A float moves along a vertical guide tube. The permanent magnet fixed in the float switches the contacts of a reed contact resistor chain. This resistor chain acts as a voltage divider and provides the voltage values corresponding to the medium level. The resolution is dependent on the number of contacts used. The measurement is independent of the electrical properties of the filling material, as well as the pressure, temperature and density.
The permanent magnet located inside the float actuates the reed switches inside the guide tube. When actuated, these reed switches switch between a series of resistors in the guide tube, thus changing the total resistance nearly continuously, depending on the resolution.
In addition to the 3-wire potentiometer circuit, 4 mA…20 mA and 2-wire PLM signals are also available as electrical outputs.