Electrical level measurement transducers which use the displacement principle must be re-calibrated each time the fluid density is changed.
The price of a magnetically controlled level indicator with integral electrical measurement transducer is considerably lower than level measurement transducers.
The reed chain with an R/I measurement transducer can be changed without interrupting operation. The measurement chamber is hermetically sealed - there is no contact between the fluid chamber and the reed chain.
With the microprocessor-controlled level indicator unit type 420, the level can be displayed direct in any arbitrary physical measurement unit.
The indicator has a curve calculator with which nonlinear tank contents can be displayed direct in cubic meters.