Solid insulating materials - Dielectric and resistive properties - Part 1: General
1 Scope
This part of GB/T 31838 specified the general aspects related to the determination of dielectric and resistive properties of solid electrical insulating materials.
2 Normative references
The following referenced documents are indispensable for 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.
GB/T 1409-2006 Recommended methods for the determination of the permittivity and dielectric dissipation factor of electrical insulating materials at power, audio and radio frequencies including meter wavelengths (IEC 60250:1969, IDT)
GB/T 1410-2006 Methods of test for volume resistivity and surface resistivity of solid electrical insulating materials (IEC 60093:1980, IDT)
GB/T 10064-2006 Methods of test for the determination of the insulation resistance of solid insulating materials (IEC 60167:1964, IDT)
GB/T 10581-2006 Method of test for electrical resistance and resistivity of insulating materials at elevated temperatures (IEC 60345:1971, IDT)
IEC 60377-1:1973 Recommended methods for the determination of the dielectric properties of insulating materials at frequencies above 300MHz - Part 1: General
IEC 60377-2:1977 Recommended methods for the determination of the dielectric properties of insulating materials at frequencies above 300MHz - Part 2: Resonance methods
IEC 60050-212 International electrotechnical vocabulary - Part 212: Electrical insulating solids, liquids and gases
ISO 291 Plastics - Standard atmospheres for conditioning and testing
ISO 558 Conditioning and testing - Standard atmospheres - Definitions
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 General definitions
3.1.1
electrical insulating material
solid material with negligibly low electric conductivity, used to separate conducting parts at different electrical potentials
Note: In English, the term "electrical insulating material" is sometimes used in a broader sense to also designate insulating liquids and gases. Insulating liquids are covered by IEC 60247.
3.2 Definitions for resistive properties
The resistive properties of an insulating material are those comprehensive materials whose behaviour can be measured with a DC in a time domain.
3.2.1
insulation resistance
resistance under specified conditions between two conductive bodies separated by the insulating material
Note: Insulation resistance includes parts of volume resistivity and surface resistivity with respect to a given geometric shape of the test specimen.
3.2.2
volume resistance
quotient of a direct voltage applied between two electrodes in contact with an insulating medium and the current through it at a given duration of voltage application
Note: Within this definition, current along the surface is excluded and possible polarization phenomena at the electrodes are neglected.
3.2.3
volume resistivity
quotient of a DC electric field strength and the current density within an insulating medium at a given time of voltage application
Note 1: According to IEC 60050-212, "conductivity" is defined as "the scalar or matrix quantity whose product by the electric field strength is the conduction current density" and "resistivity" as "the reciprocal of the conductivity". The volume resistivity is an average of this quantity over possible heterogeneities in the volume incorporated in the measurement, and includes the effect of possible polarization phenomena at the electrodes.
Note 2: Usually, volume resistivity in practice is taken as the volume resistance reduced to a cubical unit volume.
3.2.4
surface resistance
that part of the insulation resistance which is due to conduction along the surface
Note: The surface current generally depends strongly on the time of voltage application and often varies in an erratic manner.
Foreword i
Introduction iii
1 Scope
2 Normative references
3 Terms and definitions
4 Factors influencing properties of electrical insulating materials
5 Electrode systems
6 Test procedures
Bibliography
