ISO INTERNATIONAL STANDARD 27327-2 First edition 2014-02-15 Fans Air curtain units - Part 2: Laboratory methods of testing for sound power Ventilateurs - Rideaux d'air - Partie 2: Méthodes d'essai en laboratoire des niveaux de puissance acoustique Reference number ISO 27327-2:2014(E) LSO IS02014 IHS under ted without license from IHS Not for Resale IS0 27327-2:2014(E) COPYRIGHTPROTECTEDDOCUMENT ISO2014 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 Case postale 56:CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland @ IS0 2014 - All rights reserved No reproductic networking permited without license from IHS Not for Resale IS0 27327-2:2014(E) Contents Page Foreword ..V Introduction.. ...vi 1 Scope. 2 Normative references 3 Terms, definitions, symbols and units ..2 3.1 Terms and definitions. .2 3.2 Air curtain unit sound power levels 3.3 Other symbols. .3 4 Limitations on use. .4 4.1 General. ..4 4.2 Noise source .5 4.3 Character of noise. 4.4 Uncertainty. .5 4.5 Quantities to be measured 5 Measurement uncertainty .5 6 Instrumentation. .7 6.1 General. 6.2 Frequency analyser.. ..7 6.3 Turbulence screens and windshields .7 6.4 Reference sound source (RsS) .8 7 Test procedure. .8 7.1 Comparison method 7.2 Direct method .8 8 Acoustic environment .8 8.1 Test environment 8.2 Reverberant room .8 9 Air curtain unit installation conditions .9 10 Air curtain unit operating conditions ..9 10.1 General .9 10.2 Measurement of ambient conditions .9 10.3 Air curtain unit rotational speed ..9 10.4 Determination of air curtain unit aerodynamic operating point .9 10.5 Control of air curtain unit operating condition 11 Test setup 11.1 Setup categories. 9 11.2 Sound pressure levels .14 11.3 Aerodynamic performance .15 11.4 Test conditions. .15 11.5 Mounting methods. ..15 11.6 Microphone travel or positions ..15 12 Information to be recorded ..16 12.1 General. ..16 12.2 Air curtain unit under test .17 12.3 Acoustic environment ..17 12.4 Acoustical data appropriate to the method of test .18 13 Calculations and evaluations. .19 13.1 Calculation of one-third octave band levels ..19 13.2 Calculation of overall sound power levels ..19 13.3 Calculation of A-weighted sound power level .19 iii ed without license from IHS Not for Resale