The displacement transducers work according to the principle of the differential choke (inductive half bridges). They consist of two coils which are encapsulated in a Mu metal cylinder in a sealed and vibration-proof manner. A Mu-metal plunger causes an opposite induction change in the two coils when displaced by the hollow coil body. The displacement transducers are designed for an oscillator frequency of 10 kHz. Power supply and signal conditioning are provided by external module modules.