Abstract: The invention concerns an asset monitoring system (10) having a monitoring unit 8 and a plurality of sensors (4) onboard the asset. The sensors (4) are arranged to measure a plurality of operational variables for the asset in use and the monitoring unit (8) is arranged to receive operational variable measurements output from the sensors. The monitoring unit is also arranged to determine a current value of a sensor characteristic (ZA1; ZB1) for each sensor and to compare the current sensor characteristic value with a predetermined sensor characteristic value in order to determine automatically whether a change of one or more sensors has occurred between instances of operation.

Abstract: A dual output accelerometer having first and second output channels, comprises a supporting base, a first transducer comprising a plurality of inter-connected first piezoelectric elements, a second transducer comprising a plurality of inter-connected second piezoelectric elements and a seismic mass. Each of the first piezoelectric elements and the second piezoelectric elements are interleaved with one another, and are co-located with the seismic mass, the co-located first and second piezoelectric elements and the seismic mass being fastened to the supporting base by a rigid mechanical coupling. The interleaved first and second piezoelectric elements provide an improved first output channel to second output channel matching.

Abstract: The invention concerns an asset monitoring system (10) having a monitoring unit 8 and a plurality of sensors (4) onboard the asset. The sensors (4) are arranged to measure a plurality of operational variables for the asset in use and the monitoring unit (8) is arranged to receive operational variable measurements output from the sensors. The monitoring unit is also arranged to determine a current value of a sensor characteristic (ZA1; ZB1) for each sensor and to compare the current sensor characteristic value with a predetermined sensor characteristic value in order to determine automatically whether a change of one or more sensors has occurred between instances of operation.

Abstract: A dual output accelerometer having first and second output channels, comprises a supporting base, a first transducer comprising a plurality of inter-connected first piezoelectric elements, a second transducer comprising a plurality of inter-connected second piezoelectric elements and a seismic mass. Each of the first piezoelectric elements and the second piezoelectric elements are interleaved with one another, and are co-located with the seismic mass, the co-located first and second piezoelectric elements and the seismic mass being fastened to the supporting base by a rigid mechanical coupling. The interleaved first and second piezoelectric elements provide an improved first output channel to second output channel matching.