ISO INTERNATIONAL STANDARD 718 Second edition 1990-12-01 ANSi Internat Doc Sec Laboratory glassware Thermal shock and thermal shock endurance .-- Test methods Verrerie de laboratoire - Choc thermique et endurance au choc thermique -- Methodes d'essai Reference number ISO718:1990(E) Provided by IHS under license with ISO right International Organization for Standardizatior No reproduction or netiworking permited withou license from IHs Not for Resale ISO 718:1990(E) Foreword Iso (the Internationai Organization for Standardization) is a worldwide federation of national standards bodies (iso 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 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 all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an Inter- national Standard requires approval by at least 75% of the member bodies casting avote. International Standard Iso 718 was prepared by Technical Committee Iso/TC48,Laboratoryglasswareandrelatedapparatus. This second edition cancels and replaces the first edition (isoO 718:1982), of which it constitutes a technical revision. Annex A of this Internationai Standard is for information only. ISO1990 or by any means, electronic or mechanicat, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization CasePostale56CH-1211Geneve20·Switzerland Printed in Switzerland Provided by IHS under license with ISc ght International Organization for Standardizatior No reproduction or networking permited without license from IHS Not for Resale INTERNATIONAL STANDARD ISO 718:1990(E) Laboratory glassware --. Thermal shock and thermal shock endurance - Test methods 1 Scope water temperature to within ± 1 'c of a specified lower temperature, t2, within the range 0 °C to 27 °C. This International Standard specifies a thermal shock test and the procedure for determining the NOTE1 The total volume of the samples is taken as the thermal shock endurance for laboratory glassware sum of the volume of the individual samples when each in the condition received by the customer. is regarded as being solid. This International Standard does not apply to fused 3.2 Test oven. preferably electrically heated with a silica ware and annealed containers made from temperature range up to at least 300 oc. It shall be soda-lime-silicate glass. fitted with an air circulating device to ensure that the temperature variation does not exceed ± 5 c and Anneaied containers made from soda-lime-silicate a thermostatic control capable of maintaining the glass shall be tested according to Iso 7459. test oven temperature fluctuation within ± 1 oC up 300 °C. 2 Definitions For the purposes of this Internationat Standard, the 3.3 Tongs, with tips protected by a heat resisting following definitions apply. material such as giass or mineral wool. 2.1 thermal shock: A sudden change in temper- 3.4 Gloves, gauntet-type and preferably made ature applied to laboratory glassware. from an asbestos- substitute material. 2.2 thermal shock endurance Atso: A temperature 3.5 Basket, for testing two or more samples simul- difference interpolated by linear regression at which taneously. It shall be made out of or coated with a 50 % of the samples will probably fail. material which will not scratch or scuff the samples during the test procedure. It shali be capable of 2.3 temperature variation: The difference at any holding the samples upright and separate and of al- moment between the temperature at the c