ISO INTERNATIONAL STANDARD 2578 Second edition 1993-08-01 Plastics Determination of time-temperature limits after prolonged exposure to heat Plastiques Détermination des limites temps-temperatures apres expositiona I'action prolongée de la chaleur Reference number ISO 2578:1993(E) No reproductic Not fe ISO 2578:1993(E) Contents Page 1 Scope 1 2 Normative references 3 Definitions 2 4 Principle 2 5 Choice of test 6 Choice of end-point 3 7 Test specimens 3 8 Exposure temperatures 3 9 Ageing ovens 10 Procedure 11 Evaluation of results 4 12 Determination of the relative temperature index 13 Test report Annexes A Calculation of the regression line 9 B Correlation coefficient 13 c Recommended test schedule for primary properties 14 ISO1993 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without per- mission in writing from the publisher International Organization for Standardization Case Postale 56 . CH-1211 Genéve 20 · Switzerland Printed in Switzerland ii Copyright International Organization for Standardizatior se from IHS ISO 2578:1993(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies (lsO member bodies). The work of preparing International Standards is normally carried out through IsO technical committees. E Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with isO, also take part in the work. isO collaborates closely with the International Electrotechnical Commission (lEC)onallmattersof electrotechnicalstandardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International a vote. International Standard ISO 2578 was prepared by Technical ( Committee ISO/TC 61, Plastics, Sub-Committee SC 6, Ageing, chemical and environ- mentalresistance. This second editioncancels and replaces the first edition (IsO 2578:1974), of which it constitutes a technical revision. Annexes A and B form an integral part of this International Standard. An- nex C is for information only. ili Copyright Intermational Organization for Standardization Not for Resale