IEC_61400-11_Acoustic_noise_measurement_techniques_2002.pdf

INTERNATIONALSTANDARDIEC61400-11Second edition2002-12Wind turbine generator systems Part 11:Acoustic noise measurement techniquesArognrateurs Partie 11:Techniques de mesure du bruit acoustiqueReference numberIEC 61400-11:2002(E)Publication numberingAs from 1 January 1997 all IEC publications are issued with a designation in the60000 series.For example,IEC 34-1 is now referred to as IEC 60034-1.Consolidated editionsThe IEC is now publishing consolidated versions of its publications.For example,edition numbers 1.0,1.1 and 1.2 refer,respectively,to the base publication,thebase publication incorporating amendment 1 and the base publication incorporatingamendments 1 and 2.Further information on IEC publicationsThe technical content of IEC publications is kept under constant review by the IEC,thus ensuring that the content reflects current technology.Information relating tothis publication,including its validity,is available in the IEC Catalogue ofpublications(see below)in addition to new editions,amendments and corrigenda.Information on the subjects under consideration and work in progress undertakenby the technical committee which has prepared this publication,as well as the listof publications issued,is also available from the following:IEC Web Site(www.iec.ch)Catalogue of IEC publicationsThe on-line catalogue on the IEC web site(http:/www.iec.ch/searchpub/cur_fut.htm)enables you to search by a variety of criteria including text searches,technicalcommittees and date of publication.On-line information is also available onrecently issued publications,withdrawn and replaced publications,as well ascorrigenda.IEC Just PublishedThis summary of recently issued publications(http:/www.iec.ch/online_news/justpub/jp_entry.htm)is also available by email.Please contact the CustomerService Centre(see below)for further information.Customer Service CentreIf you have any questions regarding this publication or need further assistance,please contact the Customer Service Centre:Email:custserviec.chTel:+41 22 919 02 11Fax:+41 22 919 03 00INTERNATIONALSTANDARDIEC61400-11Second edition2002-12Wind turbine generator systems Part 11:Acoustic noise measurement techniquesArognrateurs Partie 11:Techniques de mesure du bruit acoustique IEC 2002 Copyright-all rights reservedNo part of this publication may be reproduced or utilized in any form or by any means,electronic ormechanical,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.chXFor price,see current cataloguePRICE CODECommission Electrotechnique InternationaleInternational Electrotechnical Commission 2 61400-11 IEC:2002(E)CONTENTSFOREWORD.4INTRODUCTION.51Scope.62Normative references.63Definitions.74Symbols and units.85Outline of method.96Instrumentation.106.1Acoustic instruments.106.2Non-acoustic Instruments.116.3Traceable calibration.127Measurements and measurement procedures.127.1Measurement positions.127.2Acoustic measurements.137.3Non-acoustic measurements.158Data reduction procedures.178.1Wind speed.178.2Correction for background noise.188.3Apparent sound power levels.188.4One-third octave band levels.198.5Tonality.198.6Directivity(optional).229Information to be reported.239.1Characterisation of the wind turbine.239.2Physical environment.249.3Instrumentation.249.4Acoustic data.249.5Non-acoustic data.259.6Uncertainty.25Annex A(informative)Other possible characteristics of wind turbine noise emissionand their quantification.35Annex B(informative)Criteria for recording/playback equipment.37Annex C(Informative)Assessment of turbulence intensity.39Annex D(informative)Assessment of measurement uncertainty.40Bibliography.43Figure 1 Mounting of the microphone.26Figure 2 Picture of microphone and board.27Figure 3 Standard pattern for microphone measurement positions(plan view).28Figure 4 Illustration of the definitions of R0 and slant distance R1.2961400-11 IEC:2002(E)3 Figure 5 Allowable region for meteorological mast position as a function of plan view.30Figure 6 Allowable range for anemometer height cross section.31Figure 7 Workflow chart for tonality procedure.32Figure 8 Illustration of L70%level in the critical band.33Figure 9 Illustration of lines below the L70%+6dB criterion.33Figure 10 Illustration of Lpn,avg level and lines classified as masking.34Figure 11 Illustration of classifying all spectral lines.34Figure B.1 Tolerances for frequency characteristic,IEC 60651 type 1.37Table 1 Roughness length.18Table 2 Frequency resolution.19Table D.1 Examples of possible values of type B uncertainty components relevant forapparent sound power level.41 4 61400-11 IEC:2002(E)INTERNATIONAL ELECTROTECHNICAL COMMISSION_WIND TURBINE GENERATOR SYSTEMS Part 11:Acoustic noise measurement techniquesFOREWORD1)The IEC(International Electrotechnical Commission)is a worldwide organization