ISO INTERNATIONAL STANDARD 2231 Second edition 1989-08-01 Rubber- or plastics-coated fabrics - Standard atmospheres for conditioning and testing Supports textiles revetus de caoutchouc ou de plastique - Atmospheres normales deconditionnementetd'essai Reference number ISO 2231 : 1989 (E) ISO 2231 : 1989 (E) Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried outthroughiSOtechnical committees.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, govern- mental and non-governmental, in liaison with ISo, also take part in the work. ISo collaborates closely with the International Electrotechnical Commission (IEC) on al matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISo Council. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 2231 was prepared by Technical Committee ISO/TC 45, Rubberand rubberproducts. This second edition cancels and replaces the first edition (ISo 2231 : 1973), clauses 3 and 4 of which have been technically revised (see clauses 5 and 6 in revised text). In ad- dition, a new clause on pre-conditioning has been introduced (clause 4 in revised text). ISO 1989 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any writing from the pubtisher. International Organization for Standardization Case postale 56 . CH-1211 Geneve 20 Switzerland Printed in Switzerland ii ISO 2231 : 1989 (E) Introduction Most coated fabrics contain a certain amount of moisture absorbed from the air with which they are in contact, and the amount of moisture depends on the quantity of water vapour in the air. of threads, are affected by the moisture content of the fabric. In order to standardize methods of test it is, therefore, important to control the moisture content of the mate- riai under test. This is done by conditioning test pieces in an atmosphere of controlled humidity before testing. For some other properties, the effect of the moisture content of the fabric is minimal, and it is only necessary to condition for temperature. ii