EN 62585-2012 en Electroacoustics - Methods to determine corrections to obtain the free-field response of a sound level meter.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationElectroacoustics Methods to determine corrections to obtain the free-field response of a sound level meterBS EN 62585:2012National forewordThis British Standard is the UK impleme

2、ntation of EN 62585:2012. It isidentical to IEC 62585:2012.The UK participation in its preparation was entrusted to Technical 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 incl

3、ude all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2012Published by BSI Standards Limited 2012 ISBN 978 0 580 65656 9 ICS 17.140.50Compliance with a British Standard cannot confer immunity from legal obligations.This B

4、ritish Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2012.Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 62585:2012EUROPEAN STANDARD EN 62585 NORME EUROPENNE EUROPISCHE NORM October 2012 CENELEC European

5、Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung 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

6、 members. Ref. No. EN 62585:2012 E ICS 17.140.50 English version Electroacoustics - Methods to determine corrections to obtain the free-field response of a sound level meter (IEC 62585:2012) lectroacoustique - Mthode de dtermination de corrections pour obtenir la rponse en champ libre dun sonomtre (

7、CEI 62585:2012) Elektroakustik - Verfahren zur Ermittlung von Korrekturwerten fr die Bestimmung des Freifeld-Frequenzgangs eines Schallpegelmessers (IEC 62585:2012) This European Standard was approved by CENELEC on 2012-08-29. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulat

8、ions 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 application to the CEN-CENELEC Management Centre or to any CENELEC mem

9、ber. 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-CENELEC Management Centre has the same status as the official versio

10、ns. 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, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the

11、Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 62585:2012EN 62585:2012 - 2 - Foreword The text of document 29/770/FDIS, future edition 1 of IEC 62585, prepared by IEC/TC 29 “Electroacoustics“ was submitted to the I

12、EC-CENELEC parallel vote and approved by CENELEC as EN 62585:2012. The following dates are fixed: latest date by which the document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2013-05-29 latest date by which the national standards

13、conflicting with the document have to be withdrawn (dow) 2015-08-29 Attention is drawn to the possibility that 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

14、 The text of the International Standard IEC 62585:2012 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 61094-8 NOTE Harmonised as EN 61094-8. IEC 61260 NOTE Harmo

15、nised as EN 61260. IEC 61094-2 NOTE Harmonised as EN 61094-2. IEC 61094-3 NOTE Harmonised as EN 61094-3. BS EN 62585:2012- 3 - EN 62585:2012 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following documents, in whole or in

16、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) applies. NOTE When an international publication has been

17、 modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60942 - Electroacoustics - Sound calibrators EN 60942 - IEC 61094-1 - Measurement microphones - Part 1: Specifications for laboratory standard microphones EN 61094-1 - IEC 61094-5

18、 - Measurement microphones - Part 5: Methods for pressure calibration of working standard microphones by comparison EN 61094-5 - IEC 61094-6 - Measurement microphones - Part 6: Electrostatic actuators for determination of frequency response EN 61094-6 - IEC/TS 61094-7 - Measurement microphones - Par

19、t 7: Values for the difference between free-field and pressure sensitivity levels of laboratory standard microphones - - IEC 61183 - Electroacoustics - Random-incidence and diffuse-field calibration of sound level meters EN 61183 - IEC 61672-1 - Electroacoustics - Sound level meters - Part 1: Specif

20、ications EN 61672-1 - IEC 61672-2 - Electroacoustics - Sound level meters - Part 2: Pattern evaluation tests EN 61672-2 - IEC 61672-3 - Electroacoustics - Sound level meters - Part 3: Periodic tests EN 61672-3 - ISO/IEC Guide 98-3 - Uncertainty of measurement - Part 3: Guide to the expression of unc

21、ertainty in measurement (GUM) - - ISO/IEC Guide 99 - International vocabulary of metrology - Basic and general concepts and associated terms (VIM) - - BS EN 62585:2012 2 62585 IEC:2012 CONTENTS INTRODUCTION . 6 1 Scope . 7 2 Normative references . 8 3 Terms and definitions . 8 4 Reference environmen

22、tal conditions . 9 5 Uncertainties of measurement 9 6 General requirements for measurement of adjustment value and corrections 10 7 Submission and inspection . 12 8 Determination of the adjustment value at the calibration check frequency . 12 9 Determination of corrections for the typical effects of

23、 reflections from the case of the sound level meter and diffraction of sound around the microphone . 13 10 Determination of corrections for the deviation of the microphone free-field frequency response from a uniform frequency response . 13 11 Determination of corrections for the use of windscreens

24、and similar accessories 14 12 Determination of corrections over a range of frequencies when a sound calibrator is recommended for use by the sound level meter manufacturer . 14 13 Determination of corrections over a range of frequencies when a comparison coupler is recommended for use by the sound l

25、evel meter manufacturer 15 14 Determination of corrections over a range of frequencies when an electrostatic actuator is recommended for use by the sound level meter manufacturer . 16 15 Documentation . 16 Annex A (normative) Calibration check frequency Determination of the adjustment value 18 Annex

26、 B (normative) Determination of the effects of reflections from the case of the sound level meter and diffraction of sound around the microphone . 20 Annex C (normative) Determination of the effects of the use of windscreens and similar accessories . 21 Annex D (informative) Determination of correct

27、ions for use with sound calibrators to determine equivalent free-field response at all frequencies of interest 22 Annex E (informative) Determination of corrections for use with comparison couplers to determine equivalent free-field frequency response at all frequencies of interest 25 Annex F (infor

28、mative) Determination of corrections for use with electrostatic actuators to determine equivalent free-field frequency response at all frequencies of interest 28 Annex G (informative) Comparison techniques. 31 Annex H (informative) Exact one-twelfth-octave frequencies 34 Annex I (informative) Exampl

29、e calculations of expanded uncertainty of measurement 36 Bibliography 40 Figure 1 Mounting methods for the sound level meter 11 Figure A.1 Diagrammatic representation of factors for consideration in optimising adjustment value at the calibration check frequency . 19 Figure D.1 Measurement steps usin

30、g a sound calibrator 22 Figure E.1 Measurement steps using a comparison coupler . 25 BS EN 62585:201262585 IEC:2012 3 Figure F.1 Measurement steps using an electrostatic actuator . 28 Table H.1 Exact frequencies for one-twelfth-octave steps over one decade . 35 Table I.1 Description of likely uncert

31、ainty components . 37 Table I.2 Uncertainty example for a frequency of 1 kHz . 38 Table I.3 Uncertainty example for a frequency of 8 kHz . 39 BS EN 62585:2012 6 62585 IEC:2012 INTRODUCTION The performance specification International Standard for sound level meters, IEC 61672-1, requires that at leas

32、t one model of sound calibrator, conforming to the requirements of IEC 60942 be specified in the instruction manual for checking and maintaining the correct indication on the display of the sound level meter at the calibration check frequency. The sound level meter manufacturer specifies the adjustm

33、ent value to be applied to obtain the required indication on the display in response to the sound pressure level generated by the sound calibrator, in order to optimize performance over the complete frequency range. In addition, various corrections need to be available over a range of frequencies in

34、 order for a periodic test of a sound level meter to be performed according to IEC 61672-3. For example, corrections are needed for any effects of the sound level meter case or of accessories such as windscreens on the equivalent free-field sound level. Information on these corrections is also requi

35、red by users of sound level meters and sound calibrators on a regular basis. Also, a manufacturer producing a sound level meter to the specifications of IEC 61672-1, may recommend, in the instruction manual, the use of a sound calibrator, comparison coupler or electrostatic actuator to determine the

36、 acoustical response of a sound level meter at various frequencies. In this case the manufacturer is required to provide corrections to obtain equivalent sound levels that would be displayed under reference environmental conditions in response to plane progressive sinusoidal waves that are incident

37、from the reference direction at each frequency used for periodic testing. These corrections will either be given in the instruction manual, or the instruction manual will state where they can be found. BS EN 62585:201262585 IEC:2012 7 ELECTROACOUSTICS METHODS TO DETERMINE CORRECTIONS TO OBTAIN THE F

38、REE-FIELD RESPONSE OF A SOUND LEVEL METER 1 Scope This International Standard provides information on the corrections required over a range of frequencies in order for a periodic test of a sound level meter to be performed according to IEC 61672-3. These corrections include: corrections for the typi

39、cal effects of reflections from the case of the sound level meter and diffraction of sound around the microphone; corrections for the deviation of the typical microphone frequency response from a uniform frequency response, where the actual microphone response cannot be measured; corrections for the

40、 influence on the frequency response of a typical microphone of a specified windscreen and any other accessory that is part of the configuration for normal use of the particular sound level meter submitted for testing. This International Standard includes discussion about uncertainties of measuremen

41、t of the required corrections. In some instances a maximum permitted expanded uncertainty for the manufacturer or testing laboratory is given. This maximum permitted expanded uncertainty excludes any component due to the variability of different samples of artefact (for example, microphone or windsc

42、reen). It should be noted that if large uncertainties of measurement are quoted for each of the individual corrections, when they are combined to account for the configuration of sound level meter under test, the large individual uncertainties may result in a failure to conform to the maximum permit

43、ted expanded uncertainties of measurement given in Table A.1 of IEC 61672-1:1and hence a failure of the sound level meter to conform to IEC 61672-1 In addition, this International Standard describes methods for determining these corrections, over the frequency range of interest, and explains the adj

44、ustment value at the calibration check frequency to be quoted by the manufacturer of the sound level meter (also required by IEC 61672-3). When the sound level meter manufacturer recommends the use of a sound calibrator, comparison coupler, or an electrostatic actuator for periodic testing of the ac

45、oustical response of a sound level meter at various frequencies, this International Standard describes methods of measurement of the corrections required to adjust the indication on the sound level meter to an equivalent free-field level, over the frequency range of interest. These corrections relat

46、e to a specific model of sound calibrator, comparison coupler or electrostatic actuator, microphone and sound level meter (also required by IEC 61672-3). The aim of this International Standard is to ensure that the adjustment value at the calibration check frequency and all corrections are determine

47、d using consistent and appropriate methods. It is intended that this International Standard will be used by manufacturers to determine adjustment values and corrections, by laboratories performing pattern evaluation tests according to IEC 61672-2, and by laboratories performing periodic tests accord

48、ing to IEC 61672-3. Laboratories performing periodic tests according to IEC 61672-3 will also need to consult this International Standard to ensure that the expanded uncertainties of _ 1Second edition to be published. (A revision of 61672-1:2002.) BS EN 62585:2012 8 62585 IEC:2012 measurement for th

49、e corrections quoted by the manufacturer do not exceed the maximum permitted values. The corrections obtained by use of the methods given in this International Standard are the result of measurements made using samples of the devices. It is possible that these corrections may not be totally representative either for all batches produced or over time. Repeating the measurements at regular intervals is recommended to ensure that no changes are required to the corrections stated in the in