ISO 14309:2019 pdf download

ISO 14309:2019 pdf download.Rubber, vulcanized or thermoplastic — Determination of volume and/or surface resistivity
1 Scope
This document specifies a method for 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 10 1 Ω⋅m to 10 17 Ω⋅m.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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 1382, Rubber — Vocabulary
ISO 18899:2013, Rubber — Guide to the calibration of test equipment
ISO 23529, Rubber — General procedures for preparing and conditioning test pieces for physical test methods
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1382 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.5 guarded-electrode system
electrode 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 than the test voltage, and of stray conductances Note 1 to entry: 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 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 element 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 5.3.2 of IEC 62631-3-1:2016 for more details).
4 Principle
The volume and surface resistances 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.