ISO INTERNATIONAL STANDARD 2747 Second edition 1998-03-15 Vitreous and porcelain enamels - Enamelled cooking utensils - Determination of resistance to thermal shock Emaux vitrifiés - Ustensiles de cuisson émailles - Détermination de la resistanceauxchocsthermiques ISO Reference number ISO 2747:1998(E) No r py IHS under Not for Resale ISO 2747:1998(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 atechnicalcommitteehasbeenestablishedhastherighttoberepresented 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 (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the 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 2747 was prepared by Technical Committee ISO/TC 107, Metallic and other inorganic coatings, Subcommittee SC 6, Vitreous and porcelain enamels. whichhasbeentechnicallyrevised Annex A of this International Standard is for information only. @ISO1998 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced microfilm, without permission in writing from the publisher. InternationalOrganizationforStandardization Case postale 56 · CH-1211 Geneve 20 · Switzerland Internet [email protected] X.400 C=ch; a=400net; p=iso; o=isocs; S=central Printed in Switzerland license from IHS Not for Resale ISO 2747:1998(E) INTERNATIONAL STANDARD @ ISO Vitreous and porcelain enamels Enamelled cooking utensils - Determination of resistance to thermal shock Scope This International Standard specifies a method of determining, by successive thermal shock tests, the behaviour of vitreous and porcelain enamelled cooking utensils and similar articles under sudden changes of temperature (resistance to thermal shock). 2 Definitions For the purposes of this International Standard, the following definitions apply. 2.1 thermal shock test: Series of operations commencing with the pouring of cold water into the heated test specimen and ending when the thermal shock temperature for the subsequent thermal shock test has been reached. 2.2 thermal shock temperature: Temperature to which the test specimen is heated before being chilled with cold water. 2.3 thermal shock resistance: Difference between the thermal shock temperature and the water temperature at which the test specimen shows the first damage on chilling or during subsequent heating. 2.4 damage: Chipping or tension cracks in the enamel visible at a distance of 250 mm by normal 3 Principle A series of single thermal shock tests is conducted with a temperature increase of 2o c between each thermal shock obtained by heating the test specimen from the outside and then chilling it inside with water at 20 °C. For the first test, the thermal shock temperature amounts to 2oo 'C. The test ends when the first visible damage occurs. Copyright International Organization for Standardization Not for Resale