Sensor for determining and monitoring tension in fastening, especially screw; has piezoelectric plastics bonded to it, with circuitry determining potential developed under stress

摘要

A sensor (2) measures deformation of the screw (10). It comprises a piezoelectric plastics element bonded to the screw. This undergoes resilient deformation in response to applied force. A circuit detects the resultant electrical potential, which is a function of deformation. An Independent claim is included for the corresponding method.