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1、BS EN ISO 638:2008 ICS 85.040; 85.060 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Paper, board and pulps Determination of dry matter content Oven-drying method (ISO 638:2008) Licensed Copy: London South Bank University, South Bank University, 31/01/2009 04
2、:14, Uncontrolled Copy, (c) BSI This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2008 BSI 2008 ISBN 978 0 580 58856 3 Amendments/corrigenda issued since publication DateComments BS EN ISO 638:2008 National foreword This British Sta
3、ndard is the UK implementation of EN ISO 638:2008. It supersedes BS EN 20638:1993 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee PAI/11, Methods of test for paper, board and pulps. A list of organizations represented on this committee can be obtained
4、 on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Licensed Copy: London South Bank University, Sou
5、th Bank University, 31/01/2009 04:14, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 638 October 2008 ICS 85.040; 85.060Supersedes EN 20638:1993 English Version Paper, board and pulps - Determination of dry matter content - Oven-drying method (ISO 638:2008) Papie
6、rs, cartons et ptes - Dtermination de la teneur en matires sches - Mthode par schage ltuve (ISO 638:2008) Papier, Pappe und Faserstoff - Bestimmung des Trockengehaltes - Wrmeschrankverfahren (ISO 638:2008) This European Standard was approved by CEN on 13 September 2008. CEN members are bound to comp
7、ly 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 CEN Managem
8、ent Centre 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 CEN Management Centre has the same status as the
9、 official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovaki
10、a, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2008 CENAll rights of exploitation in any form and by any means reserved worldwide f
11、or CEN national Members. Ref. No. EN ISO 638:2008: E Licensed Copy: London South Bank University, South Bank University, 31/01/2009 04:14, Uncontrolled Copy, (c) BSI BS EN ISO 638:2008 EN ISO 638:2008 (E) 3 Foreword This document (EN ISO 638:2008) has been prepared by Technical Committee ISO/TC 6 “P
12、aper, board and pulps“ in collaboration with Technical Committee CEN/TC 172 “Pulp, paper and board” the secretariat of which is held by DIN. 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 April 2
13、009, and conflicting national standards shall be withdrawn at the latest by April 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights
14、. This document supersedes EN 20638:1993. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany,
15、Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 638:2008 has been approved by CEN as a EN ISO 638:2008 without any
16、 modification. Licensed Copy: London South Bank University, South Bank University, 31/01/2009 04:14, Uncontrolled Copy, (c) BSI BS EN ISO 638:2008 ISO 638:2008(E) ISO 2008 All rights reserved iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national
17、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
18、 organizations, governmental 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. International Standards are drafted in accordance with the rules g
19、iven in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at leas
20、t 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 638 was prepared by Technical Committee ISO/TC 6, Pap
21、er, board and pulps. This second edition cancels and replaces the first edition (ISO 638:1978), which has been technically revised. The scope has been changed to cover also paper and board instead of only pulps. Licensed Copy: London South Bank University, South Bank University, 31/01/2009 04:14, Un
22、controlled Copy, (c) BSI BS EN ISO 638:2008 ISO 638:2008(E) iv ISO 2008 All rights reserved Introduction Determination of dry matter content and moisture content are carried out for different purposes. This International Standard should be used when the dry matter content is needed to calculate the
23、results for chemical analysis or physical testing. An example of this is where the results of a chemical analysis for cadmium or manganese are required on the basis of the oven-dry mass of the sample. ISO 2871 should be used for the purpose of determining the average moisture content and the variati
24、on in moisture content (maximum and minimum values) of a lot. In the converting of paper and board, moisture content is important as it can have an effect on processes such as printing and copying. Moisture content can have an effect on curl and dimensional stability. ISO 41192 should be used in lab
25、oratory procedures or is referred to in other International Standards in which the concentration of an aqueous pulp suspension requires determination. Licensed Copy: London South Bank University, South Bank University, 31/01/2009 04:14, Uncontrolled Copy, (c) BSI BS EN ISO 638:2008 INTERNATIONAL STA
26、NDARD ISO 638:2008(E) ISO 2008 All rights reserved 1 Paper, board and pulps Determination of dry matter content Oven-drying method 1 Scope This International Standard specifies an oven-drying method for the determination of the dry matter in paper, board and pulp. The procedure is applicable to pape
27、r, board and pulp which does not contain any appreciable quantities of materials other than water that are volatile at the temperature of 105 C 2 C. It is used, for example, in the case of pulp, paper and board samples taken for chemical and physical tests in the laboratory, when a concurrent determ
28、ination of dry matter content is required. 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. NOTE ISO 2871 specifies the determination of moisture of a lot of paper and board; ISO 41193 specifies the
29、determination of stock concentration of pulps; ISO 801 (all parts)2 specifies the determination of saleable mass in lots. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undate
30、d references, the latest edition of the referenced document (including any amendments) applies. ISO 186, Paper and board Sampling to determine average quality ISO 7213, Pulps Sampling for testing 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.
31、1 dry matter content paper, board and pulps ratio of the mass of a test piece, after drying to constant mass at a temperature of 105 C 2 C under specified conditions, to its mass before drying NOTE The dry matter content is usually expressed as a percentage mass fraction. 3.2 constant mass paper, bo
32、ard and pulps mass reached by a test piece after drying at a temperature of 105 C 2 C until the difference between two successive dryings and weighings, separated in time by at least half the initial drying period, does not exceed 0,1 % mass fraction of the test piece before drying Licensed Copy: Lo
33、ndon South Bank University, South Bank University, 31/01/2009 04:14, Uncontrolled Copy, (c) BSI BS EN ISO 638:2008 ISO 638:2008(E) 2 ISO 2008 All rights reserved 4 Principle Test pieces taken from pulp, paper or board samples are weighed before and after drying to constant mass. From the mass of the
34、 test piece before and after drying, the dry matter content is calculated. 5 Apparatus 5.1 Balance, accurate to 1 mg, for weighing test pieces of 2 g and less; for larger test pieces, accurate to 0,05 % mass fraction of the original moisture-containing test piece. 5.2 Containers, water vapour-proof,
35、 with tightly fitting lids, and made from a material (e.g. glass or plastic) not affected by the conditions of test. 5.3 Drying oven, capable of maintaining the air temperature at 105 C 2 C, and suitably ventilated. 5.4 Desiccator. 6 Sampling If it is necessary to take a sample, ensure that it is re
36、presentative of the material being sampled and take special precautions to avoid any change in moisture content of the material that will be tested. Report the source of the sample and the sampling procedure used. Sampling from a lot shall be in accordance with ISO 186 for paper and board or ISO 721
37、3 for pulps. 7 Preparation of test pieces Do not use bare hands to handle the test pieces. Handle the test pieces and weighing containers with clean, dry, rubber or polyethylene gloves or tools. For determination of dry matter content of pulp, paper or board samples as received, place each test piec
38、e as soon as obtained in a tared container and close it immediately. From the sample, select test pieces of the required grammage which are representative of the sample. The test piece size depends on the grammage of the sample. The size can be varied from 1 g to 2 g for very low grammage samples (e
39、.g. papers) up to 50 g for high grammage samples (e.g. pulps or boards). Cut or tear the test piece into a suitable size, taking into account the method of test for which the dry matter content is to be determined. In handling the test piece, special precautions shall be taken to avoid any change in
40、 moisture content. Test pieces which have been kept in water-vapour proof containers shall be quickly cut and weighed to minimize any variation in moisture content. Prepare at least duplicate test pieces for each sample. 8 Procedure Carry out all weighings according to the accuracy required of the b
41、alance (5.1). Weigh a test piece in the closed, previously dried and weighed container (5.2). After weighing, open the container and place it with test piece and lid in the oven (5.3) and heat at 105 C 2 C for a sufficiently long period until constant mass is reached. The initial drying period shall
42、 be W 30 min for material of grammage u 200 g/m2 and W 60 min for grammage 200 g/m2. The initial drying period, even for highly moist samples, should not be more than 16 h. The test piece is considered to have reached constant mass when the difference between two consecutive weighings is not more th
43、an 0,1 % mass fraction of the test piece before drying. The drying period between two consecutive weighings shall be at least one-half of the minimum initial drying time. During these periods do not put any new test pieces in the oven. Licensed Copy: London South Bank University, South Bank Universi
44、ty, 31/01/2009 04:14, Uncontrolled Copy, (c) BSI BS EN ISO 638:2008 ISO 638:2008(E) ISO 2008 All rights reserved 3 After drying, fit the lid on to the container and allow the test piece to cool in the desiccator (5.4). After cooling, equalize the air pressures outside and inside the container by qui
45、ckly half-opening and reclosing the lid. Weigh the container and its contents. Carry out two determinations or as many as are stated in the method of test for which the dry matter content is to be determined. The results of the parallel determinations should not deviate by more than 0,5 % mass fract
46、ion from their mean. NOTE This International Standard is a reference method for determination of dry matter content based on oven dryness at 105 C. Other drying techniques (e.g. microwave and infrared drying) are available on the market, but results from those techniques do not accord with this Inte
47、rnational Standard. 9 Expression of results 9.1 Calculation Calculate the dry matter content, wdm , expressed as a percentage mass fraction, according to Equation (1): 1 dm 0 100 m w m = (1) where m0 is the mass, in grams, of the test piece before drying; m1 is the mass, in grams, of the test piece
48、after drying to constant mass. Calculate the mean dry matter content of the determinations, dm w, and express the result to the first decimal place. Moisture content can be calculated as described in Annex A. 10 Precision 10.1 Repeatability Different kinds of pulp, paper and board samples were teste
49、d in 11 different laboratories according to this International Standard. The pooled repeatability was determined and the results are shown in Table 1. Table 1 Repeatability for determination of dry matter content Sample Dry matter content % Coefficient of variation % Bleached kraft pulp 94,6 0,08 Unbleached kraft pulp 94,5 0,14 Copy paper 96,1 0,06 Uncoated paper 95,9 0,10 Carton board 1 94,0 0,08 Carton board 2 93,8 0,15 Licensed Copy: London South Bank University, South Bank University, 31/01/2
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