11
on testing current. Fourier transform is adopted for filtering out
interference so as to separate the fundamental wave of signal,
make vector operations of the standard current and specimen
current, and calculate the capacitance and the tgδ. After repeated
measurements, the intermediate result would be selected. After the
completion of measurement, the measurement circuit would send
step-down instruction to make the voltage of variable frequency
power to be reduced to 0 slowly.
III. Main technical parameters
1. High voltage output: 0.5~10kV
Increasing by 500V for each level, a total of
20 levels, capacity: 1500VA
2. Accuracy: tgδ: ± (reading *1.5% +0.06%)
Cx: ± (reading * 1.5% +5 PF)
3. Resolution: tgδ: 0.01%
Cx: 1pF
4. Measuring range: 0.01% <tgδ <100%
3PF <Cx <60000PF
When it is 10KV, Cx ≤ 30000PF
When it is 5KV, Cx ≤ 60000PF
5. Power supply: AC 220V ± 10%
50 ± 1Hz
6. Measuring method: a.working frequency:50Hz
