Device and a method for non-contacting sensing of the rotational state of a rotor

摘要

A device and a method for non-contacting sensing of the rotational state of a rotor (10). The rotor has a surface divided into an electrically conductive part (1e) and a nonconductive part (1f). Three electric coils (2a, 2b, 2c) are each included in a respective parallel resonant circuit and are applied close to and with their longitudinal axes oriented towards the rotational path of the electrically conductive part of the rotor. The resonant oscillations are damped depending on the rotational position of the rotor. The rotational state is evaluated with an electronic circuit In a liquid-flow meter, the coils may be applied in the dry part of the meter.