A torque sensor, torque transducer or torque meter is a device for computing and recording the torque on a rotating system, such as an engine, crankshaft, gearbox, transmission, rotor, a bicycle crank or torque sensor. Static torque is relatively simple to measure. Dynamic torque, on the other hand, can be difficult to measure, as it generally requires transfer of some impact (electric, hydraulic or magnetic) through the shaft being measured to a static system.

One method to accomplish this is to condition the shaft or a member attached to the shaft with several permanent magnetic domains. The magnetic characteristics of those domains will vary in accordance with the applied torque, and therefore can be measured using non-contact sensors. Such magnetoelastic torque sensors are usually used for in-vehicle applications on racecars, automobiles, aircraft, and hovercraft.

Commonly, torque sensors or torque transducers use strain gauges applied to a rotating shaft or axle. With this method, a method to power the strain gauge bridge is important, in addition to a methods to have the signal from the rotating shaft. This is often accomplished using slip rings, wireless telemetry, or rotary transformers. Newer kinds of torque transducers add conditioning electronics and an A/D converter to the rotating shaft. Stator electronics then read the digital signals and convert those signals to a high-level analog output signal, like /-10VDC.

A much more recent development is using SAW devices connected to the shaft and remotely interrogated. The force on these tiny devices because the shaft flexes could be read remotely and output without making use of attached electronics on the shaft. The probable first use within volume will be in the automotive field as, of May 2009, Schott announced it has a SAW sensor package viable for in vehicle uses.

An additional way to multi axis load cell is by way of twist angle measurement or phase shift measurement, whereby the angle of twist caused by applied torque is measured by making use of two angular position sensors and measuring the phase angle between the two. This technique can be used inside the Allison T56 turboprop engine.

Finally, (as described inside the abstract for people Patent 5257535), when the mechanical system involves the right angle gearbox, then your axial reaction force felt by the inputting shaft/pinion may be related to the torque gone through by the output shaft(s). The axial input stress must first be calibrated from the output torque. The input stress can be nanzqz measured via strain gauge measurement of the input pinion bearing housing. The output torque is easily measured using a static torque meter.

The torque sensor can function such as a mechanical fuse and it is an important component to get accurate measurements. However, improper installation of the torque sensor can harm the device permanently, costing time and money. Hence, the torque sensor must be properly installed to make certain better performance and longevity.

The performance and longevity of the compression load cell as well as its reading accuracy will likely be afflicted with the appearance of the driveline. The shaft becomes unstable on the critical speed in the driveline and results in torsional vibration, which can damage the torque sensor. It is actually required to direct the strain to an exact point for accurate torque measurement. This point is usually the weakest reason for the sensor structure. Hence, the torque sensor is purposely made to be one of the weaker elements of the driveline.