Patent ID: 8596134

Claim:
A bolt tension monitoring system, comprising: a hollow housing having opposed upper and lower ends, the lower end defining a recess adapted for being retained on a head of a bolt; a force transducer having opposed upper and lower faces, the upper face being adapted for providing a bearing surface for the head of the bolt, the force transducer being positioned between the head of the bolt and a workpiece surface in which the bolt is fastened, the force transducer converting tension between the head of the bolt and the workpiece surface into a calibrated voltage, wherein the tension is continuously measured by the force transducer; a controller circuit electrically connected to the force transducer for calculating a difference between the calibrated voltage corresponding to currently measured tension between the head of the bolt and the workpiece surface and the calibrated voltage corresponding to an initial tension measured when the bolt is installed in the workpiece; and a transponder circuit for automatically transmitting an alert signal when the difference exceeds a pre-defined threshold value, the transponder circuit being electrically connected to the controller circuit and mounted in the housing.