Contactless signal and energy transmission
Digital display of current r.p.m.
, troque, power and energy values in manouvring and navigation mode and
selective display of average values for 1, 4, or 24 hours
Thrust measurement may be included
The torsionmeter is based on the shaft deformation measurement with a strain gauge transducer glued on the shaft. The resistance change of gauges connected in a Wheatstone bridge is proportional to the shaft torque and converted into the frequency.
The supply of electric power to the shaft measuring electronics and signal transmission from the shaft is contactless.
The interpretation method of the measured signals is also one of the outstanding features of the Brolich torsionmeter. The shaft is deformed under the influence of combustion process and the limited number of cylinders of diesel engines in addition to the hydrodynamic excitation due to the irregular inflow to the propeller. The variable loading of the shaft is a complex non harmonic function which contains a high part of the transmitted power on diesel propelled vessels. Further, the rolling of the ship leads to the slow shift of the mean torque value.
The exact measuement under these conditions is performed by time integration of signals. The application of the frequency modulation prnciple allows the consideration of signal carrier as reference or zero point wich is digitally separated from the modulation value proportional to the torque. At the end of the measuring interval, the area integral is built and digitally displayed as the torque value.
The auto zero algorithm is based on the analysis of the shaft rotating status and previously set zero values.
The shaft speed is measured with a contactless proximity switch counting slots or the time between the passage of one slot built in the mechanical shaft part.
The built in calibration allows calculated torque simulation, system function check and an accuracy check.