ISO INTERNATIONAL STANDARD 9295 Secondedition 2015-05-15 Acoustics Determination of high frequency sound power levels emitted by machinery and equipment Acoustique - Détermination des niveaux de puissance acoustique a haute frequence émis par les machines et équipements Reference number IS0 9295:2015(E) SO International Organization for Standardization @ IS0 2015 ng Institute of Standardization 5956617 ted without license from IHS IS0 9295:2015(E) COPYRIGHTPROTECTEDDOCUMENT IS02015,PublishedinSwitzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel.+41 22 749 01 11 Fax +41227490947 [email protected] www.iso.org Intenationai br PrganizationforStandardization I by IHS unde Not for Resale, 2015/8/6 09:51:18 etworking permitted without license from IHS IS0 9295:2015(E) Contents Page Foreword ..V Introduction. ...vi 1 Scope 2 Normative references 3 Terms and definitions 4 Conformity requirements .1 5 1 Requirements for measurements in a reverberation test room 5.1 General. .1 5.2 Meteorological conditions. .2 5.3 Instrumentation. .2 5.4 Installation and orientation of microphone 5.5 Installation and orientation of equipment. .3 5.6 Calibration of measurement system 3 5.7 Measurement of sound pressure level. 3 6 Method using measured reverberation time .4 6.1 General ..4 6.2 Measurement of reverberation time .5 6.3 Calculation of room absorption ..5 6.4 Installation of microphone and equipment .5 6.5 Measurement of sound pressure level .5 6.6 Calculation of sound power level .6 7 Method using calculated air absorption .6 7.1 General .6 7.2 Calculation of room constant. ..6 7.3 Installation of microphone and equipment ..6 7.4 Measurement of sound pressure level. 7.5 Calculation of sound power level. .1 Method using a reference sound source .8 8 8.1 Reference sound source. 8.2 Installation of microphone and equipment ..8 8.3 Installationofreferencesoundsource ..9 8.4 Measurementofsoundpressurelevel .9 8.5 Calculation of sound power level .9 8.5.1 Equipment emitting broad-band noise .9 8.5.2 Equipment emitting discrete tone(s) .10 9 Method using a free field over a reflecting plane ..10 9.1 ..10 General 9.2 Meteorological conditions. .10 9.3 Instrumentation ..1 9.4 Installation and orientation of microphone ..11 9.5 Installation of equipment. .11 9.6 Calibration of measurement system .11 9.7 Measurement of sound pressure level ..12 9.8 Calculation of surface sound pressure level and sound power level. ..12 10 Calculation of sound power level under reference meteorological conditions ..13 10.1 Reverberation rooms. ..13 10.2 Hemi-anechoic rooms ..13 11 Measurement uncertainty ..13 12 Information to be recorded. ..13 ntemaonalganizatin5All rights reserved iii iseeZhejang Insttute of Standardization 5956617 Provided by IHS under license with ISC ed without license from IHS Not for Resale, 2015/8/6 09:51:18