Object displacement detector for e.g. museum piece - uses piezoelectric element which has damped pendulum movement

摘要

The object movement detector includes a pendulum type displacement system associated with an amplitude limiting damping element. An amplifier is provided for signals generated by the detector. The pendulum part of the detector has a piezoelectric element(1), one end of which is fixed. The free end of the piezoelectric element is associated with a fixed inertial mass. The inertial mass is amplitude damped for pendulum displacements by a honeycombed plastic material crown(4) surrounding it. The exterior surface of the plastic material crown is in permanent contact with the interior surface of a tubular body(9) which forms the rigid and protective support for the detector.