In a plasma application (Helium or Argon Plasma), we would like to measure the current. The voltage is around 10kV AC and modulated with a function generator.
Currently we only have one of those rings that you put around the cable, but I read that those only work for high-ish amperage >1A. While using this device, we get an output of around 12mV peak to peak, put I think that this is very inaccurate.
Is there any cheap way (we are students) of measuring the current more precisely? Preferably without killing equipment and/or operators 🙂
For a low voltage circuit I would use a high accuracy resistor and measure the voltage drop across, but I think that this is too dangerous in such high-voltage applications.
Best Answer
You could use a transformer to multiply up the current.
The image shows a current transformer working in the normal way for measuring very high currents. The measured current will be 1/N times that in the red cable. Basically you want to do the opposite.
Get a large iron ring, and loop your cable through it 10x. Then loop another small wire through the ring and measure the current in that.