Measurement device using a beat signal between two oscillating circuits

摘要

Measuring device (20) comprising a unit of the sensor and a control unit (22) separated electrically by a partition (23). The unit of the sensor comprises a first oscillating circuit formed of a first coil (25a) electrically connected to a first capacitive sensor (21a) and a second oscillating circuit formed by a reference capacitor (21) which is electrically connected to a second coil. The control unit (22) comprises a third coil (26) is coupled by induction to the first coil (25a) and to the second coil (35a). The third coil determines the beat frequency of the beat signal injected into the third induction coil (26) on the basis of the first and second oscillating circuits in order to form the measurement signal which will be provided.