BS-EN-20638-1993 ISO-638-1978.pdf

BRITISH STANDARD BS EN 20638:1994 ISO 638:1978 Incorporating Amendment No. 1 Method for Determination of dry-matter content of pulps The European Standard EN 20638:1993 has the status of a British Standard UDC 676.16:620.1:543.814 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:24:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 20638:1994 This British Standard, having been prepared under the direction of the Paper Standards Committee, was published under the authority of the Executive Board and comes into effect on 29 February 1980 © BSI 12-1999 First published October 1969 First revision February 1980 The following BSI references relate to the work on this standard: Committee reference PAS/11 Draft for comment 77/64189 DC ISBN 0 580 11202 0 Cooperating organizations The Paper Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following Government department and professional and industrial organizations: British Paper and Board Industry Federation (PIF)* British Printing Industries Federation* Envelope Makers and Manufacturing Stationers Association* Her Majestys Stationery Office* Institute of Trading Standards Administration National Association of Paper Merchants Pira (The Research Association for the Paper and Board, Printing and Packaging Industries)* Royal Institute of Public Health and Hygiene The organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: British Wood Pulp Association Chemical Industries Association Fibreboard Packing Case Manufacturers Association Man-made Fibres Producers Committee Ministry of Defence Post Office Society of British Printing Ink Manufacturers University of Manchester, Institute of Science and Technology Amendments issued since publication Amd. No.Date of issueComments 7807February 1994Indicated by a sideline in the margin Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:24:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 20638:1994 © BSI 12-1999i Contents Page Cooperating organizationsInside front cover National forewordii Foreword2 Text of EN 206383 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:24:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 20638:1994 ii © BSI 12-1999 National foreword This British Standard has been prepared under the direction of the Paper Standards Committee. It is identical with ISO 638 “Pulps Determination of dry matter content”, which was developed by Technical Committee ISO/TC 6, Paper, board and pulps, and was published by the International Organization for Standardization (ISO). This International Standard cancels and replaces ISO Recommendation R 638:1967, of which it constitutes a technical revision. BS 4502 was first published in 1969 and was technically identical with ISO Recommendation R 638:1967. The present version has been revised and the changes include alteration of the temperature, of the oven used for drying pulp, from 103 ± 2 °C to 105 ± 2 °C. In addition, a revised method of reporting test results is included. This present edition supersedes the edition published in 1969, which is therefore withdrawn from publication. In 1993 the European Committee for Standardization (CEN) accepted ISO 638:1988 as European Standard EN 20638:1993. As a consequence of implementing the European Standard this British Standard is renumbered as BS EN 20638:1994 and any reference to BS 4502 should be read as a reference to BS EN 20638. Terminology and conventions. The text of the International Standard has been approved as suitable for publication, without deviation, as a British Standard. Some terminology and certain conventions are not identical with those used in British Standards; attention is especially drawn to the following. Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. The comma has been used throughout as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are 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 title page, pages 2 and 3 and a back cover. This standard 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, Fri Nov 03 09:24:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 20638 September 1993 UDC 676.16:620.1:543.814 Descriptors: Paper, paper pulps, cellulosic pulps, chemical analysis, determination of content, dry matter, dehydration method English version Pulps Determination of dry matter content (ISO 638:1978) Pâtes Détermination de la teneur en matières sèches (ISO 638:1978) Zellstoffe Bestimmung des Trockengehaltes (ISO 638:1978) This European Standard was approved by CEN on 1993-09-06. CEN members are bound to comply with 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 Secretariat 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 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 Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © 1993 Copyright reserved to CEN members Ref. No. EN 20638:1993 E Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:24:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 20638:1993 2 © BSI 12-1999 Foreword This European Standard has been taken over by CEN/TC 172, Pulp, paper and board, from the work of ISO/TC 6, Paper, board and pulps, of the International Organization for Standardization (ISO). The document was submitted to formal vote and adopted by CEN as a European Standard without any modification. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 1994, and conflicting national standards shall be withdrawn at the latest by March 1994. According to the CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom. Contents Page Foreword2 1Scope and field of application3 2Definition3 3Apparatus3 4Preparation of sample3 5Procedure3 6Expression of results3 7Test report3 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:24:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 20638:1993 © BSI 12-19993 1 Scope and field of application This International Standard specifies a method for the determination of the dry matter content of pulp samples. This method is applicable to moist or air-dry pulp which does not contain any appreciable quantity of matter, other than water, volatile at the temperature specified for the drying. It is used, for example, with pulp samples taken or chemical and physical tests in the laboratory, which require concurrent determination of dry matter content. This method is not applicable to the determination of the dry matter content of slush pulp or to the determination of the saleable mass of pulp lots. 2 Definition For the purpose of this International Standard, the following definition applies. dry matter content of a pulp sample the ratio of the mass of a test piece, after drying to constant mass at a temperature of 105 ± 2 °C under specified conditions, to its mass at the time of sampling. The dry matter content is expressed as a percentage 3 Apparatus Ordinary laboratory apparatus, including: 3.1 Weighing containers, water-vapour proof and with tightly fitting lids. 3.2 Oven, capable of being controlled at 105 ± 2 °C, and suitably ventilated. 3.3 Balance, with an accuracy of 0,001 g. 3.4 Desiccator 4 Preparation of sample Cut or tear the pulp sample into pieces of suitable size, taking into account the method of test for which the dry matter content is to be determined. In handling the pulp, special precautions shall be taken to avoid any change in moisture content. Samples which have been kept in water-vapour proof containers shall be quickly cut and weighed to minimize any variation in moisture content. 5 Procedure Carry out all weighings to the nearest 0,001 g. Weigh about 10 g of pulp in the closed, previously dried and weighed container (3.1). After weighing, open the container and place it with test piece and lid in the oven (3.2) and heat at 105 ± 2 °C for a sufficiently long period (see the note) until constant mass is reached. The test piece is considered to have reached constant mass when the difference between two consecutive weighings is not more than 0,1 % of the original wet mass of the test piece. The drying period between two consecutive weighings shall be at least one-half of the minimum initial drying time. After drying, fit the lid on to the container and allow the test piece to cool in the desiccator (3.4) for 45 min. After cooling, equalize the air pressures outside and inside the container by quickly half opening and reclosing the lid. Weigh the container and its contents. NOTEDo not introduce new test pieces into the oven during drying. The preliminary drying period should be not less than 3 h and not more than 16 h. Carry out two determinations or as many as stated in the method of test for which the dry matter content is determined. 6 Expression of results The dry matter content X, expressed as a percentage by mass, is given by the formula Express the dry matter content to the first decimal place as a mean of all parallel determinations. 7 Test report The test report shall include the following particulars: a) reference to this International Standard; b) all the information necessary for complete identification of the sample; c) the results, expressed as a percentage; d) any unusual features observed in the course of the test; e) any operations not specified in this International Standard, or regarded as optional, which might have affected the results. where m1is the mass, in grams, of the pulp before drying; m2is the mass, in grams, of the pulp after drying. X m2 m1 - -100×= Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:24:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 20638:1994 ISO 638:1978 BSI 389 Chiswick High Road 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 amendment 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 would 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. 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