The Multipoint Switch is based on the conductivity principle and can be applied to liquids with conductivity higher than 10 μS/cm.

The probes has to be immersed into the tank for detecting the level. The probe length should be in accordance with the level to be detected. Filling liquid in the tank will change the electrical conductivity between the reference probe and probes. The established connection will be converted and will activate a relay providing for output.