1、W 3404589 O033689 420 W EN 20811 June 1992 UDC 677.0741.076 : 677.017.63 : 620.1 Descriptors: Texciles, fabrics, tests, water resistance tests, fluid-ightness tests, hydrostatic presnw, pressure measurement English version Textiles - Deterrnination of resistance to water penetmtion - Hydrostatic pre
2、ssure test Etoffes - Dtermination de la rsistance la pntration de leau - Essai sous pression hydrostatique Druckversuch Tden - Ekshnm des Widerstandes gegen das Durchdringa von Wasser - Hydrostatisch er This European Standard was approved by CEN on 199246-26. CEN members are bound to comply with the
3、 CENKETLEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national stanard without any aiteration. Up-to-date lists and bibliographial references concerning such national standards may be obtained on application to the Central Secretariat or to
4、any CEN member. This European Standard exists in three officiai versions CEngliSh, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notined to the Central Secretariat has the same status as the officiai versions.
5、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 Comit Europen de Normaiisation E
6、uropisches Komitee fur Normung Central Secretanat: rue de Stassart 36, B-1050 Brussels O 1992 Copyright reserved to CEN members Ref. No. EN 20811 : 1992 E r Page 2 EN 20811 : 1992 CEN EN*Z081iL 92 3Li04589 0033b90 LYE M Foreword This European Standard has been taken over by CENK 248 Textiles and tex
7、tile products from the work of ISOK 38 “Ikxdes of the Intemationai rganization for Stanmon (Ise). The document was SubmiW to the GEN membem to the Unique Acceptance Procedure and was appmved without any modincatjon. National standads identical to this European Standard shai be published at the lates
8、t by 19921231 and conflicting national standards shall be Withdrawn at the latest by 1992-1231. Following the CEN/CENELEC Common Rules, the following countries are bound to implement this I EuropeariStanWAustria,Belgium,Denmark, Finland, Fiance, Germany, Greece,Iceiand, Ireland, I I*, Luxembourg, Ne
9、fi* b) an area of the fabric of 100 cm2 is subjected to stead- ily increasing water pressure from bdow or from above the fabric; ci no leakage of water takes place at the clamps during the test period see annex, clause A.1); ., ,- dl the specimen does not slip in the damps; el any tendency for penet
10、ration to occur at the clamped edge of the specimen is minimised see annex, clause A.1). 4.1.2 The water in contact with the test specimen should be distilled or fully deionized water maintained at either 20 f 2 OC or 27 f 2 OC. The chosen alternative shall be stated in the test report. (The use of
11、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 be 10 f 0,5cm or 60 i 3cmHzO/min*. Results obtained by the two different rates may not be the same. The chosen
12、 alter- native 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 of 0.5 cmH20 (see annex, clause A.2). Equipment which necessitates the use of smaller specimens, such as a circular area of 20 cm2, or of square spec
13、imens is still in use in some coun tries. Although these are not strictly in compliance with this Intemationa! Standard, they may be used for the time being and any variation from a cir cular specimen of area 100 cm2should be stated in the test report. This is an interim measure and it is intended t
14、hat this provision be deleted when the standard is reviewed 5 years after publication. * This relates to pressure in millibars 1 cmH20 = 1 mbar 1 cmH20 = 98.066 5 Pa (exactly) (1 rnbar = 100 Pa). and However, the actual measurement made is in conventional centimetres head of water per minute 1 CEN E
15、N*;708LL 92 9 3404589 0033692 TL5 9 BS 2823 : 1982 5 Conditioning Conditioning and testing shall be carried out according to IS0 139. 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 f
16、olding it sharply and do not treat it in any way (e.g. by ironing it) other than by conditioning. 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. Do not take into accou
17、nt very fine droplets which do not grow after 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 occ
18、urs at a pressure less than the lowest pressure 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
19、according to clause 7. Report the individual results and the mean result in conventional centimetres of water. Areas with deep creases or fold marks shall not be tested. 9 Test report 7 Test procedure The test report shall include the following information Provide freshly distilled water for each sp
20、ecimen tested (see annex, clause A.3). Wipe all water from the clamping surfaces. Clamp the con- ditioned specimen in the test head so that the face of the fabric hili 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 pri
21、or to the start of the test. Subject the specimen immediately to increasing water pressure. Watch continuously for evidence of penetration by water. . Record the pressure, as conventional centimetres of water, at which water first appears at the third place in the specimen. The accuracy for recordin
22、g the pressure shall be the following : - until 1 mH20 : 0.5 cm - more than 1 mH20 and until 2 mH20 : 1 cm more than 2 mH20 : 2 cm - a) reference to this International Standard; b) the atmosphere used (standard temperate or standard tropical or other atmosphere); c) the temperature of the water (20
23、or 27 OC or other temperature); di whether the water pressure was applied from below or from above the test specimen; e) the rate of increase of water pressure, (10 or 60 cmH20/mini; fi which side of the fabric was tested; g) any variation in size or shape of the test specimen; h) the individual res
24、ults and their mean. 2 - - I CEN ENu20811 92 m 3404589 O033693 951 BS 2823 : 1982 Annex Advice on conducting the test (Forms part of the standard) A.l Clamping the specimen(s1 With some forms of apparatus, it has been found that correct conditions of clamping can be attained if the clamps are faced
25、with a suitable grade of rubber. A.2 Manometer 3 a) It is necessary to provide a manometer of suitable range. A manometer which provides for pressures up to 1 mH20 is suitable for fabrics similar in construction to gaberdines; for fabrics of closer construction it is advisable to use a manometer whi
26、ch provides for pressures up to 2 mHp. 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 appara
27、tus, such a leakage can markedly reduce 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 heads) and rises to come into contact
28、 with the specimen, the surface of the water in the testing heads) may be cleaned in one of the following ways, stated in order of preference : a) freshly distilled water. Empty the testing headis) and refill with sufficient b) Allow the distiiled water to overflow from the testing heads) so that th
29、e surface of the water is cleared. Sweep the surface cf the water with a glass slide freshly coated with paraffin wax. c) Allow the distilled water to overflow from the testing headis) 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, such as diethyl ether, in the laboratory when this test is being carried out can affect the results.
