1、BRITISH STANDARD BS EN 20811:1992 ISO811:1981 Incorporating Amendment No.1 Textiles Determination of resistance to water penetration Hydrostatic pressure test The European Standard EN20811:1922 has the status of a BritishStandard UDC 677.0741.076:677.017.63:620.1BSEN20811:1992 This BritishStandard,
2、having been prepared under the directionof the Fibres, Yarns andFabrics Standards Committee, was published underthe authority of the Board ofBSI and comes into effect on 31March1982 BSI02-2000 First published February1957 First revision October1968 Second revision The following BSI references relate
3、 to the work on this standard: Committee reference TCM/25 Draft for comment79/36054 DC ISBN 0 580 12678 1 Cooperating organizations The Fibres, Yarns and Fabrics Standards Committee, under whose direction this BritishStandard was prepared, consists of representatives from the following: Association
4、of Jute Spinners and Manufacturers British Nonwoven Manufacturers Association British Railways Board British Textile Employers Association* Central Council of the Irish Linen Industry Consumer Standards Advisory Committee of BSI Department of Industry (Chemicals and Textiles) Institute of Purchasing
5、 and Supply International Wool Secretariat* Knitting Industries Federation Ltd.* Manchester Chamber of Commerce and Industry Man-made Fibres Producers Committee* Ministry of Defence* Narrow Fabrics Federation Textile Institute* Warp Knitters Association Ltd. The organizations marked with an asterisk
6、 in the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this BritishStandard: Confederation of British Wool Textiles Limited Hollings College for the Food and Fashion Industries Manchester Chamber of Commerce (Testing Ho
7、use and Laboratories) Soap and Detergent Industry Association Society of Dyers and Colourists Society of Motor Manufacturers and Traders Limited Textile Research Council Amendments issued since publication Amd. No. Date of issue Comments 7006 November 1992 Indicated by a sideline in the marginBSEN20
8、811:1992 BSI 02-2000 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 1 Scope and field of application 3 2 Reference 3 3 Principle 3 4 Apparatus 3 5 Conditioning 3 6 Test specimens 3 7 Test procedure 3 8 Calculation and expression of results 4 9 Test repor
9、t 4 Annex Advice on conducting the test 5 Publication referred to Inside back coverBSEN20811:1992 ii BSI 02-2000 National foreword This revision of BS2823 has been prepared under the direction of the Fibres, Yarns and Fabrics Standards Committee, and is identical with ISO811:1980 “Textile fabrics De
10、termination of resistance to water penetration Hydrostatic pressure test” published by the International Organization for Standardization (ISO). BS2823:1968 is therefore withdrawn. In1992 the European Committee for Standardization (CEN) accepted ISO811:1981 as European Standard EN20811:1992. As a co
11、nsequence of implementing the European Standard this BritishStandard is renumbered as BSEN20811 and any reference to BS2823 should be read as a reference to BSEN20811. Terminology and conventions. The text of the International Standard has been approved as suitable for publication, as a BritishStand
12、ard, without deviation. Some terminology and certain conventions are not identical with those used in BritishStandards; attention is especially drawn to the following. Where the words “International Standard” appear, they should be read as “BritishStandard”. The comma has been used throughout as a d
13、ecimal marker. In BritishStandards 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
14、British Standard does not of itself confer immunity from legal obligations. Cross-reference International Standard Corresponding British Standard ISO139:1973 BS EN20139:1992 Textiles Standard atmospheres for conditioning and testing (Identical) Summary of pages This document comprises a front cover,
15、 an inside front cover, pagesi andii, theEN title page, pages2 to6, 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 the inside front cover.EUROPEAN STANDARD NORME EUR
16、OPENNE EUROPISCHE NORM EN20811 June1992 UDC 677.0741.076:677.017.63:620.1 Descriptors: Textiles, fabrics, tests, water resistance tests, fluid-tightness tests, hydrostatic pressure, pressure measurement English version Textiles Determination of resistance to water penetration Hydrostatic pressure te
17、st Etoffes Dtermination de la rsistance la pntration de leau Essai sous pression hydrostatique Textilien Bestimmung des Widerstandes gegen das Durchdringen von Wasser Hydrostatischer Druckversuch This European Standard was approved by CEN on1992-06-26. CEN members are bound to comply with the CEN/CE
18、NELEC 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
19、 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. CE
20、N 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 Normalisation Eur
21、opisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1992 Copyright reserved to CEN members Ref. No. EN20811:1992 EEN20811:1992 BSI 02-2000 2 Foreword This European Standard has been taken over by CEN/TC248 “Textiles and textile products” from the work of ISO/TC38 “Te
22、xtiles” of the International Organization for Standardization(ISO). The document was submitted to the CEN members to the Unique Acceptance Procedure and was approved without any modification. National standards identical to this European Standard shall be published at the latest by1992-12-31 and con
23、flicting national standards shall be withdrawn at the latest by1992-12-31. Following the CEN/CENELEC Common Rules, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Nor
24、way, Portugal, Spain, Sweden, Switzerland, UnitedKingdom.EN20811:1992 BSI 02-2000 3 1 Scope and field of application This International Standard specifies a hydrostatic pressure method for determining the resistance of fabrics to penetration by water. The method is primarily intended for dense fabri
25、cs, e.g.ducks, tarpaulins and tentings. 2 Reference ISO139, Textiles Standard atmospheres for conditioning and testing. 3 Principle The hydrostatic head supported by a fabric is a measure of the opposition to the passage of water through the fabric. A specimen is subjected to a steadily increasing p
26、ressure of water on one face, under standard conditions, until penetration occurs in three places. The pressure at which the water penetrates the fabric at the third place is noted. The water pressure may be applied from below or from above the test specimen. The chosen alternative should be stated
27、in the test report. The result is immediately relevant to the behaviour of fabric articles which are subjected to water pressure for short or moderate periods of time. 4 Apparatus 4.1 The apparatus used for the test should be designed to comply with the following conditions. 4.1.1 It should be possi
28、ble to clamp the specimen of fabric in such a way that a) it is horizontal and is not bulging; b) an area of the fabric of100cm 2 1)is subjected to steadily increasing water pressure from below or from above the fabric; c) no leakage of water takes place at the clamps during the test period (see Ann
29、ex, clauseA.1); d) the specimen does not slip in the clamps; e) any tendency for penetration to occur at the clamped edge of the specimen is minimised (seeAnnex, clauseA.1). 4.1.2 The water in contact with the test specimen should be distilled or fully deionized water maintained at either20 2 C or27
30、2 C. The chosen alternative shall be stated in the test report. (The use of water at the higher temperature will yield lower values of hydrostatic head; the magnitude of this effect may vary from fabric to fabric.) 4.1.3 The rate of increase of water pressure shall be10 0,5cm or60 3cmH 2 O/min 2) .
31、Results obtained by the two different rates may not be the same. The chosen alternative shall be stated in the test report. 4.1.4 A manometer connected to the testing head(s) should allow pressures to be read to an accuracy of0,5cmH 2 O (see Annex, clauseA.2). 5 Conditioning Conditioning and testing
32、 shall be carried out according to ISO139. If so agreed, conditioning and testing may be carried out in the ambient temperature. 6 Test specimens After receipt, handle the fabric as little as possible, avoid folding it sharply and do not treat it in any way (e.g.by ironing it) other than by conditio
33、ning. Take at least five test specimens from different places in the fabric so that they represent the material as fully as possible. The fabric may be tested without cutting specimens. Areas with deep creases or fold marks shall not be tested. 7 Test procedure Provide freshly distilled water for ea
34、ch specimen tested (see Annex, clauseA.3). Wipe all water from the clamping surfaces. Clamp the conditioned specimen in the test head so that the face of the fabric will be in contact with the water. The clamping shall be carried out in such a way that water will not be forced through the specimen p
35、rior to the start of the test. Subject the specimen immediately to increasing water pressure. Watch continuously for evidence of penetration by water. 1) Equipment which necessitates the use of smaller specimens, such as a circular area of20cm 2 , or of square specimens is still in use in some count
36、ries. Although these are not strictly in compliance with this International Standard, they may be used for the time being and any variation from a circular specimen of area100cm 2should be stated in the test report. This is an interim measure and it is intended that this provision be deleted when th
37、e standard is reviewed5years after publication. 2) This relates to pressure in millibars. 1cmH 2 O 1mbar and1cmH 2 O=98,0665Pa (exactly)(1mbar=100Pa). However, the actual measurement made is in conventional centimetres head of water per minute.EN20811:1992 4 BSI 02-2000 Record the pressure, as conve
38、ntional centimetres of water, at which water first appears at the third place in the specimen. The accuracy for recording the pressure shall be the following: until1mH 2 O:0,5cm more than1mH 2 O and until2mH 2 O:1cm more than2mH 2 O:2cm Do not take into account very fine droplets which do not grow a
39、fter being formed. Do not count subsequent drops which penetrate through the same place in the fabric. Note whether the penetration of water at the third place occurs at the edge of the clamp and reject as unsatisfactory any test in which such penetration occurs at a pressure less than the lowest pr
40、essure recorded for the other specimens from the same sample. Test further specimens until the requisite number of satisfactory results is obtained. 8 Calculation and expression of results Calculate the mean of the pressures recorded for the specimens tested according to clause7. Report the individu
41、al results and the mean result in conventional centimetres of water. 9 Test report The test report shall include the following information: a) reference to this International Standard; b) the atmosphere used (standard temperate or standard tropical or other atmosphere); c) the temperature of the wat
42、er(20 or27C or other temperature); d) whether the water pressure was applied from below or from above the test specimen; e) the rate of increase of water pressure,(10or60cmH 2 O/min); f) which side of the fabric was tested; g) any variation in size or shape of the test specimen; h) the individual re
43、sults and their mean.EN20811:1992 BSI 02-2000 5 Annex Advice on conducting the test (Forms part of the standard) A.1 Clamping the specimen(s) With some forms of apparatus, it has been found that correct conditions of clamping can be attained if the clamps are faced with a suitable grade of rubber. A
44、.2 Manometer a) It is necessary to provide a manometer of suitable range. A manometer which provides for pressures up to1mH 2 O is suitable for fabrics similar in construction to gaberdines; for fabrics of closer construction it is advisable to use a manometer which provides for pressures up to2mH 2
45、 O. b) If more than one testing head is used in conjunction with the manometer, means shall be provided for separately disconnecting them. This is to prevent a high rate of leakage through test specimens already penetrated at three places. With most forms of apparatus, such a leakage can markedly re
46、duce the rate of increase of pressure on the remaining specimens still under test. A.3 Provision of clean water surface If the instrument used is of the type in which the water to be used for testing is contained in the testing head(s) and rises to come into contact with the specimen, the surface of
47、 the water in the testing head(s) may be cleaned in one of the following ways, stated in order of preference: a) Empty the testing head(s) and refill with sufficient freshly distilled water. b) Allow the distilled water to overflow from the testing head(s) so that the surface of the water is cleared
48、. Sweep the surface of the water with a glass slide freshly coated with paraffin wax. c) Allow the distilled water to overflow from the testing head(s) so that the surface of the water is cleared. A.4 Presence of vapours of volatile organic liquids The presence of vapours of volatile organic liquids
49、, such as diethyl ether, in the laboratory when this test is being carried out can affect the results.6 blankBSEN20811:1992 BSI 02-2000 Publication referred to See national foreword.BS EN 20811:1992 ISO811:1981 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions BritishStandards are updated by amendment or revi
