Magnetostrictive Torque Sensors and Materials

Shaft torque sensors based on the magnetostriction effect and magnetostrictive materials used in such sensors are reviewed. Torque sensors employing amorphous ribbons in a chevron pattern and with solenoidal pickup coils have been developed for highly sensitive torque measurements in an intermediate dynamic range. Magnetic head torque sensors are simple in structure and robust, but require further study before they can be used in applications where instantaneous torque detection is important. Approaches to improving zero-level fluctuations and reducing hysteresis in torque sensors are summarized.