ISO INTERNATIONAL STANDARD 11821 First edition 1997-04-01 Acoustics Measurement of the in situ sound attenuation of a removable screen Acoustique --- Mesurage de I'attenuation acoustique in situ d'un écran amovible This material is reproduced from Iso documents under International Organization for Standardization (Iso) Copyright License number IHS/IcC/1996. Not for resale. No part of these isO documents may be reproduced in any form, electronic retrieval system or otherwise, except as allowed in the copyright law of the country of use, or with the prior written consent of Iso (Case postale 56, 1211 Geneva 20, Switzerland, Fax +41 22 734 10 79), IHs or the Iso Licensor's members. ISO Reference number ISO 11821:1997(E) Copyright International Organization for Standardization No reproduction or networking permitted without license from IHS Not for Resale ISO 11821:1997(E) Contents Page 1 Scope 1 2 Normative references 2 3 Definitions 2 4 Instrumentation 3 5 Determination of in situ sound attenuation 3 6 Uncertainty 7 7 Information to be recorded 8 8 Information to be reported 9 Annex A Bibliography 10 @ISO1997 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, withoutpermission in writing from the publisher. International Organization for Standardization Case postale 56 . CH-1211 Genéve 20 · Switzerland Internet [email protected] X.400 C=ch; a=400net; p=iso;0=isocs; s=central Printed in Switzerland Copyright international Organization for Standardization thout license from IHS Not for Resale @ISO ISO11821:1997(E) Foreword Iso (the International Organization for Standardization) is a worldwide preparing International Standards is normally carried out through isO technical committees. Each member body interested in a subject for which on that committee. International organizations, governmental and non- governmental, in liaison with IsO, also take part in the work. .ISO coltaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting avote. International Standard ISO 11821 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise. Annex A of this International Standard is for information only ili CopyrightlInternational Organization for Standardizatin ed without license from IHS Not for Resale