1、BRITISH STANDARD BS EN 20187:1993 ISO187:1990 Paper, board and pulps Standardatmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples The European Standard EN20187:1993 has the status of a British Standard UDC676.1.02:551.11.12BSEN20187:1993 Thi
2、s British Standard, having been prepared under the directionof the Paper and PrintingStandards Policy Committee, was published underthe authority of the Standards Board and comes intoeffect on 15 December1993 BSI 03-1999 The following BSI references relate to the work on this standard: Committee ref
3、erence PAM/11 Draft for comment90/37219DC ISBN 0 580 21881 3 Cooperating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austria Oesterreichisches N
4、ormungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y. France Association franaise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland Technological Institut
5、e of Iceland Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Asociacin Espaol
6、a de Normalizacin y Certificacin Sweden Standardiseringskommissionen i Sverige Switzerland Association suisse de normalisation United Kingdom British Standards Institution Amendments issued since publication Amd. No. Date CommentsBSEN20187:1993 BSI 03-1999 i Contents Page Cooperating organizations I
7、nside front cover National foreword ii Foreword 2 1 Scope 3 2 Normative references 3 3 Definitions 3 4 Principle 3 5 Standard atmosphere 3 6 Conditioning procedure 4 7 Test report 4 Annex A (normative) Measurement of temperature and relative humidity 5 Annex B (informative) Interdependence of temper
8、ature and relative humidity 7 Annex C (informative) Bibliography 9 National annex NA (informative) Committees responsible Inside back cover Table B.1 Change in relative humidity (r.h.) per0.5C change in temperature while water vapour content remains constant 7BSEN20187:1993 ii BSI 03-1999 National f
9、oreword This British Standard has been prepared under the direction of the Paper and Printing Standards Policy Committee and is the English language version of EN20187:1993 Paper, board and pulps Standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditi
10、oning of samples, published by the European Committee for Standardization (CEN). It is identical with ISO187:1990 published by the International Organization for Standardization (ISO). It supersedes BS3431:1973 which is withdrawn. EN20187 was produced as a result of international discussion in which
11、 the UK took active part. 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 page
12、s This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to10, an inside back cover 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 theinside
13、 front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN20187 September1993 UDC676.1/.2:551.11.12 Descriptors: Paper, paperboard, paper pulps, conditioning tests, standard atmosphere English version Paper, board and pulps Standard atmosphere for conditioning and testing and procedure for mo
14、nitoring theatmosphere and conditioning of samples (ISO187:1990) Papier, carton et ptes Atmosphre normale de conditionnement et dessai et mthode de surveillance de latmosphre et de conditionnement des chantillons (ISO187:1990) Papier, Pappe und Zellstoff Normalklima fr die Vorbehandlung und Prfung u
15、nd Verfahren zur berwachung des Klimas und der Probenvorbehandlung (ISO187:1990) This European Standard was approved by CEN on1993-09-06. 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 nationa
16、l 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 o
17、ther 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
18、, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart36, B-1050 Brussels 1993 Copyright reserved to CEN
19、members Ref. No. EN20187:1993EEN20187:1993 BSI 03-1999 2 Foreword This European Standard has been taken over by CEN/TC172 “Pulp, paper and board” from the work of ISO/TC6 “Paper, board and pulps” of the International Organization for Standardization(ISO). The document was submitted to formal vote an
20、d 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 March1994, and conflicting national standards shall be withdrawn at the latest by
21、March1994. 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 and United
22、Kingdom.EN20187:1993 BSI 03-1999 3 1 Scope This International Standard specifies the standard atmosphere for conditioning, and for testing pulp, paper and board, and also the procedures for measuring the temperature and relative humidity. For the conditioning of laboratory prepared handsheets in acc
23、ordance with ISO5269-1, the standard atmosphere is that defined in this International Standard but the procedure is different 1) . 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the tim
24、e of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maint
25、ain registers of currently valid International Standards. ISO554:1976, Standard atmospheres for conditioning and/or testing Specifications. ISO4677-1:1985, Atmospheres for conditioning and testing Determination of relative humidity Part1: Aspirated psychrometer method. ISO5269-1:1979, Pulps Preparat
26、ion of laboratory sheets for physical testing Part1: Conventional sheet-former method. ISO5269-2:1980, Pulps Preparation of laboratory sheets for physical testing Part2: Rapid-Koethen method. 3 Definitions For the purposes of this International Standard, the following definitions apply. 3.1 relative
27、 humidity (r.h.) the ratio, expressed as a percentage, of the actual water vapour content of the air to the water vapour content of air saturated with water vapour at the same temperature and pressure 3.2 conditioning a process of establishing a reproducible moisture content equilibrium between the
28、sample and an atmosphere of specified temperature and relative humidity. This equilibrium is considered to be attained when the results of two consecutive weighings of the sample, carried out at an interval of time of not less than1h, do not differ by more than a specified amount NOTE 1The interval
29、between weighings is dependent on the grammage of the sample and the degree of agreement expected between successive weighings should take account of the known cycling characteristics of the particular test room. The establishment of moisture content equilibrium is accepted as ensuring that the pape
30、r is in a stable physical state, but in special circumstances, conditioning may have to be prolonged until the desired physical equilibrium is attained. Such circumstances are not within the scope of this International Standard. 4 Principle Exposure of the sample to a specific conditioning atmospher
31、e in such a manner that a reproducible state of moisture content equilibrium is reached between the sample and this atmosphere. 5 Standard atmosphere The standard atmosphere for testing pulp, paper and paperboard shall be23C1C and(502)% r.h. In tropical countries an atmosphere of27C1C and(652)% r.h.
32、 may be used. NOTE 2The temperature and relative humidity conditions are those specified in ISO554. The tolerances quoted are the reduced or close tolerances specified in ISO554. A test atmosphere shall be deemed to be within the requirements of this International Standard if all the test results de
33、termined as described in Annex A (see, in particular,A.4.2) are within the prescribed limits. Even short-term excursions of temperature or humidity beyond these limits, to the extent that the equilibrium moisture content of the sample will be affected, are not permitted. Whenever the test atmosphere
34、 is known to have been outside the limits and if there is any chance that the moisture content of samples has been changed by such excursions, all samples must be reconditioned (repeating clause6) before any further testing is done. 1) ISO5269-1 requires pulp handsheets to be conditioned by desorpti
35、on of moisture, whilst ISO5269-2 requires drying followed by conditioning by sorption of moisture.EN20187:1993 4 BSI 03-1999 NOTE 3If it is known or suspected that the relative humidity has exceeded the upper limit to the extent that the moisture content may have increased, all samples except those
36、prepared in accordance with ISO5269-1, must be subjected to the preliminary low humidity treatment described in6.1 before reconditioning. If it is known or suspected that the relative humidity has fallen below the limit to the extent that the moisture content may have decreased, samples prepared in
37、accordance with ISO5269-1 should be discarded and new samples prepared. If this is not possible and the samples are tested, the circumstance must be reported. NOTE 4A recording hygrometer, either independent of or part of the control system, should be in continuous operation in the room, but such hy
38、grometer must not be used to assess whether the atmosphere meets the requirements of this International Standard unless it also meets the requirements of Annex A of this standard. The hygrometer should respond rapidly to changes in relative humidity, for example, less than1min for a change in relati
39、ve humidity of10%. 6 Conditioning procedure 6.1 Pre-conditioning of the sample For tests in which the hysteresis of the equilibrium moisture content may lead to important errors, the sample shall be pre-conditioned before conditioning, for24h in air of relative humidity between10% and35% and a tempe
40、rature not above40C. If it is known that conditioning(6.2) will result in an equilibrium moisture content equivalent to that achieved by sorption (see Introduction) this preliminary treatment may be omitted. NOTE 5Since the effect of hysteresis may not be known until after the event, it is recommend
41、ed that preconditioning be always carried out. 6.2 Conditioning The specimens of the sample shall be held such that the conditioning air has free access to all their surfaces so that their moisture contents attain a state of equilibrium with the water vapour in the atmosphere. This equilibrium is co
42、nsidered to be attained when the results of two consecutive weighings at least1h apart do not differ by more than0,25% of the total mass(3.2). The interval between weighings needs to be longer for higher grammage products and the degree of agreement expected between successive weighings should take
43、account of the known cycling characteristics of the test room. NOTE 6With good air circulation, a conditioning period of4h is usually sufficient for paper. A minimum time of5h to8h will be required for heavy papers. Boards of higher grammage and specially treated materials may require a conditioning
44、 period of48h or longer. 7 Test report The test report of any testing which is required to be done in this standard atmosphere shall include the following particulars: a) reference to this International Standard; b) the nominal conditioning atmosphere used; c) the time for which the sample was condi
45、tioned; d) whether the paper or the board was preconditioned before conditioning.EN20187:1993 BSI 03-1999 5 Annex A (normative) Measurement of temperature and relative humidity A.1 Scope This annex is based on ISO4677-1:1985 and describes the procedures for measurement of temperature and relative hu
46、midity to be used in determining compliance with this International Standard. It aims to specify those features which are essential for accurate measurement without specifying a particular type of instrument. NOTE 7Condensation type and impedance type hygrometers may be used provided they can be sho
47、wn to be at least as accurate as the aspirated psychrometer. A.2 Apparatus Aspirated wet and dry bulb psychrometer, comprising the following essential components: A.2.1 Thermometers These may be liquid-in-glass (either solid stem or enclosed scale type), thermocouples or electrical resistance thermo
48、meters with a working range of10C or more. They shall be accurate to within0,1C and the pair used in any instrument shall agree to within0,05C. Liquid-in-glass thermometers should be graduated in0,1 C scale divisions so that readings can be estimated to the nearest0,05C. Thermocouples and electrical
49、 resistance thermometers are usually connected to a digital display panel meter which rounds off to0,1C. However, a chart recorder with scale divisions of0,05C may be connected to provide a permanent record of dry bulb readings and also either wet bulb temperature or preferably, relative humidity computed electronically within the instrument. The sensing section of the thermometers shall not be less than1mm or more than4mm in diameter for transverse ventilation, and6mm for axial ventilation. Thermocouples and elec
