The Maihak Shaft Power Meter makes use of the Maihak vibrating string sensor. This sensor is very accurate and reliable, long-term stable and calibrated like a calliper gauge.
The torsion of the shaft is transmitted to two shaft rings, which are clamped on to the shaft. The change in frequency of the vibrating strings measures the torque. External influences such as temperature, centrifugal forces and shaft bending will affect both sensors equally. Using two Maihak sensors thus compensates these external influences.
The vibrating string sensors are detached from the shaft, which gives several advantages. First, it is possible to check the fixation of both shaft rings and sensors. Second, the crew can easily calibrate the zero point of system. Third, it is possible to dismount the system for maintenance work on the shaft. In summary, vibrating string sensors are long term stable, accurate and reliable when measuring the torque of the shaft.