Torquemeters from S.Himmelstein & Co.

There are two major types of Torque Transducers:

Reaction Torquemeters ...these devices do not have rotating components. They measure torque in static or quasi-static applications, such as the torque experienced by a soda bottle, when its cap is twisted.  

Rotating Torquemeters ...these devices have a stationary housing and a rotating shaft. They measure torque in (mostly) dynamic applications, such as the torque in a spinning shaft between a motor and a pump.