TSO NTERNATIONAL STANDARD 1392 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEXKIYHAPOIHA OPTAHM3ALINS HO CTAHAPTW3ALIWM·ORGANISATION INTERNATIONALE DE NORMALISATION Determination of crystallizing point - General method Determination du point de cristallisation -Methode generale First edition - 1977-02-15 FE8 2 3 1917 ANsi Internat Doc Sect ISO 1392-1977 (E) UDC 536.421.4 Ref. No. 1SO 1392-1977 (E) Descriptors: chemical tests, measurement, solidification point. Price based on 4 pages FOREWORD ISo (the International Organization for Standardization) is a worldwide federation of national standards institutes (IsO member bodies). The work of developing International Standards is carried out through IsO technical committees.Every member body interested in a subject for which a technical committee has been set up 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. 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. Prior to 1972, the results of the work of the technical committees were published as Iso Recommendations; these documents are in the process of being transformed into International Standards. As part of this process, Technicai Committee ISO/TC47, Chemistry, has reviewed ISO Recommendation R 1392-1970 and found it technicaliy suitable for transformation. International Standard IsO 1392 therefore replaces is0 Recommendation R 1392-1970, to which it is technically identical. ISO Recommendation R 1392 had been approved by the member bodies of thefollowingcountries : Austria India Romania Belgium Iran South Africa, Rep. of Chile Israel Spain Czechoslovakia Italy Switzerland Egypt, Arab Rep. of Netherlands Thailand France New Zealand Turkey Germany Peru United Kingdom Hungary Portugal U.S.S.R. Nomember body had expressed disapproval of the Recommendation. No member body disapproved the transformation of the Recommendation into an internationai Standard. @ International Organization for Standardization, 1977: Printed in Switzerland INTERNATIONAL STANDARD ISO 1392-1977 (E) Determination of crystallizing point - General method 1 SCOPEANDFIELDOFAPPLICATION 4.4 Precision thermometer graduated at intervals of 0,1 °c, with a known maximum scale error of 0,1 °c, and with the This International Standard specifies a general method for the determination of crystallizing points in the range from range stated in the specific test method for the particular material. about-50toabout+250C. The crystallizing point can be determined directly on the 4.5 Dewar vessel of approximately 500 ml capacity. sample as received, or on the dried sample, or on both. In containing theappropriate cooling mixture (carbon which of these conditions the sample is to be tested and, if dioxide/acetone or ice/water or water) and provided with the determination is to be made with the dried sample, a suitable laboratory thermometer. An example of such a what method of drying is to be used, will be stated in the Dewar vessel is given in figure 2, but other vessels of the specific test method for each material. same capacity may also be used. 4.6 Dewar vessel, as shown in figure 3. (it is not necessary 2 PRINCIPLE for the inner surfaces of the vessel to be silvered.) Cooling the liquid or liquefied sample, and determination of the crystallizing point by observation of the temperature 4.7 Heating bath, as shown in figure 4, containing silicone during crystallization under defined conditions. oil or other suitable liquid heating medium, and provided with a suitable laboratory thermometer. 3 REAGENTS 5PROCEDURE 3.1 Acetone. 5.1 Preparation of the sample for the direct determination 3.2 Solid carbon dioxide. of the crystallizing point on the sample as received 3.3 1ce. 5.1.1 Liquid products Fill the crystallizing tube (4.1) to a d