1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 14309:2011Rubber, vulcanized orthermoplastic Determinationof volume and/or surfaceresistivityBS ISO 14309:2011 BRITISH STANDARDNational forewordThis British Standard is th
2、e UK implementation of ISO 14309:2011.It supersedes BS 903-C1:1991, also numbered as BS 2782-2:Method231A:1991, and BS 903-C2:1982, also numbered as BS 2782-2:Method230A:1982, which are withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/22, Physical testing of
3、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 necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 69661 9ICS 83.060Compliance with a
4、British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 2011.Amendments issued since publicationDate Text affectedBS ISO 14309:2011Rubber, vulcanized or thermoplastic Determina
5、tion of volume and/or surface resistivityCaoutchouc vulcanis ou thermoplastique Dtermination de la rsistivit transversale et/ou superficielle ISO 2011Reference numberISO 14309:2011(E)First edition2011-09-15ISO14309INTERNATIONAL STANDARDBS ISO 14309:2011ISO 14309:2011(E)COPYRIGHT PROTECTED DOCUMENT I
6、SO 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 mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the
7、 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.orgPublished in Switzerlandii ISO 2011 All rights reservedBS ISO 14309:2011ISO 14309:2011(E)Contents PageForeword ivIntroduction v1 Scope 12 No
8、rmative references .13 Terms and definitions .14 Principle .25 Apparatus 26 Calibration .57 Test pieces 57.1 Form of test piece .57.2 Number of test pieces 68 Conditioning .69 Test conditions .69.1 Temperature and humidity 69.2 Applied voltage 610 Test procedure .611 Expression of results .711.1 Vol
9、ume resistivity 711.2 Surface resistivity .712 Test report .8Annex A (informative) Electrode materials 9Annex B (informative) Suitable range of test conditions .10Annex C (normative) Calibration schedule12Bibliography .14 ISO 2011 All rights reserved iiiBS ISO 14309:2011ForewordISO (the Internationa
10、l Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been es
11、tablished 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 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardi
12、zation.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 Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for votin
13、g. 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 of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such p
14、atent rights.ISO 14309 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 2, Testing and analysis.ISO 14309:2011(E)iv ISO 2011 All rights reservedBS ISO 14309:2011IntroductionRubber materials are widely used in many industries, either as the major material or
15、forming a part of the product, because of their unique physical properties which can be tailored by compounding to match the particular requirements of the product specification. Although rubbers are generally regarded as insulating materials, they can be made electrically conductive or dissipative
16、by compounding with a certain amount of carbon black or ionizable ingredients. Hence, the range of electrical resistance to be measured is very wide. It is difficult, however, to obtain high accuracy for measurements in the high-resistance range due to a number of factors.In this International Stand
17、ard, the guarded-electrode system is used to determine the resistivity of rubber test pieces since it is considered a good compromise between minimizing the errors by shunting away stray currents and using more unwieldy measurement instruments (see also IEC 60093).ISO 1853, on the other hand, covers
18、 rubber materials with medium to low resistance, i.e. resistivities of 1010m or below. It specifies three methods for determining volume resistivity which minimize or eliminate contact resistance.The methods specified in this International Standard were originally designed for the determination of b
19、oth surface and volume resistivity of insulating rubber materials, but their use can be extended to cover the range from high to low resistivity.It is known that the test results are sensitive to the test conditions, such as temperature and humidity, and to heat and strain history.ISO 14309:2011(E)
20、ISO 2011 All rights reserved vBS ISO 14309:2011BS ISO 14309:2011INTERNATIONAL STANDARD ISO 14309:2011(E)Rubber, vulcanized or thermoplastic Determination of volume and/or surface resistivityWARNING Persons using this International Standard should be familiar with normal laboratory practice. This sta
21、ndard 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 compliance with any national regulatory conditions.IMPORTANT Certain procedures specified in this Int
22、ernational Standard might involve the use or generation of substances, or the generation of waste, that could constitute a local environmental hazard. Reference should be made to appropriate documentation on safe handling and disposal after use.1 ScopeThis International Standard specifies a method f
23、or the determination of the volume and the surface resistivity of vulcanized or thermoplastic rubbers. The method can be applied to materials with a resistivity from 101m to 1017m.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dat
24、ed references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 1382, Rubber VocabularyISO 18899:2004, Rubber Guide to the calibration of test equipmentISO 23529, Rubber General procedures for preparing and c
25、onditioning test pieces for physical test methods3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 1382 and the following apply.3.1volume resistanceRvquotient of a direct-current voltage applied between two electrodes in contact with opposite faces of a
26、 test piece and the current between the electrodes, excluding current along the surfaceNOTE It is expressed in ohms ().3.2surface resistanceRsquotient of a direct-current voltage applied between two electrodes on the same surface of a test piece and the current between the electrodesNOTE It is expre
27、ssed in ohms (). ISO 2011 All rights reserved 1BS ISO 14309:20113.3volume resistivityvmeasured volume resistance calculated to apply to a cube of unit sideNOTE It is expressed in ohm metres (m).3.4surface resistivitysmeasured surface resistance calculated to apply to a squareNOTE It is expressed in
28、ohms () and the size of the square is immaterial.3.5guarded-electrode systemelectrode system composed of three electrodes, a guard, and a guarded and an unguarded electrode to reduce measurement errors by protecting the current-measuring electrode from the interfering influences of voltages other th
29、an the test voltage, and of stray conductancesNOTE Guarding depends on interposing, in all critical insulated parts, guard electrodes which intercept all stray currents that might otherwise cause errors. The guard electrodes are connected together, constituting the guard system and forming with the
30、measurement terminals a three-terminal network. When suitable connections are made, stray currents from spurious external voltages are shunted away from the measurement circuit by the guard system, the insulation resistance from either measurement terminal to the guard system shunts a circuit elemen
31、t which should be of very much lower resistance, and the specimen resistance constitutes the only direct path between the measurement terminals. By this technique, the probability of error is considerably reduced (see 5.3 of IEC 60093:1980 for more details).4 PrincipleThe volume and surface resistan
32、ces of a rubber test piece are determined, using a suitable arrangement of electrodes, from the current flowing when a voltage is applied. The volume and surface resistivities are calculated from the measured resistances, which include the contact resistance.5 ApparatusThe test equipment consists of
33、 a power supply, current-measuring equipment and electrodes, as follows:5.1 Stabilized direct-current power supply, capable of applying a voltage of 1 V to 1 000 V to the test piece.5.2 Voltmeter, capable of measuring the applied voltage with an accuracy of 2 %.5.3 Ammeter or other current-measuring
34、 device, capable of measuring a current of 0,01 pA to 100 mA, depending on the resistivity of the test piece to be measured. The accuracy of the current-measuring device shall be better than 5 %.5.4 Electrodes, as follows:5.4.1 Guarded-electrode systemThree electrodes shall be applied to the test pi
35、ece: a main electrode (circular); a ring electrode (annular); a n opposed electrode (circular).ISO 14309:2011(E)2 ISO 2011 All rights reservedBS ISO 14309:20115.4.2 Shapes and dimensions of electrodesThe main (smallest) electrode is circular and is surrounded by the ring electrode. The third electro
36、de is circular and placed on the opposite side of the test piece to the main electrode. The arrangement of the electrodes is shown schematically in Figure 1. The dimensions of the electrodes shall comply with following requirements: T he diameter D1of the main electrode shall be at least ten times t
37、he test piece thickness h. T he gap g between the main electrode and the ring electrode shall be uniform in width. For the measurement of volume resistivity, it should preferably be as narrow as possible so that surface leakage does not cause any error in the measurement. In practice, it is usually
38、1 mm or larger. For the measurement of surface resistivity, it shall be at least twice the test piece thickness so that the effect of the volume resistance can be ignored. T he width of the ring electrode shall be greater than the test piece thickness h. T he diameter D4of the opposed electrode shal
39、l be greater than the outer diameter D3of the ring electrode.A typical example is as follows:D1(50 0,5) mmD2(70 0,5) mmD3(80 0,5) mmD4(83 2) mmgD3hD2D4D1Figure 1 Arrangement of electrodesISO 14309:2011(E) ISO 2011 All rights reserved 3BS ISO 14309:20115.4.3 Electrode materialsElectrodes shall be of
40、a conducting material capable of being intimately applied to the test piece. If they are applied before conditioning, the material shall be moisture-permeable. Electrodes other than of rigid metal shall be supplemented by rigid metal backing plates.NOTE Suitable electrode materials are considered in
41、 Annex A.5.4.4 Electrical circuitsSuitable circuits for testing are shown in Figures 2 and 3.A1234578 61091211Key1 guarded electrode (main electrode)2 guard electrode (ring electrode)3 test piece4 unguarded electrode (opposed electrode)5 direct-current supply6 switch7 connection for short-circuiting
42、 electrodes (to discharge test piece)8 connection for measurement circuit9 ammeter10 earth11 measurement current12 guard currentFigure 2 Circuit configuration for volume resistivityISO 14309:2011(E)4 ISO 2011 All rights reservedBS ISO 14309:2011A123457861091211Key1 guarded electrode (main electrode)
43、2 unguarded electrode (ring electrode)3 test piece4 guard electrode (opposed electrode)5 direct-current supply6 switch7 connection for short-circuiting electrodes (to discharge test piece)8 connection for measurement circuit9 ammeter10 earth11 measurement current12 guard currentFigure 3 Circuit conf
44、iguration for surface resistivity6 CalibrationThe requirements for calibration of the test apparatus are given in Annex C.7 Test pieces7.1 Form of test pieceThe test piece shall be a flat, smooth sheet of sufficient size that the annular electrode does not reach its edges. The surfaces of the sheet
45、shall not be buffed.The nominal thickness of the test piece shall be in the range 0,5 mm to 5 mm, preferably 1 mm or 2 mm.The thickness of the test piece shall be measured at several points distributed uniformly over the area covered by the main electrode to the nearest 0,01 mm. The average value sh
46、all be used as the test piece thickness. The variation in thickness within a given test piece shall not exceed 10 % of the mean value. Test pieces used for comparative tests shall be, as nearly as practicable, of the same thickness.ISO 14309:2011(E) ISO 2011 All rights reserved 5BS ISO 14309:20117.2
47、 Number of test piecesThree test pieces shall be used.8 ConditioningThe time interval between vulcanization and testing shall be in accordance with ISO 23529.Samples and test pieces shall be stored in accordance with ISO 23529 during the interval between vulcanization and testing.The material shall
48、be conditioned before testing for a minimum of 16 h at standard laboratory temperature and humidity as specified in ISO 23529.Metal foil, liquid and conductive elastomeric electrodes shall be applied after conditioning. This shall be carried out either in the conditioning atmosphere or as soon as po
49、ssible after removal from the conditioning atmosphere. Moisture-permeable electrodes can be applied before conditioning.For a material which has a resistivity of more than 106m, short-circuit two metal plates placed on either side of the test piece during conditioning to avoid the effects of residual charge.9 Test conditions9.1 Temperature and humidityTests are normally performed at a standard laboratory temperature as defined in ISO 23529, although elevated or subnormal temperatures can be used.
