What is the working principle of a torque sensor?

2024-05-17

A torque sensor is a device used to measure torque or rotational force. Its operating principle is based on the strain characteristics and resistance changes of materials. Under the action of torque, the elastic body inside the sensor deforms, causing a change in resistance. The sensor usually contains an elastic body and a resistance strain gauge; the elastic body deforms under the influence of torque, causing a change in the resistance value on the resistance strain gauge.

When torque is applied to the sensor, the elastic body inside the sensor deforms under the action of force. This deformation causes a change in the resistance value on the resistance strain gauge. Typically, the resistance strain gauge is a resistance coil deposited on an elastic body. When the elastic body deforms, the length and cross-sectional area of the resistance coil change, thereby changing the resistance value. Based on the change in the internal resistance value of the sensor, the magnitude of the external torque applied to the sensor can be derived.

In addition to the resistance strain principle, torque sensors also have other operating principles, such as the piezoelectric effect and electromagnetic induction. In the piezoelectric effect, the piezoelectric material inside the sensor produces a change in charge, which can be used to measure the torque value. In the electromagnetic induction principle, changes in the magnetic field are generated inside the sensor, inducing an induced current to achieve torque measurement.

In general, the working principle of a torque sensor is mainly based on the strain characteristics and resistance changes of materials. By measuring the change in the internal resistance value of the sensor or the charge change of the piezoelectric material, the accurate measurement of the external torque applied to the sensor can be achieved. This principle makes torque sensors widely used in industrial production, the automotive industry, aerospace, and other fields.