Torque sensors measure the rotary movement of a force or system of forces that cause rotation in an engine. They gauge the torque transferred along the drive-line axis at the place where the sensor is
positioned. These sensors measure torque by either sensing the shaft deflection caused by a twisting force or by sensing the effects that the deflection causes.
Torque sensors are also known as torque transducers and sometimes as torquemeters as well. Like load cells, torque sensors sometimes use strain gauges as their sensors, although this requires them to have a power outlet for the strain gauges as well as a program hooked up to interpret the electrical signals the strain gauges puts out. Since this can be complicated, there are other methods as well, listed in the paragraph below. Piezoelectric sensors and magnetoelastic sensors can also be utilized as the central piece for torque sensors.