SIST EN ISO 3915:2000
(Main)Plastics - Measurement of resistivity of conductive plastics (ISO 3915:1981)
Plastics - Measurement of resistivity of conductive plastics (ISO 3915:1981)
Specifies the requirements for the laboratory testing of the resistivity of specially prepared specimens of plastics made conductive by the incorporation of carbon black. The test is suitable for materials having a resistivity of less than 104 Ohm x m. A stable d.c. current is passed between electrodes at the ends of a test piece. A schematic diagram of the test circuit is given. The voltage drop between the two potential electrodes, set on the test piece while the current flows, is measured with an electrometer. The resistance of the portion of the test piece between the potential electrodes is independent of contact resistances.
Kunststoffe - Messung des spezifischen elektrischen Widerstandes von leitfähigen Kunststoffen (ISO 3915:1981)
Plastiques - Mesurage de la résistivité des plastiques conducteurs (ISO 3915:1981)
La présente Norme internationale spécifie les conditions requises pour l'essai en laboratoire de la résistivité transversale 'éprouvettes de plastique spécialement préparées et rendues conductrices par l'addition de noir de carbone. L'essai convient à des matériaux ayant une résistivité inférieure à 10 puissance 6 ohms.cm (10 puissance 4 ohms.m). Le résultat n'est pas la résistivité transversale au sens strict, à cause de la conduction de surface, mais les effets de cette dernière sont généralement négligeables. Le principe de la méthode d'essai à quatre bornes est obligatoire et il faut absolument s'en tenir, dans le cas d'essais de référence, aux recommandations en matière de dimensions d'éprouvette et de modèle d'électrode; cependant, il peut être parfois nécessaire d'effectuer l'essai sur une languette plus large et des électrodes d'un modèle différent.
Polimerni materiali - Merjenje upornosti prevodnih polimernih materialov (ISO 3915:1981)
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Polimerni materiali - Merjenje upornosti prevodnih polimernih materialov (ISO 3915:1981)Kunststoffe - Messung des spezifischen elektrischen Widerstandes von leitfähigen Kunststoffen (ISO 3915:1981)Plastiques - Mesurage de la résistivité des plastiques conducteurs (ISO 3915:1981)Plastics - Measurement of resistivity of conductive plastics (ISO 3915:1981)83.080.01Polimerni materiali na splošnoPlastics in generalICS:Ta slovenski standard je istoveten z:EN ISO 3915:1999SIST EN ISO 3915:2000en01-maj-2000SIST EN ISO 3915:2000SLOVENSKI
STANDARD
SIST EN ISO 3915:2000
SIST EN ISO 3915:2000
SIST EN ISO 3915:2000
International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATlONWlEIKAYHAPO~HAR OPrAHM3AL&lR l-l0 CTAH~APTM3A~MWORGANlSATlON INTERNATIONALE DE NORMALISATION Plastics - Measurement of resistivity of conductive plastics Has tiques - Mesurage de la r&istivitk des plastiques conducteurs First edition - 1981-11-01 U DC 678.5/ .8 : 621.317.332.3 Ref. No. ISO3915-1981 (E) Descriptors : plastics, tests, laboratory tests, measurement, resistivity, test specimen. Price based on 4 pages SIST EN ISO 3915:2000
Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards institutes (IS0 member bodies). The work of developing Inter- national Standards is carried out through IS0 technical committees. Every member body interested in a subject for which a technical committee has been set up 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. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. International Standard IS0 3915 was developed by Technical Committee ISO/TC 61, Plastics, and was circulated to the member bodies in May 1980. It has been approved by the member bodies of the following countries : Australia Germany, F.R. Austria Hungary Belgium India Brazil Ireland Canada Israel China Italy Czechoslovakia Japan Egypt, Arab Rep. of Korea, Rep. of Finland Mexico France Netherlands No member body expressed disapproval of the document 0 International Organization for Standardization, 1981 Philippines Romania South Africa, Rep. of Spain Sweden Switzerland United Kingdom USA USSR Printed in Switzerland SIST EN ISO 3915:2000
INTERNATIONAL STANDARD IS0 39154981 (E) Plastics - Measurement of resistivity of conductive plastics 0 Introduction The method specified in this International Standard is technically similar to that specified for rubber in IS0 1853, Conducting and antistatic rubbers - Measurement of resis- tiviiy. However, it differs from that method in certain details, especially those associated with the greater stiffness of the plastic samples, and in particular in the limitation on specimen width. It takes into account two problems encountered in the measurement of resistivity of conductive plastics, namely the sensitivity of these materials to their temperature-history and strain-history, and the difficulty of making adequate electrical contact with them. The prescribed width of the specimen is mandatory for reference purposes; however, a wider strip may be used, with correspondingly wider electrodes. There is a danger in using a wide strip, if the strip is slightly twisted and at the same time somewhat non-uniform in its resistivity. It is then possible to obtain erroneous results; the potential electrode nearer to the positive current electrode may even be found to be negative with respect to the other potential electrode. Effect of temperature changes and strain on conductive plastics As mentioned above, the resistance of these materials is sensi- tive to their temperature-history and strain-history. The rela- tionships are complex and arise from the kinetic energy and structural configuration of the carbon particles in the polymer. The resistivity may be increased by the effects of strain pro- duced by (or subsequent to) removal from the mould, and a treatment is described for reducing specimens to a constant strain and temperature condition before measurements are car- ried out on them. Specimens are also cut in two perpendicular directions to assess anisotropy. Electrode systems (see 3.3) Certain types of electrode, when applied to these polymers, have a contact resistance which may be many thousand times greater than the intrinsic resistance of the specimen. Dry con- tacts under light pressure or point contacts give very high resistances. However, the present test method eliminates the effects of contact resistances unless these are excessively high. (In such a case, no result, rather than a wrong one, is generally obtained. 1 1 Scope and field of application This International Standard specifies the requirements for the laboratory testing of the resistivity of specially prepared specimens of plastics rendered conductive by the inclusion of carbon black. The test is suitable for materials of resistivity less than 106 Q-cm (104 0m). The result is not strictly a volume resistivity, because of surface conduction, but the effects of the latter are generally negligible. The principle of the four-terminal method of test is mandatory and the recommended specimen size and electrode design must be adhered to for reference purposes, but it may sometimes be necessary to test a wider strip with electrodes of a different construction. 2 Principle A stable dc. current of magnitude (I) is passed between elec- trodes at the two ends of a strip of the material under test. The voltage drop (Au) between two potential electrodes is measured with an electrometer. The resistance of the portion of the strip between the potential electrodes is given by R = AU/I, and is independent of contact resistances. Thus the resistivity may be calculated. 3 Apparatus (see figure 1 for schematic diagram of test circuit) 3.1 Current source : a source of direct current which has a minimum resistance to earth of
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.