1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 1853:2011Conducting and dissipativerubbers, vulcanized orthermoplastic Measurementof resistivityBS ISO 1853:2011 BRITISH STANDARDNational forewordThis British Standard is
2、the UK implementation of ISO 1853:2011.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/22, Physical testing of rubber.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the
3、necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 66332 1ICS 83.060Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Com
4、mittee on 30 September 2011.Amendments issued since publicationDate Text affectedBS ISO 1853:2011Conducting and dissipative rubbers, vulcanized or thermoplastic Measurement of resistivityCaoutchoucs vulcaniss ou thermoplastiques conducteurs et dissipants Mesurage de la rsistivit ISO 2011Reference nu
5、mberISO 1853:2011(E)Third edition2011-08-01ISO1853INTERNATIONAL STANDARDBS ISO 1853:2011ISO 1853:2011(E)COPYRIGHT PROTECTED DOCUMENT ISO 2011All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanica
6、l, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublis
7、hed in Switzerlandii ISO 2011 All rights reservedBS ISO 1853:2011ISO 1853:2011(E)Contents PageForeword ivIntroduction v1 Scope 12 Normative reference .13 Method 1 13.1 Apparatus and materials .13.2 Test piece .23.3 Number of test pieces 33.4 Procedure 33.5 Expression of results .43.6 Test report .44
8、 Method 2 44.1 Apparatus and materials .44.2 Test piece .54.3 Number of test pieces 54.4 Procedure 54.5 Expression of results .64.6 Test report .65 Method 3 75.1 Apparatus and materials .75.2 Test piece .75.3 Number of test pieces 85.4 Procedure 85.5 Expression of results .85.6 Test report .8Annex A
9、 (informative) Solid-state electrometer 10 ISO 2011 All rights reserved iiiBS ISO 1853:2011ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried ou
10、t through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO co
11、llaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International St
12、andards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements o
13、f this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 1853 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 2, Testing and analysis.This third edition cancels and replaces the
14、 second edition (ISO 1853:1998), which has been technically revised, mainly to add another two methods (methods 2 and 3).ISO 1853:2011(E)iv ISO 2011 All rights reservedBS ISO 1853:2011IntroductionRubber is normally regarded as a material of high electrical resistivity; consequently, it is widely use
15、d as an insulator. However, the incorporation of various materials, in particular certain forms of carbon black, greatly reduces the electrical resistance so that volume resistivities between 1013m and 0,01 m are obtainable.There are various technical and industrial purposes for which rubber with a
16、reduced resistivity is a useful material, the most frequent application being for the dissipation of static charges. In certain circumstances, a lower limit of resistance has to be imposed on a product with this latter application, as a safety precaution to prevent its ignition or to prevent severe
17、shock to a person in contact with it, in the event of faulty insulation or nearby electrical equipment.Products which, while conducting away static charges, are sufficiently insulating to fulfill the safety requirements above are termed dissipative rubbers (the description antistatic rubber is also
18、used). Products which do not fulfill the safety requirements are termed “conducting” rubbers. Since the dimensions of the product are involved, it is not possible to define a suitable range of volume resistivity for either of these classes, but only a range of resistance values between defined point
19、s. However, conductive materials are generally considered to have a resistivity below 106m and dissipative materials to have a resistivity between 105m and 1010m.The principal hazard, apart from static electricity, in most buildings and with most electrical equipment is from leakage currents from no
20、rmal voltage supply mains. To guard against these hazards, it is recommended that the lower limit of resistance for a dissipative rubber product be 5 104 for 250 V mains supplies, that is a maximum current of 5 mA. The limit can be proportionally less for lower voltages.The maximum resistance which
21、will permit the dissipation of static charges depends on the rate of generation of charge required to produce the minimum voltage which can be regarded as a hazard in a particular application.Effect of temperature changes and strain on conducting and dissipative rubbersThe resistance of rubber and p
22、lastics made conductive by the addition of carbon black is very sensitive to strain and temperature history, since resistance depends on the structural configuration of the carbon particles in the matrix.Under normal conditions of service with varying temperature and strain history, the resistance o
23、f a sample of a given material can vary considerably, for example by a hundred or more times, between freshly strained materials at room temperatures and material which has remained unstrained for a short period at 100 C.In order that valid comparisons can be made on test pieces, a conditioning trea
24、tment is specified so that the measurements are made on test pieces brought close to a condition of zero strain.Electrode systemsCertain types of electrode, when applied to these rubbers, have a contact resistance which can be many thousands of times greater than the intrinsic resistance of the test
25、 piece. Dry contacts under light pressure or point contacts are particularly poor.The definition of a suitable electrode system is therefore an important part of this International Standard and, in order to satisfy the various practical requirements for tests on laboratory-prepared test pieces, seve
26、ral electrode systems have been selected and are described in Clauses 3, 4 and 5.ISO 1853:2011(E) ISO 2011 All rights reserved vBS ISO 1853:2011BS ISO 1853:2011INTERNATIONAL STANDARD ISO 1853:2011(E)Conducting and dissipative rubbers, vulcanized or thermoplastic Measurement of resistivityWARNING Per
27、sons using this International Standard should be familiar with normal laboratory practice. This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure co
28、mpliance with any national regulatory conditions.1 ScopeThis International Standard specifies the requirements for the laboratory testing of the volume resistivity of specially prepared test pieces of vulcanized or thermoplastic rubber compounds rendered conducting or dissipative by the inclusion of
29、 carbon black or ionizable materials. The tests are suitable for materials with a resistivity of less than about 108m.Method 1 is the preferred method when test pieces with bonded electrodes are not available.Method 2 is the preferred method when test pieces are moulded with the inclusion of bonded
30、electrodes.Method 3 may be used if the apparatus for method 1 or 2 is not available, but it has lower accuracy.If a reference to this International Standard is made without specifying the method, then method 1 shall be used.2 Normative referenceThe following referenced documents are indispensable fo
31、r the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 23529, Rubber General procedures for preparing and conditioning test pieces for physical test methods
32、3 Method 13.1 Apparatus and materialsSee Figure 1 for a schematic diagram of the test circuit.3.1.1 Current source: A source of direct current which has a minimum resistance to earth of 1012 and which will not cause a dissipation of power greater than 0,1 W within the test piece.3.1.2 Means of measu
33、ring the current to an accuracy of 5 %.NOTE Very small currents can be computed from measurement of the voltage drop across a known resistance using an electrometer (3.1.5).3.1.3 Test piece holder and current electrodes, comprising a polystyrene strip of about 10 mm thickness to which the current el
34、ectrodes are fixed (see Figure 1). The current electrodes shall be of clean metal approximately 5 mm long and running across the full width of the test piece, and be held in place by suitable clamps or grips.The distance between the current electrodes shall be at least 75 mm, and the resistance betw
35、een them shall be greater than 1012.A minimum of three test piece holders shall be available. ISO 2011 All rights reserved 1BS ISO 1853:2011Key1 test piece2 current electrode3 sheet of insulating material resistivity at least 10134 electrometer5 potentiometric electrode6 adjustable direct-current vo
36、ltageFigure 1 Schematic diagram of test circuit3.1.4 Potentiometric electrodes, constructed so that they exert a contacting force of approximately 0,65 N for 10 mm wide test pieces or 1,3 N for 20 mm wide test pieces (see Figure 2). The resistance between the potentiometric electrodes shall be great
37、er than 1012.3.1.5 Electrometer, having an input resistance greater than 1011. References for such instruments are given in Annex A.3.1.6 Sheet of insulating material, having a resistivity greater than 1013m.3.1.7 Oven, capable of being controlled at a temperature of (70 2) C.3.2 Test pieceEach test
38、 piece shall be a strip, (10 0,5) mm or (20 0,5) mm wide, of vulcanized or thermoplastic rubber at least 70 mm long and normally 2 mm, 4 mm or 6,3 mm thick, with a tolerance of uniformity of thickness of 5 %.For comparison purposes, test pieces of the same size shall be used.The test piece can be cu
39、t out with a knife or die, but care shall be taken to minimize distortion as this will affect the resistance values.The surfaces of the test piece shall be clean; if necessary, they can be cleaned by rubbing with Fullers earth (aluminium magnesium silicate) and water, washing with distilled water an
40、d allowing to dry. The surfaces shall not be buffed or abraded.Do not clean the test pieces with organic materials that would attack or swell the rubber.ISO 1853:2011(E)2 ISO 2011 All rights reservedBS ISO 1853:2011Dimensions in millimetresKey1 polystyrene strip2 stainless steelaTest piece width + a
41、t least 10 mm.b10 mm to 20 mm measured to 2 %.Figure 2 Potentiometric electrodes3.3 Number of test piecesThree test pieces of equal size shall be prepared and tested.3.4 ProcedureAllow the test piece to rest for not less than 16 h after vulcanization or moulding, in accordance with ISO 23529.Immedia
42、tely prior to the commencement of the test, place the test piece on the test piece holder and clamp the current electrodes to its ends.Without removing it from the test piece holder, heat the test piece in the oven for 2 h 15 min at a temperature of (70 2) C and then condition for not less than 16 h
43、 at a standard laboratory temperature and humidity in accordance with ISO 23529. Place the two potentiometric electrodes in position with a distance of 10 mm to 20 mm between them, ensuring that the knife edges are at right angles to the current flow and that neither is nearer than 20 mm to a curren
44、t electrode. Measure the distance between the potentiometric electrodes to an accuracy of 2 %.Apply the current and, after the current has been passing for 1 min, determine the steady potential between the potentiometric electrodes, using the electrometer at the same standard temperature and humidit
45、y as was used to condition the test piece.Repeat the measuring procedure twice more on the same test piece, moving the potentiometric electrodes each time to obtain measurements over lengths of the test piece evenly distributed between the current electrodes.Similarly, test the other two test pieces
46、.ISO 1853:2011(E) ISO 2011 All rights reserved 3BS ISO 1853:20113.5 Expression of resultsAverage the three measurements of resistance for each test piece and calculate the resistivity, , in m, as follows: = V w tl IwhereV is the measured potential, in V;w is the width of the test piece, in m;t is th
47、e thickness of the test piece, in m;l is the distance between the potentiometer electrodes, in m;I is measured current, in A.Report the median value of the resistivities of the three test pieces.3.6 Test reportThe test report shall include the following information:a) sample details:1) a full descri
48、ption of the sample and its origin,2) the method of preparation of the test piece from the sample, for example moulded or cut;b) test method:1) a full reference to the test method used, i.e. ISO 1853:2011, method 1,2) the dimensions of the test piece used;c) test details:1) the time, temperature and
49、 humidity of conditioning prior to the test,2) the voltage applied to the current electrodes,3) the current through the test piece,4) details of any procedures not specified in this International Standard;d) test results:1) the median value of the resistivities of the three test pieces,2) the individual average resistivity value for each test piece, if required;e) the date of the test.4 Method 24.1 Apparatus and materials4.1.1 Brass electrodes, with dimensions as given in Table 1 and Figure 3. Th
