21
Setup improvements
2. Perform the air reference measurement(s) by using
SPECTANO Analyzer Suite
as described
in 10.4 "Perform reference measurements" .
Note:
We recommend adjusting the air space height equal to the thickness of the sample probe under
test. If it is not possible, we recommend performing two air reference measurements with different air
spaces. Preferably, make a first measurement with the spacer that is higher than the sample thickness
and a second measurement with the spacer that is lower than the sample thickness.
For more information on sample dimension or test setup improvement, see our application notes
8.2
Electrodes for solid dielectric material analysis
The used electrodes should be parallel and must have a proper contact to the material sample to ensure
a good contact and reliable measurement results. Air inclusions should be avoided.
“Soft” material sample
In this case, a proper material contact with electrodes may not be an issue but the pressure from the
electrodes may deform the material sample, what can possibly change the measured permittivity.
“Rigid” material sample
In this case, a deformation of the sample under pressure may not be significant but as shown in the
following figure, areas with no sufficient contact between electrodes and material sample surface will
prevent a homogeneous current flow through the sample. This leads to measurement results which do
not represent the properties of the material volume.
Figure 8-3
Bad contact between material sample surface and electrodes
1
1. This image refers to the IEEE Transactions on Dielectrics and Electrical Insulation Vol. 20, No. 3; June 2013, paper “Enhanced
Accuracy in Dielectric Response Material Characterization by Air Reference Method” from Xiangdong Xu, Tord Bengtsson,
Jörgen Blennow and Stanislaw M. Gubanski.
Material
sample
Electrodes
