《BS-EN-ISO-1741-1995.pdf》由会员分享,可在线阅读,更多相关《BS-EN-ISO-1741-1995.pdf(8页珍藏版)》请在三一文库上搜索。
1、BRITISH STANDARD BS EN ISO 1741:1995 Dextrose Determination of loss in mass on drying Vacuum oven method The European Standard EN ISO 1741:1994 has the status of a British Standard UDC 664.162:543.81 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 13:56:24 GMT+00:00 2006, Uncontrolled Copy, (
2、c) BSI BS EN ISO 1741:1995 This British Standard, was published under the authority of the Standards Board and comes into effect on 15 January 1995 BSI 01-2000 The following BSI reference relate to the work on this standard: Draft announced in BSI News, March 1993 ISBN 0 580 23176 3 Cooperating orga
3、nizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: AustriaOesterreichisches Normungsinstitut BelgiumInstitut belge de normalisation DenmarkDansk Standard F
4、inlandSuomen Standardisoimisliito, r.y. FranceAssociation franaise de normalisation GermanyDeutsches Institut fr Normung e.V. GreeceHellenic Organization for Standardization IcelandTechnological Institute of Iceland IrelandNational Standards Authority of Ireland ItalyEnte Nazionale Italiano di Unifi
5、cazione LuxembourgInspection du Travail et des Mines NetherlandsNederlands Normalisatie-instituut NorwayNorges Standardiseringsforbund PortugalInstituto Portugus da Qualidade SpainAsociacin Espaola de Normalizacin y Certificacin SwedenStandardiseringskommissionen i Sverige SwitzerlandAssociation sui
6、sse de normalisation United KingdomBritish Standards Institution Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 13:56:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 1741:1995 BSI 01-2000i Contents Page Cooperating organization
7、sInside front cover National forewordii Foreword2 1Scope and field of application3 2Principle3 3Apparatus3 4Procedure3 5Expression of results3 6Test report3 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 13:56:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 1741:1995 ii BSI 01-2000 N
8、ational foreword This British Standard has been prepared under the direction of the BSI Standards Board and is the English language version of EN ISO 1741:1994 Dextrose Determination of loss in mass on drying Vacuum oven method, published by the European Committee for Standardization (CEN). It is id
9、entical with ISO 1741:1980 Dextrose Determination of loss in mass on drying Vaccum oven method, published by the International Organization for Standardization (ISO). This British Standard has been produced to fulfil BSIs obligation to publish all approved European Standards but, because of the abse
10、nce of interest in the UK in the subject concerned, there has been no UK participation in the preparation of EN ISO 1741. Any queries relating to the EN should be directed to BSI. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards ar
11、e responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN ISO title page, pages 2 and 3 and a back cover. This standa
12、rd has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 13:56:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUR
13、OPISCHE NORM EN ISO 1741 August 1994 UDC 664.162:543.81 Descriptors: Carbohydrates, glucose, tests, determination, mass losses, dehydration analysis, stoves (chemistry), low pressure tests English version Dextrose Determination of loss in mass on drying Vacuum oven method (ISO 1741:1980) Dextrose cr
14、istallis Dtermination de la perte de masse la dessiccation Mthode par tuvage sous pression rduite (ISO 1741:1980) Dextrose Bestimmung des Masseverlustes durch Trocknen Vakuumschrank-Verfahren (ISO 1741:1980) This European Standard was approved by CEN on 1994-08-22. CEN members are bound to comply wi
15、th the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretar
16、iat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
17、 versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Norm
18、alisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1994 Copyright reserved to CEN members Ref. No. EN ISO 1741:1994 E Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 13:56:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 1741:1994 BSI 01-2000
19、 2 Foreword The text of the International Standard ISO 1741:1980, prepared by ISO/TC 93, Starch, was submitted to the formal vote and was approved by CEN as EN ISO 1741:1994 on 1994-08-22 without any modifications. This European Standard shall be given the status of a national standard, either by pu
20、blication of and identical text or by endorsement, at the latest by February 1995, and conflicting national standards shall be withdrawn at the latest by February 1995. According to the CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria,
21、Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 13:56:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 1741:1994 BSI 01-20003
22、 1 Scope and field of application This International Standard specifies a vacuum oven method for the determination of the loss in mass on drying of dextrose. The method is applicable to anhydrous dextrose and to dextrose monohydrate. 2 Principle Drying of the test portion in a vacuum oven at 100 C,
23、at a pressure not exceeding 135 mbar1). 3 Apparatus 3.1 Analytical balance 3.2 Dish, of metal (inert under the test conditions) or of glass, of diameter approximately 50 mm, provided with a closely fitting lid. 3.3 Electrically heated vacuum oven, capable of being maintained at 100 1 C, equipped wit
24、h a calibrated thermometer and an absolute pressure gauge. The drying oven shall provide uniform heat distribution and shall maintain the reduced pressure for several hours after the vacuum pump is turned off. The oven shelves shall be so constructed and fitted as to ensure good heat transfer to the
25、 dishes. 3.4 Vacuum pump, suitable for reducing the pressure in the oven to 135 mbar or less. 3.5 Drying train, consisting of a drying column filled with dried silica gel; the column is connected in series to a gas scrubber containing concentrated sulphuric acid, which is in turn connected to the ai
26、r inlet of the drying oven. 3.6 Desiccator, containing an efficient desiccant. 4 Procedure 4.1 Preparation of the test sample Mix the sample thoroughly and rapidly by stirring with a spatula in the sample container. If the sample container is too small for this purpose, transfer the entire sample to
27、 another pre-dried container of a suitable size to facilitate mixing. 4.2 Preparation of the dish Place the open dish (3.2) and its lid in the oven (3.3), controlled at 100 C for 1 h. Allow to cool to room temperature in the desiccator (3.6) and weigh to the nearest 0,000 2 g. 4.3 Test portion Place
28、 about 10 g of anhydrous dextrose or about 5 g of dextrose monohydrate, in the dish (3.2), fit the lid and weigh to the nearest 0,000 2 g. 4.4 Determination Place the covered dish (3.2) containing the test portion (4.3) in the oven (3.3) maintained at 100 1 C, remove the lid and leave it in the oven
29、. Leave at the test temperature for 4 h, maintaining the pressure in the oven at not more than 135 mbar. During drying, draw a slow stream of air through the drying train (3.5) into the oven. After 4 h, shut off the vacuum pump (3.4) and allow air to slowly enter the oven through the drying train un
30、til atmospheric pressure is obtained. Before withdrawing the dish from the oven, fit the cover. Place the covered dish in the desiccator (3.6), allow to cool to room temperature, and weigh to the nearest 0,000 2 g. Do not put more than four dishes in the desiccator (3.6) at the same time. Carry out
31、two determinations on the same test sample (4.1). NOTEIf, during or after the test, the material develops a more or less pronounced yellow colour, repeat the test at a lower temperature, and state this in the test report. 5 Expression of results The loss in mass on drying, expressed as a percentage
32、by mass of the product as received, is equal to where m0is the mass, in grams, of the dish and cover (4.2); m1is the mass, in grams, of the dish and cover and the test portion before drying (4.3); m2is the mass, in grams, of the dish and cover and the test portion after drying (4.4). Take as the res
33、ult the arithmetic mean of the two determinations. 6 Test report The test report shall indicate the method used and the result obtained. It shall also mention all operating conditions not specified in this International Standard, or regarded as optional, as well as any circumstances that may have in
34、fluenced the result. The report shall include all details required for complete identification of the sample. 1) 1 mbar = 0,1 kPa m1 m2() 100 m1 m0 - Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 13:56:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 1741:1995 BSI 389 Chiswick High R
35、oad London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by amendme
36、nt or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard woul
37、d inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: 020 8996 9000. Fax: 020 8996 7400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions
38、of standards. Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel: 020 8996 9001. Fax: 020 8996 7001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that hav
39、e been published as British Standards, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Various BSI electronic information services are also
40、 available which give details on all its products and services. Contact the Information Centre. Tel: 020 8996 7111. Fax: 020 8996 7048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For details of thes
41、e and other benefits contact Membership Administration. Tel: 020 8996 7002. Fax: 020 8996 7001. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the international standardization bodies. Except as permitted under the Copyright, Des
42、igns and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without prior written permission from BSI. This does not preclude the free use, in the course of implementing the standard,
43、 of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel: 020 8996 7070. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 13:56:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI
链接地址:https://www.31doc.com/p-3745027.html