BS EN 1149-2-1997 Protective clothing - Electrostatic properties - Test method for measurement of the electrical resistance through a material (vertical resistance)《防护服装 静电特性 通过材料的.pdf

1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 1149-2 : 1997 The E

2、uropean Standard EN 1149-2 : 1997 has the status of a British Standard ICS 13.340.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Protective clothing Electrostatic properties Part 2. Test method for measurement of the electrical resistance through a material (vertical resis

3、tance)This British Standard, having been prepared under the direction of the Health and Environment Sector Board, was published under the authority of the Standards Board and comes into effect on 15 December 1997 BSI 1997 ISBN 0 580 28692 4 BS EN 1149-2 : 1997 Amendments issued since publication Amd

4、. No. Date Text affected National foreword This British Standard is the English language version of EN 1149-2 : 1997. The UK participation in its preparation was entrusted to Technical Committee PH/3/1, Clothing for protection against general hazards, which has the responsibility to: aid enquirers t

5、o understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this co

6、mmittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled International Standards Correspondence Index, or by u

7、sing the Find facility of the BSI Standards Electronic Catalogue. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 6, an inside back cover and a b

8、ack cover.CEN European Committee for Standardization Comite Europe en de Normalisation Europa isches Komitee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN

9、 1149-2 : 1997 E EUROPEAN STANDARD EN 1149-2 NORME EUROPE ENNE EUROPA ISCHE NORM August 1997 ICS 13.340.10 Descriptors: Personal protective equipment, accident prevention, protective clothing, electrostatic protection, tests, measurements, electrical resistance English version Protective clothing El

10、ectrostatic properties Part 2: Test method for measurement of the electrical resistance through a material (vertical resistance) Ve tements de protection Proprie te s e lectrostatiques Partie 2: Me thode dessai pour le mesurage de la re sistance e lectrique a travers un mate riau (re sistance vertic

11、ale) Schutzkleidung Elektrostatische Eigenschaften Teil 2: Pru fverfahren fu r die Messung des elektrischen Widerstandes durch ein Material (Durchgangswiderstand) This European Standard was approved by CEN on 1997-07-24. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which

12、 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 CEN member. This European Stand

13、ard 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. CEN members are the national stand

14、ards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Page 2 EN 1149-2 : 1997 BSI 1997 Foreword This European Standard has been prepared by Technica

15、l Committee CEN/TC 162, Protective clothing including hand and arm protection and lifejackets, 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 February 199

16、8, and conflicting national standards shall be withdrawn at the latest by February 1998. The annex A is informative. For relationship with EU Directive(s), see informative annex ZA, which is an integral part of this standard. According to the CEN/CENELEC Internal Regulations, the national standards

17、organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.Page 3 EN 1149-2

18、: 1997 BSI 1997 Introduction This European Standard is part of a series of test methods and requirements for electrostatic properties of protective clothing. The European Standard has been divided into a number of Parts due to the differing fields of application and materials. 1 Scope This European

19、Standard specifies a test method for measuring the electrical vertical resistance of protective clothing materials. This European Standard is not applicable for specifying protection against mains voltages. NOTE. Further information is given in the informative annex A. 2 Normative references This Eu

20、ropean Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publicatio

21、ns apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 1149-1 : 1995 Protective clothing Electrostatic properties Part 1: Surface resistivity (Test methods and requirements) 3 Defi

22、nition For the purposes of this European Standard the following definition applies: 3.1 Vertical Resistance R V The electrical resistance through a material in ohms as determined by using specified electrodes. 4 Test principle Electrodes are placed on opposite surfaces of the material to be tested.

23、A d.c. potential is applied to the electrodes and the vertical resistance of the test material is determined. 5 Test apparatus 5.1 Electrode assembly 5.1.1 General Electrical contact with the test material shall be established by means of an electrode assembly identical to electrode type A of EN 114

24、9-1. This electrode assembly also determines the measuring geometry, see figure 1. 5.1.2 Test electrode The test electrode consists of a metal disc (1) approximately 3 mm thick and with a diameter d 1 = 50,4 mm which is secured, under a separating disc of high-insulating material (2), concentrically

25、 to a metal guard plate (3). A coaxial plug-in connection (4) provides a means of electrical contact to the metal disc and the guard plate. 5.1.3 Annular electrode The annular electrode consists of a metal guard ring (5) of approximately 3 mm thickness with an inside diameter d 2 = 69,2 mm and an ou

26、tside diameter d 3 = 89 mm, which under a separating ring of high-insulating material (6) is placed concentrically to a screening ring (7) with an outside diameter d 4 = 100 mm. lnsertion of a connector (8) insulated from the screening ring (7) provides a means of electrical contact to the metal gua

27、rd ring (5). 5.1.4 Base plate electrode The base plate electrode consists of a metal disc (9) (110 0,2) mm diameter and approximately 12 mm thickness, equipped on the lower side with an insulating layer (10) of a maximum thickness of 1 mm and insulation not less than 10 14 V. A socket (11) provides

28、electrical contact. 5.1.5 Construction of the assembly The test electrode is placed concentrically to the annular electrode and shall be easily movable within it. For completion of electrical contact, sprung balls shall be inserted into three holes (13) distributed at equal distances along a circumf

29、erence of the contact area between the metal guard plate (3) and the screening ring (7) of the test and annular electrodes. The spring pressure thus asserted shall be weak enough for any extra friction to be negligible. The surfaces of electrodes (1), (5) and (9) which come into contact with the spe

30、cimen shall be made from the same material, so that in the case of samples containing electrolyte, no electrolysis junctions can occur. The overall mass of test and annular electrodes shall be (1020 20) g, exerting a contact pressure on the test material of approximately 10 N. ln order to ensure tha

31、t the test and annular electrodes each have an equal pressure (approximately 0,225 Ncm 22 = 2,25 kPa) the mass of the test electrode shall be (460 10) g and the mass of the annular electrode shall be (560 10) g. Figure 1 is a construction diagram showing suitable dimensions assuming that the metal p

32、arts are made of steel with a density of 7,8 gcm 23 and the insulating parts are of Polymethylmethacrylate (PMMA), Polystyrene (PS) or Polycarbonate (PC) with a density of approximately 1,19 gcm 23 .Page 4 EN 1149-2 : 1997 BSI 1997 Dimensions in millimetres 1 2 3 4 5 6 7 Metal disc of the test elect

33、rode Insulating disc of the test electrode Guard plate of the test electrode Coaxial plug-in connection Metal guard ring of the annular electrode Insulating ring Screening ring 8 9 10 11 12 13 Connector Metal disc of the base plate electrode Insulating layer Socket Test material Bore for ball Figure

34、 1. Electrode assemblyPage 5 EN 1149-2 : 1997 BSI 1997 4 Coaxial plug-in connection 8 Connector 11 Socket Figure 2. Circuit for measurement of vertical resistance R V 5.2 Ohmmeter or electrometer Ohmmeter with a range of 10 5 V to 10 14 V; and a limit of errors of 5 % for# 10 12 V, 20 % for 10 12 V.

35、 Alternatively an electrometer can be used with an input impedance of not less than 10 14 V and a separate d.c. source with an inbuilt safety resistor. 5.3 Cleaning agent applicable to the electrodes Use an appropriate cleaning agent, e.g. propan-2-ol or ethanol. NOTE. Certain cleaning agents though

36、t appropriate, such as propan-2-ol or ethanol, are highly flammable and toxic. It is recommended to resort to appropriate collective or personal measures of protection in order to avoid ignition, breathing of vapours and contact of such products with skin, eyes and clothing. 6 Specimens or sample/ga

37、rment and conditioning 6.1 Specimens or sample/garment From a sample or garment, five test specimens shall be cut, each of a size between the overall dimensions of the annular electrode and base plate electrode. lf a sample/garment is to be tested, then measurements shall be made at five different s

38、uitable places. Handle the specimens only at the edges to avoid contamination. NOTE. The specimens can be from the same production lots as the materials that have been used for the manufacture of the delivery sample of the protective clothing. 6.2 Conditioning and testing atmosphere The specimens or

39、 sample/garment shall be conditioned prior to testing for at least 24 h and tested in the following atmosphere: Air temperature: (23 1) C Relative humidity: (25 5) % NOTE. For specific purposes other atmospheres may be required (see annex A). 7 Test procedure 7.1 Cleaning Clean the lower surfaces of

40、 the test and annular electrode, and the upper surface of the base plate electrode by wiping with a paper tissue which has been moistened with one of the cleaning agents (see 5.3). 7.2 Isolation test of the base plate electrode Testing shall be done according to 5.4.2 of EN 1149-1 : 1995. 7.3 Testin

41、g The base plate electrode shall be placed with the non-isolated side upwards. The test material shall be placed on the base plate and the test electrode and the annular electrode shall be placed concentrically on top of it. The circuit is formed as shown in figure 2.Page 6 EN 1149-2 : 1997 BSI 1997

42、 lf the surface resistivity measured according to EN 1149-1 of the test sample is less than 10 8 V the metal guard ring (5) shall not be connected to earth during determination of R V , as otherwise an excessively high fault current may cause an undue reduction of the test voltage. If this is the ca

43、se only specimens, and not samples/garments, shall be tested. Apply a potential of (100 5) V and after (15 1) s determine the vertical resistance using the ohmmeter or electrometer. lf the vertical resistance is less than 10 5 V an appropriate low voltage may be applied and shall be stated in the te

44、st report. lf necessary, vertical resistances of below 10 5 V may be determined by measuring the current through a suitable ammeter connected in series with the specimen and calculating the ratio of the applied potential to the current. Repeat this procedure on the four other test specimens or on fo

45、ur different places on the garment. 8 Calculation and expression of results Calculate the arithmetical mean of the five measured values of the vertical resistance. 9 Test report ln the test report reference shall be made to this European Standard and the following shall be reported: a) description o

46、f the material tested; b) test atmosphere; c) testing potential, in volts; d) all five single measurements; e) mean vertical resistance R V , in ohms; f) any variations from this European Standard; g) date of test. Annex A (informative) Explanatory notes A.1 The vertical resistance can either be an

47、important property in itself or in addition to the surface resistivity for clothing materials. For electrostatic dissipative clothing a low vertical resistance (e.g. less than 10 8 V) is an additional beneficial property to low surface resistivity (see EN 1149-1). Often, however, this beneficial pro

48、perty cannot be relied on as insulating clothing worn below the outer garment may impede the contact of the outer garment with the skin and hence impede electrostatic charge from dissipating directly to the body. For special purposes such as protective clothing for arc welders (voltages usually belo

49、w 100 V) a high vertical resistance (e.g. more than 10 5 V) may be required to provide a certain degree of insulation. It should be noted that, generally, insulation properties tend to decrease as the relative humidity increases. A.2 A specific standard for protective clothing referring to this European Standard should define the required pretreatment (e.g. number of cleansing cycles), conditioning and testing atmospheres and the performance level (e.g. minimum or maximum vertical resistance)