() | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |[.]
Trang 1|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1149-2 : 1997
The European 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 Ð
Electrostatic properties
Part 2 Test method for measurement of
the electrical resistance through a
material (vertical resistance)
Trang 2This 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
ISBN 0 580 28692 4
BS EN 1149-2 : 1997
Amendments issued since publication
Amd 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 to 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 committee 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 using 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 back cover
Trang 3European Committee for Standardization Comite EuropeÂen de Normalisation EuropaÈisches Komitee fuÈr Normung
Central Secretariat: rue de Stassart 36, B-1050 Brussels
1997 CEN Ð All rights of exploitation in any form and by any means reserved worldwide for CEN national Members
Ref No EN 1149-2 : 1997 E
NORME EUROPE Â ENNE
EUROPA È 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 Ð Electrostatic properties Ð Part 2: Test method for measurement of the electrical resistance
through a material (vertical resistance)
VeÃtements de protection Ð ProprieÂteÂs
eÂlectrostatiques Ð
Partie 2: MeÂthode d'essai pour le mesurage de la
reÂsistance eÂlectrique aÁ travers un mateÂriau
(reÂsistance verticale)
Schutzkleidung Ð Elektrostatische Eigenschaften Ð Teil 2: PruÈfverfahren fuÈr 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 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 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
CEN members are the national standards bodies of Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,
Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and
United Kingdom
Trang 4Page 2
EN 1149-2 : 1997
Foreword
This European Standard has been prepared by
Technical 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 1998,
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 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
Trang 5Page 3
EN 1149-2 : 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 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 European 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
publications 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 Ð Electrostatic
properties Ð Part 1: Surface resistivity (Test methods and requirements)
3 Definition
For the purposes of this European Standard the
following definition applies:
3.1 Vertical Resistance RV
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 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 1149-1 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
d1= 50,4 mm which is secured, under a separating disc of high-insulating material (2), concentrically 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 d2= 69,2 mm and an outside diameter
d3= 89 mm, which under a separating ring of high-insulating material (6) is placed concentrically to a screening ring (7) with an outside diameter
d4= 100 mm lnsertion of a connector (8) insulated from the screening ring (7) provides a means of electrical contact to the metal guard 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 1014V A socket (11) provides 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 circumference 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 specimen 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 that the test and annular electrodes each have an equal pressure (approximately 0,225 N´cm22= 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 parts are made of steel with a density of 7,8 g´cm23 and the insulating parts are of Polymethylmethacrylate (PMMA), Polystyrene (PS) or Polycarbonate (PC) with a density
of approximately 1,19 g´cm23
Trang 6Page 4
EN 1149-2 : 1997
Dimensions in millimetres
1 2 3 4 5 6 7
Metal disc of the test electrode 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 1 Electrode assembly
Trang 7Page 5
EN 1149-2 : 1997
4 Coaxial plug-in connection
8 Connector
11 Socket
Figure 2 Circuit for measurement of vertical resistance RV
5.2 Ohmmeter or electrometer
Ohmmeter with a range of 105V to 1014V;
and a limit of errors of ±5 % for # 1012V,
±20 % for > 1012V
Alternatively an electrometer can be used with an
input impedance of not less than 1014V 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 thought 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/garment 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 suitable 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 sample/garment shall be conditioned prior to testing for at least 24 h and tested in the following atmosphere:
Air temperature: (23±1) ÊC 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 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 Testing
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
Trang 8Page 6
EN 1149-2 : 1997
lf the surface resistivity measured according to
EN 1149-1 of the test sample is less than 108V the
metal guard ring (5) shall not be connected to earth
during determination of RV, as otherwise an excessively
high fault current may cause an undue reduction of the
test voltage If this is the case 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
105V an appropriate low voltage may be applied and
shall be stated in the test report
lf necessary, vertical resistances of below 105V 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 four 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 of the material tested;
b) test atmosphere;
c) testing potential, in volts;
d) all five single measurements;
e) mean vertical resistance RV, 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 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 108V) is an additional beneficial property to low surface resistivity (see EN 1149-1) Often, however, this beneficial property 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 below 100 V) a high vertical resistance (e.g more than 105V) 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)
A.3 Calculation of the vertical resistivity has not been included, because this requires measuring the sample thickness and leads to increasing variability of results
A.4 The method described has shown a spread of results between different test laboratories up to a factor of 10 When the measured vertical resistance lies under 1010V the spread of results is less
Annex ZA (informative) Clauses of this European Standard addressing essential requirements or other provisions of EU Directives.
This European Standard has been prepared by CEN and supports essential requirements of EU Directive 89/686/EEC
WARNING Other requirements and other EU Directives may be applicable to the product(s) falling within the scope of this European Standard
The clauses of this European Standard are likely to support requirements of Directive 89/686/EEC, annex II, clause 3.8
Compliance with the clauses of this European Standard provides one means of conforming with the specific essential requirements of the Directive concerned and associated EFTA regulations
Trang 10389 Chiswick High Road
London
W4 4AL
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
BSI Ð British Standards Institution
BSI is the independent national body responsible for preparing British Standards It presents the UK view on standards in Europe and at the international level It is incorporated by Royal Charter
Revisions
British Standards are updated by amendment or revision Users of British Standards should make sure that they possess the latest amendments or editions
It is the constant aim of BSI to improve the quality of our products and services We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover Tel: 020 8996 9000 Fax: 020 8996 7400
BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards
Buying standards
Orders for all BSI, international and foreign standards publications should be addressed to Customer Services Tel: 020 8996 9001 Fax: 020 8996 7001
In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested
Information on standards
BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service Various BSI electronic information services are also available which give details on all its products and services Contact the Information Centre Tel: 020 8996 7111
Fax: 020 8996 7048
Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards For details of these and other benefits contact Membership Administration Tel: 020 8996 7002 Fax: 020 8996 7001
Copyright
Copyright subsists in all BSI publications BSI also holds the copyright, in the UK, of the publications of the international standardization bodies Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means ± electronic, photocopying, recording or otherwise ± without prior written permission from BSI This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained
If permission is granted, the terms may include royalty payments or a licensing agreement Details and advice can be obtained from the Copyright Manager
Tel: 020 8996 7070