTERNATIONAL STANDARD 61094-6Premire ditionFirst edition2004-11Microphones de mesure Partie 6: Grilles dentran
7、ement pour la dtermination de la rponse en frquence Measurement microphones Part 6: Electrostatic actuators for determination of frequency response Pour prix, voir catalogue en vigueur For price, see current catalogue IEC 2004 Droits de reproduction rservs Copyright - all rights reserved Aucune part
8、ie de cette publication ne peut tre reproduite ni utilise sous quelque forme que ce soit et par aucun procd, lectronique ou mcanique, y compris la photocopie et les microfilms, sans laccord crit de lditeur. No part of this publication may be reproduced or utilized in any form or by any means, electr
9、onic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Electrotechnical Commission, 3, rue de Varemb, PO Box 131, CH-1211 Geneva 20, SwitzerlandTelephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmailiec.ch Web: www.iec.c
10、h CODE PRIX PRICE CODE U Commission Electrotechnique InternationaleInternational Electrotechnical Commission SANS 61094-6:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61094-6 IEC:2004 3 CONTENTS FOREWORD.7 1 Scope.11 2 Normative refere
11、nces .11 3 Terms and definitions .13 4 Reference environmental conditions .13 5 Principle of electrostatic actuator operation 13 5.1 General .13 5.2 Electrostatic pressure15 5.3 Electrostatic actuator response .21 6 Actuator design 23 6.1 General .23 6.2 Design.23 7 Validation .25 7.1 General .25 7.
12、2 Repeatability of measurements .25 7.3 Uniformity of actuators of a given model25 7.4 Uniformity of the difference between actuator and pressure response levels .25 8 Measurement of electrostatic actuator response.27 8.1 System for measurement of electrostatic actuator response 27 8.2 Uncertainty c
13、omponents 29 9 Applications of an electrostatic actuator .33 9.1 General .33 9.2 Verification of the frequency response of a measurement system33 9.3 Determination of the environmental characteristics of microphone measurement systems.33 9.4 Determination of free-field and pressure frequency respons
14、es.35 9.5 Measurement of actuator response at very high frequencies .35 Annex A (informative) Examples of electrostatic actuator designs37 Annex B (informative) Set-up for measuring electrostatic actuator response 43 Annex C (informative) Typical uncertainty analysis 45 Annex D (informative) Differe
15、nce between free-field-, pressure- and actuator responses for typical models of measurement microphones.51 Figure 1 Principle of microphone and electrostatic actuator .17 Figure 2 Lumped parameter model of a measurement microphone excited by an electrostatic actuator 21 Figure A.1 Example of electro
16、static actuator for type WS1 microphones 37 Figure A.2 Example of an electrostatic actuator for type WS2 microphones .39 Figure A.3 Examples of electrostatic actuators forming integral parts of the microphone protection grids41 Figure A.4 Example of an electrostatic actuator combined with weather-re
17、sistant protection .41 SANS 61094-6:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61094-6 IEC:2004 5 Figure B.1 Typical set-up for measuring the electrostatic actuator response of a microphone.43 Figure D.1 Examples of differences betwe
18、en relative pressure and actuator frequency responses for four different type of measurement microphone: WS1P (a), WS1F (b) of nominal sensitivities 26 dB re 1V/Pa and WS2P (c) and WS2F (d) of nominal sensitivities 38 dB re 1V/Pa .51 Figure D.2 Examples of differences between relative free-field and
19、 actuator frequency responses for type WS1, WS2 and WS3 microphones when used without protection grids.51 Figure D.3 Example of model dependent difference between relative free field and actuator frequency responses for a type WS2 microphone when used with its protection grid.53 Figure D.4 Example o
20、n the determination of a relative free-field frequency response b) by adding the model dependent free-field to actuator difference as shown in Figure D.3 to the electrostatic actuator response of a microphone a) .53 Table C.1 Uncertainties .49 SANS 61094-6:2009This s tandard may only be used and pri
21、nted by approved subscription and freemailing clients of the SABS .61094-6 IEC:2004 7 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ MEASUREMENT MICROPHONES Part 6: Electrostatic actuators for determination of frequency response FOREWORD 1) The International Electrotechnical Commission (IEC) is a world
22、wide 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 standardization in the electrical and electronic fields. To this end and in addition to other ac
23、tivities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subje
24、ct 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 the International Organization for Standardization (ISO) in accordance with conditions dete
25、rmined 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 subjects since each technical committee has representation from all interested IEC National Commi
26、ttees. 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 content of IEC Publications is accurate, IEC cannot be held responsible for the way in which
27、 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 possible in their national and regional publications. Any divergence between any IEC Publicati
28、on and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with an IEC Publication. 6) All users should ensure that
29、 they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, 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 natu
30、re whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising 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
31、 publications is indispensable for the correct application of this publication. 9) Attention is drawn 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. Internation
32、al Standard IEC 61094-6 has been prepared by IEC technical committee 29: Electroacoustics. The text of this standard is based on the following documents: FDIS Report on voting 29/562/FDIS 29/565/RVD Full information on the voting for the approval of this standard can be found in the report on voting
33、 indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. SANS 61094-6:2009This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61094-6 IEC:2004 9 IEC 61094 consists of the following parts,
34、 under the general title Measurement microphones: Part 1: Specifications for laboratory standard microphones Part 2: Primary method for pressure calibration of laboratory standard microphones by the reciprocity technique Part 3: Primary method for free-field calibration of laboratory standard microp
35、hones by the reciprocity technique Part 4: Specifications for working standard microphones Part 5: Methods for pressure calibration of working standard microphones by comparison Part 6: Electrostatic actuators for determination of frequency response The committee has decided that the contents of thi
36、s publication will remain unchanged until the maintenance result date indicated on the IEC web site under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed; withdrawn; replaced by a revised edition, or amended. SANS 61094-6:200
37、9This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .61094-6 IEC:2004 11 MEASUREMENT MICROPHONES Part 6: Electrostatic actuators for determination of frequency response 1 Scope This part of IEC 61094 gives guidelines for the design of actuators f
38、or microphones equipped with electrically conductive diaphragms; gives methods for the validation of electrostatic actuators; gives a method for determining the electrostatic actuator response of a microphone. The applications of electrostatic actuators are not fully described within this standard b
39、ut may include a technique for detecting changes in the frequency response of a microphone, a technique for determining the environmental influence on the response of a microphone, a technique for determining the free-field or pressure response of a microphone without specific acoustical test facili
40、ties, by the application of predetermined correction values specific to the microphone model and actuator used, a technique applicable at high frequencies not typically covered by calibration methods using sound excitation. 2 Normative references The following referenced documents are indispensable
41、for the application of this document. 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 laboratory standard microphones IEC 61
42、094-2, 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 61
43、094-5, Measurement microphones Part 5: Methods for pressure calibration of working standard microphones by comparison ISO/IEC GUIDE EXPRESS: 1995, Guide to the expression of uncertainty in measurement (GUM) SANS 61094-6:2009This s tandard may only be used and printed by approved subscription and fre
44、emailing clients of the SABS .61094-6 IEC:2004 13 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 61094-1 as well as the following apply. 3.1 electrostatic actuator device for determination of microphone frequency response comprising an electrically
45、conductive stiff plate placed near the microphone diaphragm such that a time-varying voltage, applied between the plate and the diaphragm, produces an electrostatic force that simulates a sound pressure uniformly distributed over the surface of the diaphragm 3.2 electrostatic actuator response of a
46、microphone microphone output as a function of frequency measured using a specified design of electro-static actuator driven by a voltage that is of uniform amplitude with frequency, relative to the output at a specified frequency NOTE Electrostatic actuator response is expressed in decibels (dB). 3.
47、3 acoustic radiation impedance acoustic impedance loading the microphone diaphragm on its outer surface NOTE 1 Acoustic radiation impedance is expressed in pascal-second per cubic meter (Pas m3).NOTE 2 The radiation impedance depends on the presence and design of the actuator. 4 Reference environmen
48、tal conditions The reference environmental conditions are: temperature 23,0 C static pressure 101,325 kPa relative humidity 50 % 5 Principle of electrostatic actuator operation 5.1 General In practice, measurements of sound are made in many different environments where different types of sound field
49、s exist. The sensitivity and frequency response of measurement microphones depend on the type of sound field, so ideally the microphone should be calibrated using a similar type of field to that which exists on the measurement site. The various types of sound fields are generally approximated by three idealized fields: free field, diffuse-field and pressure-field. However, the establishment of such idealized soun
