Torque sensor
From Wikipedia, the free encyclopedia
A torque sensor or torque transducer is a device for measuring the torque on a rotating system such as an engine crankshaft or a bicycle crank. Static torque is relatively easy to measure; dynamic torque is not, since it generally requires transfer of some effect (electric or magnetic) from the shaft being measured to a static system.
One way of achieving this is to condition the shaft with a series of permanent magnetic domains. The magnetic characteristics of these will vary according to the applied torque, and thus can be measured using non-contact sensors. Another way is to measure the torque on the crank itself (e.g. using strain gauges) and transmit the signal using a wireless system. This is only practical at low speeds.
