Dynamic sensor for measurement device

A measurement device including an oscillating sensor device, particularly for a proximity sensor, for sensing a dynamic change of attenuation caused by a measurable physical effect, comprising:

• an oscillator including a resonance circuit and an amplifier fed back to the resonance circuit and configured to maintain oscillation of the oscillator wherein the amplifier comprises a non-linear gain characteristics defining an operating point at a preset amplitude of oscillation, and
• a control unit configured to control an open loop gain of the oscillator, wherein:
• the open loop gain is defined as a gain resulting from a ratio of a voltage amplitude of the oscillation at the resonance circuit and a variable amplitude of an amplifier input for an open loop condition;
• the control unit is configured to control the open loop gain of the oscillator so that the operating point is set to the preset amplitude of the oscillation;
• a dynamic of adapting the open loop gain is lower than a dynamic of change of attenuation due to an object to be detected;
• and
• the control unit comprises:
• an amplitude determination unit for determining a current amplitude value of the oscillation amplitude and a control deviation unit for determining an amplitude deviation between the preset amplitude and the current amplitude value;
• and
• an analyzing unit configured to receive the amplitude deviation and derive a sensor signal therefrom.