Electrical – Diy capacitive level measures sensor


I am trying to build an capacitive level measures sensor. I am new to this and if anyone can guide me in the right direction for a breakout card and so on.


  1. The size of measure level are between 100-500ml.
  2. And level of sensitivity 0.5ml.
  3. Out level signal needs to be converted to an analog signal from low to high.

I like this project

My idea is to get the signal from this in though the microphone line-in and measure the volume strength and then code so I get the volume amount.

Best Answer

The type of liquid to be measured is important, since capacitance depends on the dielectric constant. Water, being a polar molecule, has a very high value and is easy. Something like octane much less so.

Assuming water, you need a large area for the electrodes to give you a decent capacitance especially when the fluid level is low. Maybe use concentric metal pipes, perhaps stainless steel since water is quite corrosive. Then treat the whole thing as an input capacitor to your microphone, feeding it with a high frequency signal, maybe 10kHz for starters and see whether you can pick it up.

Most of this is experimental physics, with the emphasis on "experiment"