ISO/TS TECHNICAL SPECIFICATION 19425 First edition 2015-12-15 Reciprocating internal combustion engines Measurement method for air cleaners Sound power level of combustion air inlet noise and insertion loss using sound pressure Moteurs alternatifs a combustion interne - Methode de mesure du bruit des purificateurs d'air - Niveau de puissance sonore du bruit d'entrée d'air de combustion et de perte d'insertion utilisant une pression sonore Reference number ISO/TS 19425:2015(E) ISO International Organization for Standardization @ IS0 2015 HS unde ed without license from IHS IS0/TS 19425:2015(E) COPYRIGHT PROTECTEDDOCUMENT IS0 2015, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form 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 +41 22 749 09 47 [email protected] www.iso.org icensee-ZHEJIANG INSTOF STANDARDIZAoISQ 05 - All rights reserved Not for Resale, 2016/3/29 05:17:00 networking permited without license from IHS IS0/TS 19425:2015(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references 3 Terms and definitions 4 Test environment .5 4.1 General .5 4.2 Criterion for background noise. .5 4.3 Criterion for acoustic adequacy of test environment .6 5 Instrumentation. .6 5.1 General. .. 6 5.2 Calibration .6 5.3 Application .6 6 Installation and operation conditions 6.1 General 6.2 Installation condition 6.3 Operation condition.. ..8 7 Measurement ..8 7.1 General ..8 7.2 Measurement uncertainty ..9 7.3 Characteristic source dimension .10 7.4 Measurement radius .10 7.5 Measurement surface and area .10 7.6 Microphone arrays. 10 8 Calculation .12 8.1 General 12 8.2 Calculation of sound powerlevel .12 8.2.1 Mean time-averaged sound pressure levels .12 8.2.2 Corrections for background noise. ..13 8.2.3 Corrections for environmental .13 8.2.4 Surface time-averaged sound pressure levels ..14 8.2.5 Sound power levels. ..14 8.3 Calculation of insertion loss .14 9 Information to be recorded ..15 10 Test report. ..16 Annex A (normative) Qualification procedures for the acoustic environment 17 Annex B (normative) Calculation of A-weighted sound power levels from frequency band levels 20 Annex C (normative) Sound power level under reference meteorological conditions. .22 Bibliography ..24 ii icenSee=ZHEJIANG INST OF STANDARDIZATION C1 5956617 d without license from IHS Not for Resale, 2016/3/29 05:17:00