11
Introduction
5.3
DTS1
dielectric test sample box
The
DTS1
dielectric test sample box is an accessory for demonstrating and testing the functionality of
SPECTANO 100
without a sample test cell. The
DTS1
is a demo box containing two samples: a high-
precision, low-loss 1 nF capacitor and a RC circuit simulating a dielectric sample with losses. The
main application areas of the
DTS1
are in training and demonstration purposes but it can also be
used for detecting errors in a cable setup.
5.4
Frequency domain spectroscopy (FDS)
By using the frequency domain spectroscopy (FDS), the dielectric properties of the solid or liquid material
under test are measured by frequency sweep (5 µHz to 5 kHz). The FDS allows fast measurements at
high frequencies but requires long measurement times at lower frequencies.
5.5
Polarization current method (PDC)
In the polarization current (PDC) method, a DC voltage is applied to the device under test for a specific
time and the polarization current is measured. From the polarization current, the dielectric response is
evaluated, and the dielectric frequency characteristic is calculated using Fourier transformation. The
PDC method is faster than the FDS at very low frequencies, but the upper frequency is limited due to
the finite rise time of the DC pulse. The test frequency range for the PDC method is 20 µHz to 100 mHz.
5.6
Combined mode (FDS and PDC)
SPECTANO 100
combines the PDC with the FDS principle and thus significantly reduces the testing
time to exclusive frequency domain measurements. PDC measurements can be accomplished in a short
time but are limited to low frequencies while FDS measurements are feasible for high frequencies but
take very long at low frequencies. It combines the advantages of both principles. It measures data in the
time domain for frequencies below 100 mHz. This reduces the measurement time up to 75% compared to
exclusive FDS measurements. For example, a FDS measurement from 1 kHz to 100 µHz will take 11
hours,
SPECTANO 100
will acquire this data in less than 3 hours using the combined FDS and PDC
measurement. The maximum test frequency range for the combined mode is 20 µHz to 5 kHz.
Test duration
Frequency band
Figure 5-1
Comparison of measurement methods
FDS
PDC
Combined
