Industrial Torque Measurement Using Magneto-Strictive Torquemeters

A magneto-strictive torque transducer comprises a length, of the order of 6 inches, of solid or hollow shaft of ferro-magnetic material equipped with magnetization and signal pickup windings. A variety of stationary and rotating coil systems can be employed, but all are characterized by a mutually perpendicular arrangement of the magnetization and pickup coils so that no voltage is induced in the latter by the alternating magnetizing current at no load. Torque diverts some of the flux to the pickup coils, the EMF thereby produced being a measure of the torque.