Torque sensors are used for measuring the torque on a rotating system such as an engine crankshaft or a bicycle crank. It is also called as torque transducer. It measures the turning effort required to rotate a mass through an angle. The typical application of torque sensor includes motor quality control or conversion of rotary to reaction torque. Static torque is relatively easy to measure, as it generally requires transfer of some effect (electric or magnetic) from the shaft being measured to a static system.
Torque Wrenches are designed to tighten nuts, bolts and fittings to a measured degree of tightness. The three most commonly used torque wrenches are the flexible beam, rigid and ratchet types.