ISO-1392-1977.pdf
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1、INTERNATIONAL STANDARD 1392 INTERNATIONAL ORGANIZATION FOR STANDARDlZATlON .MEXjWHAPOHAII OPrAHHJAUHR n0 CTAHLIAPTK3AUMH.ORGANISATION INTERNATIONALE DE NORMALISATION Determination of crystallizing point - General method De termination du point de cristallisation - Me thode gn Ez Descriptors : chemic
2、al tests, measurement, solidification point. m Ref. No. IS0 1392-1977 (E) 0 s!? Price based on 4 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 01:36:23 MDTNo reproduction
3、 or networking permitted without license from IHS -,-,- FOREWORD IS0 (the International Organization for Standardization) is a worldwide federation of national standards institutes (IS0 member bodies). The work of developing International Standards is carried out through IS0 technical committees. Ev
4、ery 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 tec
5、hnical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. Prior to 1972, the results of the work of the technical committees were published as IS0 Recommendations; these documents are in the process of being transformed
6、into International Standards. As part of this process, Technical Committee ISO/TC47, Chemistry, has reviewed IS0 Recommendation R 1392-1970 and found it technically suitable for transformation. International Standard IS0 1392 therefore replaces IS0 Recommendation R 1392-1970, to which it is technica
7、lly identical. IS0 Recommendation R 1392 had been approved by the member bodies of the following countries : Austria Belgium Chile Czechoslovakia Egypt, Arab Rep. of France Germany Hungary India Iran Israel Italy Netherlands New Zealand Peru Portugal Romania South Africa, Rep. of Spain Switzerland T
8、hailand Turkey United Kingdom U.S.S.R. No member body had expressed disapproval of the Recommendation. No member body disapproved the transformation of the Recommendation into an International Standard. 0 International Organization for Standardization, 1977 0 Printed in Switzerland Copyright Interna
9、tional Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 01:36:23 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD IS0 1392-1977 (E) Determination of crysta
10、llizing point - General method 1 SCOPE AND FIELD OF APPLICATION This International Standard specifies a general method for the determination of crystallizing points in the range from about - 50 to about + 250 C. The crystallizing point can be determined directly on the sample as received, or on the
11、dried sample, or on both. In which of these conditions the sample is to be tested and, if the determination is to be made with the dried sample, what method of drying is to be used, will be stated in the specific test method for each material. 2 PRINCIPLE Cooling the liquid or liquefied sample, and
12、determination of the crystallizing point by observation of the temperature during crystallization under defined conditions. 3 REAGENTS 3.1 Acetone. 3.2 Solid carbon dioxide. 3.3 Ice. 3.4 Calcium sulphate, dried at about 170 “C. Dry calcium sulphate dihydrate (CaS0,.2H20) for 24 h at about 170 C, all
13、ow to cool in a desiccator and then store it in an airtight container. 4 APPARATUS Ordinary laboratory apparatus and the apparatus shown in figures 1, 2, 3 and 4 comprising the following items : 4.1 Crystallizing tube, external diameter approximately 25 mm and length approximately 150 mm. 4.2 Outer
14、protection tube, internal diameter approxi- mately 28 mm, length approximately 120 mm and wall thickness approximately 2 mm. 4.3 Stirrer, of glass or stainless steel, with a loop approxi- mately 20 mm in diameter; it may be operated by hand or mechanically, to provide approximately one 30 mm stroke
15、per second. 4.4 Precision thermometer graduated at intervals of 0,l C, with a known maximum scale error of 0,l C, and with the range stated in the specific test method for the particular material. 4.5 Dewar vessel of approximately 500 ml capacity, containing the appropriate cooling mixture (carbon d
16、ioxide/acetone or ice/water or water) and provided with a suitable laboratory thermometer. An example of such a Dewar vessel is given in figure 2, but other vessels of the same capacity may also be used. 4.6 Dewar vessel, as shown in figure 3. (It is not necessary for the inner surfaces of the vesse
17、l to be silvered.) 4.7 Heating bath, as shown in figure 4, containing silicone oil or other suitable liquid heating medium, and provided with a suitable laboratory thermometer. 5 PROCEDURE 5.1 Preparation of the sample for the direct determination of the crystallizing point on the sample as received
18、 5.1 .I Liquid products Fill the crystallizing tube (4.1) to a depth of approximately 60 mm with the untreated sample and proceed as specified in 5.3. 5.1.2 Solid products Before the determination of the crystallizing point of these products, they shall be melted in a water bath, drying oven or oil
19、bath this can be carried out in the crystallizing tube (4.11, using the heating bath (4.7), care being taken to ensure that the temperature of the molten product does not exceed its melting point by more than a few degrees. Fill the crystallizing tube to a depth of approximately 60 mm with the molte
20、n sample and proceed as specified in 5.3. 5.2 Preparation of the sample for the determination of the crystallizing point on the dried sample 5.2.1 Liquid products Liquid products of normal water content i.e. less than or equal to 2 % (m/m) shall be dried in the crystallizing tube (4.1) by addition o
21、f calcium sulphate. Fill the crystallizing 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/28/2007 01:36:23 MDTNo reproduction or networking permitted without license from IHS -,-,- IS
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- ISO 1392 1977
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