ISO INTERNATIONAL STANDARD 11561 First edition 1999-07-01 Ageing of thermal insulation materials - Determination of the long-term change in thermal resistance of closed-cell plastics (accelerated laboratory test methods) Vieillissement des materiaux isolants thermiques Détermination du changement a long terme de la resistance thermique des plastiques alveéolaires a cellules fermées (méthodes d'essai de laboratoire accéléreées) ISO Referencenumber ISO 11561:1998(E) y IHS under ted without license from IHS Not for Resale ISO 11561:1999(E) Contents Page 1 Scope 2 Normative reference 3Definitions 4 Test methods - General ... 5 Method A - Test to determine time-dependent change in thermal properties of core materials . 6 Method B Simplified test to determine a design life-time thermal resistance of an unfaced product ....6 7Precision 8Test repor Annex A (informative) Analytical model.. Annex B (informative) Example of the determination of long-term thermal resistance of faced products .... 15 Bibliography.. ..18 @ISO1999 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic International OrganizationforStandardization Casepostale56·CH-1211Geneve20·Switzerland Internet [email protected] Printed in Switzerland onal Organization for Standardizatior @ISO ISO 11561:1999(E) Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(lSo member bodies). The work of preparing International Standards is normally carried out through iSO technical committees. Each member body interested in a subject for which a technical committee has been established has liaison with IsO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 3. Draft International Standards adopted by technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75% of the member bodies casting a vote International Standard ISO 11561 was prepared by Technical Committee ISO/TC 163, Thermal insulation, Subcommittee SC 1, Test and measurement methods. Annexes A and B of this International Standard are for information only. ii