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SPECTANO 100 User Manual
When measuring the dielectric properties of solid materials without guarding, the measurement is
influenced by stray capacitances at the edge c
Figure 13-4
The influence of the edge capacitances is smallest for the case of electrodes extending to the edge of
the specimen (electrode diameter = sample diameter) and largest for unequal electrodes. Thus, the
correction of the edge capacitance c
The international standards IEC 60250-1969, D150-11, D150-18 (AC methods) describe how the
measurement accuracy can be improved using edge capacitance correction calculations.
The edge correction calculations do not include the correction of the stray capacitances of the test cell or
between the leads and to ground influence the measurement accuracy. Thus, instead of the correction
calculation we recommend to
Perform a standardized air reference measurement using the SPECTANO Analyzer Suite
•
Activate the correction to display the corrected capacitance and relative permittivity ε
•
For more information about the air reference correction and its equations read chapter 10.4
"Perform reference measurements".
Liquid insulation materials
Edge capacitances are not a problem for the analysis of liquid insulating materials using a Disk electrode
arrangement with Guard ring. Nevertheless, stray capacitances of the test cell or between the leads and
to ground are influencing the measurement accuracy. We recommend performing the air reference
correction steps described in the solid insulating material analysis chapter "Solid insulating materials".
80
of the solid test material, as shown in Figure 13-3.
e
Measurement circuit, un-guarded electrode
depends on the electrode and sample size combination.
e
values.
r
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