Conductive measuring principle
The fill level of a liquid is detected by measuring its conductivity using a conductive probe. The probe is fixed at the required measurement height in the container and is supplied with a minimal current. Once the probe comes into contact with the liquid the conductive circuit is completed via the metal container wall and a signal is sent out.
By using alternating current, possible corrosion of the probe and possible electrochemical reactions are avoided. To ensure reliable measurement in rippling liquids an adjustable signal time delay has been built in.
Probes with one electrode can be used in metal containers as full or empty detectors, with two electrodes as a full and empty detector in metal containers. With three electrodes it is possible to be used as a full and empty detector in non metal containers.