ISO INTERNATIONAL STANDARD 1996-2 Third edition 2017-07 Acoustics Description, measurement and assessment of environmental noise - Part 2: Determination of sound pressure levels Acoustique - Description, évaluation et mesurage du bruit de I'environnement- Partie 2: Détermination des niveaux de pression acoustique Reference number IS0 1996-2:2017(E) os1 International Organization for Standardization @ IS0 2017 d without license from IHS IS0 1996-2:2017(E) COPYRIGHTPROTECTEDDOCUMENT IS0 2017, 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. ISOcopyrightoffice Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel.+4122 749 0111 Fax +41 22 749 09 47 copyright@iso.org www.iso.org Internatinair PrganizationforStandardization @ IS0 2017 - All rights reserved etworking permitted without license from IHS IS0 1996-2:2017(E) Contents Page Foreword ..V Introduction. ...vi 1 Scope. 2 Normative references 3 Terms and definitions 4 Measurement uncertainty ..3 5 Instrumentation for acoustical measurements .5 5.1 General .5 5.2 Calibration 5.3 Verification .6 5.4 Long-term monitoring 6 Principles 6.1 General. .6 6.2 Independent measurements 7 Operation of the source ..8 7.1 General ..8 7.2 Road traffic 7.2.1 Leqg measurement .8 7.2.2 Lmax measurement ..9 7.3 Railtraffic .9 7.3.1 Leq measurement. .9 7.3.2 Lmax measurement. .9 7.4 Airtraffic .10 7.4.1 Leg measurement. .10 7.4.2 Lmax measurement ..11 7.5 Industrial plant... ..11 7.5.1 Leq measurement ..11 7.5.2 Lmax measurement. ..11 8 Meteorological conditions .12 8.1 General. .12 8.2 Favourable propagation .13 8.3 Effects of precipitation on measurements ..13 9 Measurement procedures. .13 9.1 Selection of measurement time interval .13 9.1.1 Long-term measurements. ..13 9.1.2 Short-term measurements ..14 9.2 Microphone location .14 9.2.1 Outdoors. .14 9.2.2 Indoors ..15 9.3 Measurements .15 9.3.1 Long-term unattended measurements ..15 9.3.2 Short-term attended measurements .16 9.3.3 Residualsound ..17 9.3.4 Frequency range of measurements ..17 9.3.5 Measurements of meteorological parameters ..17 10 Evaluation of the measurement results .18 10.1 General ..18 10.2 Determination of LE,T, Leq,T and LN,T ..18 10.2.1 LE,T and Leq,T. 10.2.2 LN,T ..18 iii d without license from IHS