1、UDC 676.1/.2:620.1 :551.584.6 DEUTSCHE NORM November 1993 DIN Standard atmosphere for conditioning and testing of paper, board and pulps and procedure for monitoring the atmosphere and conditioning of samples (IS0 187 : 1990) English version of DIN EN 20 187 EN 20 187 This standard incorporates the
2、English version of Is0 1 87. Papier, Pappe und Zellstoff; Normalklima fr die Vorbehandlung und Prfung und Verfahren zur berwachung des Klimas und der Probenvorbehandlung (IS0 187:1990) Supersedes DIN IS0 187, September 1982 edition. European Standard EN 20 187 : 1993 has the status of a DIN Standard
3、. A comma is used as the decimal marker. National foreword This standard has been published in accordance with a decision taken by CEN/TC 172 to adopt, without alteration, International Standard IS0 187 as a European Standard. The responsible German body involved in its preparation was the Normenaus
4、schu Papier und Pappe (Paper and Board Standards Committee). DIN 54358 Part 1 is the standard corresponding to International Standard IS0 5269-2 referred to in clause 2 of the EN. Standard referred to (and not included in Normative references) DIN 54358 Part 1 Testing of pulps; preparation of labora
5、tory sheets for physical testing; Rapid-Koethen method Previous editions DIN 53102: 03.68, 05.77; DIN IS0 187: 09.82. Amendments IS0 187 having been adopted as a European Standard, the status of the corresponding DIN Standard (DIN IS0 187) has been changed accordingly. International Patent Classific
6、ation G O1 N 001/00 G O1 N 033/34 G 05 D 022/00 G 05 D 023/00 EN comprises 9 pages. buth Verlag GmbH, Berlin, has the exclusive right of sale for German Standards (DIN-Normen). DIN EN 20 187 Eng/. Price group 04.94 Sales No. 11 07 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 20187 September
7、1993 UDC 676.1/.2:620.1 :551.584.6 Descriptors: Paper, paperboard, pulps, conditioning, standard atmosphere. English version Paper, board and pulps Standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples (IS0 187:1990) Papier, carton e
8、t ptes; atmosphre nor- male de conditionnement et dessai et mthode de surveillance de latmosphre et de conditionnement des chantillons (IS0 187:1990) Papier, Pappe und Zellstoff; Normalklima fr die Vorbehandlung und Prfung und Verfahren zur berwachung des Klimas und der Probenvorbehandlung (IS0 187
9、: 1990) This European Standard was approved by CEN on 1993-09-06 and is identical to the IS0 Standard as referred to. 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 a
10、ny 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 b
11、y 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, Lu
12、xembourg, 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 Stassart 36, 8-1050 Brussels O 1993. Copyright reserved to all CEN members. Ref
13、. No. EN20187:1993E Page 2 EN20187:1993 Foreword In 1992, CEN/TC 172 Pulp, paper and board decided to submit International Standard IS0 187: 1990 Paper, board and pulps; standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples to Formal
14、 Vote. The result was positive. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, and conflicting national standards withdrawn, by March 1994 at the latest. In accordance with the CENKENELEC Internal Regulations, th
15、e 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 Kingdom. Endorsement notice The text of the International Standa
16、rd IS0 187: 1990 was approved by CEN as a European Standard without any modification. Introduction The physical properties of paper are affected materially by its moisture content which, in turn, is dependent on the humidity of the surrounding atmosphere. In order that tests may be made on paper in
17、a defined physical state, it is brought into equilibrium with an atmosphere of standardized temperature and relative humidity, and tested in that at- mosphere. The rnoisture content of a given paper in equilibrium with a given at- mosphere varies according to whether the equilibrium is reached by so
18、rption or by desorption of moisture. This hysteresis influences those physical properties that change with moisture content. Unless otherwise specified the equilibrium condition should be attained by the sorptive process. For a number of years three standard test atmospheres have been in common use:
19、 20 “CY65 % r.h : 23 “U50 Oh r.h. and 27 “C/65 04, r.h At the time of publication of this revision of IS0 187: 1977 the atmos- phere 23 “U50 90 r.h. is used almost exclusively in most countries and after 1 January 1993 is to be considered the IS0 standard test atmos- phere for testing of pulp. paper
20、 and board. However, the 23 “U50 Oh r.h. atmosphere is difficult to attain in some of the countries located in tropical zones, and in such countries the 27 “U65 % r.h. atmosphere is permitted. Until 1 January 1993 the 20 “Cl65 o/o r.h. atmosphere is ac- ceptable as a standard test atmosphere. 1 Scop
21、e 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 condilioning of laboratory prepared handsheels in accordance with IS0 5269-1, the standard atm
22、osphere is that defined in this Inter- national Standard but the procedure is different”. Page 3 EN 20187:1993 3 Definitions 2 Normative references The following standards contain provisions which. through reference in this text, constitute provisions of this Internatioiial Standard. At the time of
23、publi- cation, the editions indicated were valid. ,411 stan- dards are subject to revision, and parties to agreements based on this International S!andard are encouraged to investigate the possibility of ap- plying the most recent editions of the Standards in- dicated below. Members of IEC and IS0 m
24、aintain registers of currently valid International Standards. IS0 554: 1976, Standard atmospl?eres for conditioning andlor testing - Specifications. IS0 4677-1 .I 985, Atmospheres for condiiionlng and tesfing - Defer minalion of relative humdify - Pari I: Aspirated psychrometer method. IS0 5269-1.19
25、79, Pulps - Preparation of laboratory sheets for pAysic-.al testing - Part 7: Conventional sheet-former rnet+tod. IS0 5269-2.1980, Pulps - Preparation of laboratory sheets for pliysical testing - Part 2: Rapid-Koethen method. For the purposes of this International Standard, the following definitions
26、 apply. 3.1 relative humidity (r.h.): lhe 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 re- producible moisture content
27、 equilibrium between the sample and an atmosphere of specified temper- ature and relative humidity. This equilibrium is con- sidered to be attained when the results of two consecutive weighings of the sample, carried out at an interval of time of not less than 1 h, do not differ by more than a speci
28、fied amount. NOTE 1 The interval 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 a
29、ccepted as ensuring that the paper 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
30、a specific conditioning atmosphere in such a manner that a reproducible state of moisture content equilibrium is reached be- tween the sample and this atmosphere. 1) followed by conditioning by sorption of moisture. IS0 5269-1 requires pulp handsheets to be conditioned by desorption of moisture, whi
31、lst IS0 5269-2 requires drying Page 4 EN 20187:1993 5 Standard atmosphere The standard atmosphere for testing pulp, paper and paperboard shall be 23 “C $I 1 “C and (50 I 2) % r.h. In tropical countries an atmosphere of 27 “C 1 “C and (65 2) % r.h. may be used. NOTE 2 The temperature and relative hum
32、idity condi- tions are those specified in lSO554. The tolerances quoted are the reduced or close tolerances specified in IS0 554. A test atmosphere shall be deemed to he within the requirements of this International Standard if all the test results determined as described in annex A (see, in particu
33、lar, 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 moistiii-e content of the sample will be affected, are not permitted. Whenevei- the test atmosphere is known to have been outside the limits and
34、 if there is any charice that lhe moisture content of samples has been changed by such excursions, all samples must be recondilioned (repeating clause 6) before any further testing is done. NOTES 3 If it is known or suspected that the relative humidity has exceeded the upper limit to the extent that
35、 the moisture content may have increased, all samples except those prepared in accordance with IS0 5269-1, must be subjected to the preliminary low humidity treatment de- scribed in 6.1 before reconditioning. If it is known or suspected that the relative humidity has fallen below the limit to the ex
36、tent that the moisture coti- tent may have decreased, samples prepared in accord- ance with IS0 5269-1 should be discarded and new samples prepared. If this is not possible and the samples are tested, the circumstance must be reported 4 A recording hygrometer, either independent of or part of the co
37、ntrol system, should be in continuous operation in the room, but such hygrometer must not he used to assess whether the atmosphere meets the requirements of this International Standard unless it also meets the re- quirements of annex A of this standard. The hygrometer should respond rapidly to chang
38、es in relative humidity, for example, less than 1 min for a change in relative humidity of io Yo. 6 Conditioning procedure 6.1 Preconditioning of the sample For lests in which lhe, hysteresis of the equilibrium moisture content may lead to important errors, the sample shall be pre-conditioned before
39、 conditioning, for 24 h in air of relative humidity between 10 o/o and 35 OX, and a temperature not above 40 “C. If it is known that conditioning (6.2) will result in an equi- librium moisture content equivalent to that achieved by sorption (see Introduction) this preliminary treat- ment may be omit
40、ted. NOTE 5 Since the effect of hysteresis may not be known until after the event, it is recommended that precondi- tioning 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 sur- faces so that their moisture c
41、ontents attain a state of equilibrium with the water vapour in the atmos- phere. This equilibrium is considered to be attained when the results of two consecutive weighings at least 1 h apart do not differ by more than 0,25 % of the total mass (3.2). The interval between weighings needs to be longer
42、 for higher grammage products and the degree of agreement expected between successive weighings should take account of the known cycling characteristics of the test room. NOTE 6 With good air circulation, a conditioning period of 4 h is usually sufficient for paper. A minimum time of 5 h to 8 h will
43、 be required for heavy papers. Boards of higher grammage and specially treated materials may require a conditioning period of 48 h 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
44、 this International Standard; b) the nominal conditioning atmosphere used; c) the lime for which lhe sample was conditioned; d) whether the paper or the board was pre- conditioned before conditioning. Page 5 EN 20187: 1993 Annex A (norm at ive) Measurement of temperature and relative humidity A.1 Sc
45、ope This annex is based on IS0 4677-1:1985 and de- scribes the procedures for measurement of temper- ature and relative humidity to be used in determining compliance with this International Standard. It aims to specify those features which are essential for accurate measurement without speci- fying
46、a particular type of instrument. NOTE 7 Condensation type and impedance type hy- grometers may be wed provided they can be shown to be at least as accurate as the aspirated psychrometer. ventilation. The thermometers shall be mounted so that the axes of the sensors are parallel and separ- ated by a
47、distance of not less than three times the diameter of the wet bulb sensor. In the case of transverse ventilation both sensors may be located in the same air stream with the dry bulb off-set on the upstream side of the wet bulb. In the case of axial ventilation the direction of air flow shall be from
48、 the free end of the sensor to the sup- pori end and a separate cylindrical radiation shield, of internal diameter 1.75 to 3 times the wet bulb di- ameter, shall be provided for each sensor. The sensors shall be protecied from all sources of A.2 Apparatus heat radiation including that provided by th
49、e prox- imity of the operator. The air flow shall be provided Aspirated wet and dry bulb psychrometer, compris- by a fan located downstream from the sensors so ing the following essential components. that any heat generated by it will not affect the sen- sors, and exhaust air is directed away from the A.2.1 Thermometers source of incoming air These may be liquid-in-glass (either solid stem or enclosed scale type), thermocouples or electrical resistance thermometers with a working range of 10 “C or mote. They shall be accurate to within f 0.1 “C and the pair used in a
