Optel-Texys, a product line of Texys America, has developed a contactless method for measuring torque on shafts. To accomplish this, two Optel-Texys 152 G7 sensors and optical probes are placed at each end of the shaft. These sensors measure incremental pulses on contrasting elements, such as alternating black and white stripes or teeth on a gear wheel. These are non-laser optical sensors operating using near-infrared light. The fiber-optic probes allow the sensors to be mounted remotely while measuring in harsh environments such as oil or water sprays.
The data from the sensors is output to the data system via TTL. This output can be used to extrapolate the trigger wheel’s speed and position. From the angular position of each trigger wheel, using an algorithm and known values such as the shaft geometry and physical properties, the torque value can be calculated. Bench tests have shown a minimum angular position measurement of 0.001° and a calculated torque value within 0.02% of the CFD results.