IEC 61340-2-3:2000 pdf download

IEC 61340-2-3:2000 pdf download.Electrostatics -Part 2-3:Methods of test for determining the resistanceand resistivity of solid planar materials usedto avoid electrostatic charge accumulation.
3 Definitions
For the purpose of this part of IEC 61340. the following definitions apply:
volume resistance\
the ratio of a d.c. voltage CV) applied between two electrodes placed on two (opposite) surfaces of a specimen and the steady•state current (A) between the electrodes
3.2
volume resistivity (ram)
the ratio of a d.c. field strength (Vim) and the steady-state current density (A/rn2) within the material. In practice, it is equivalent to the volume resistance of a cube with unit length, having the electrodes at two opposite surfaces
NOTE Votulne veslst,vly is not an appropriate characteristic br mateiaIs that are electrically Inhomogeneous.
3.3
surface resistance (Ca)
the ratio of a d.c voltage (V) applied between two electrodes on a surface of a specimen and the current (A) between the electrodes
3.4
surface resistivity (Q)
the surface resistivity is equivalent to the surface resistance of a square area, having the electrodes at two opposile sides
NOTE miSt unit of surface resistivity (0)1 $onlitim.s r,I,rr.d to as 0’sq fotims pit squar.I.
3.5
measuring electrode
a conductor of defined shape, size and configuration being in contact with the specimen to be
measured
4 CondItioning and test environment
The electrostatic behaviour of materials is influenced by environmental conditions, such as relative humidity and temperature.
For this reason, measurements shall be performed under controlled conditions. The selection of the appropriate conditions for testing shall be decided according to the type of material (product specification) and the intended application, based on the most severe conditions (e.g. lowest humidity) expected to occur during usage. Specimens shall be conditioned and measured in the same climate, if not specified differently.
Preconditioning can be necessary in order to eliminate the effects of stress appearing after the moulding process of some plastic materials or as a drying treatment before the test procedure starts. The preconditioning shall normally be handled in a different environmenL
Adequate devices are a desiccator in an oven or a climate chamber preferably equipped with
forced circulation and interchange of air. Additional guidance may be taken from IEC 60212
and IEC 60260.
5 Selection of test method
The following procedure shall be used to select the test method:
a) If the range of electrical resistance of a material to be tested is known, then use the relevant clause where appropriate standards are listed or methods described;
b) for a material of initially unknown resistivity, start the measurements by using methods br conductive materials according to clause 6.
If the measurement is not possible or the obtained result exceeds the given range for the application of the test method, it shall be regarded as being inadequate and the result shall not be taken into account, The measurement shall be repeated according to clause 8 for static- dissipative materials, It the situation described above occurs again, the measurement shall be repeated according to clause 7 for insulating materials.
6 Resistance measurements of solid conductive materials
The resistance of solid conductive materials (non-metals) shall be measured in accordance with ISO 3915 for plastics or ISO 1853 for rubbers.
For highly conductive materials, the contact resistances necessitate the method of a quadrupole measurement in order to avoid a non-linear potential distribution over the specimen. The most important parameter is the current infected through the specimen or, even more precisely, the dissipated power In order to avoid significantly heating the material.
7 Resistance measurements of solid insulating materials
The resistance of solid insulating materials shall be measured in accordance with IEC 60093. IEC 60167 for plastics or ISO 2951 for rubbers.
For highly insulating materials, the resistance along the surface can be much lower compared to the resistance through the material due to the effect of adsorbed contaminants such as water. Furthermore, there can exist a non-linear functional correlation between the applied voltage and the conducted current. Thus, the surface and volume resistance of solid insulating materials are conventionally measured under specified conditions (generally 500 V and 1 mm time of electrification) with guarded electrodes.
Liquid, painted or sprayed contact electrodes could modify the behaviour of the specimen under test and shall not be applied. The use of conductive rubber as contact material is strongly recommended instead.