Noncontact torque sensor using the difference of maximum induction of amorphous cores

A novel noncontact torque sensor which uses the difference of the maximum magnetic induction of two cores was constructed. The torque sensor utilizes the change in the maximum magnetic induction by AC magnetization due to the stress-induced magnetic anisotropy of negative magnetostrictive amorphous ribbons which are attached on a rotatable shaft in a chevron pattern. This sensor shows that the linearity was better than 1%, and the transient torque can be measured at the sampling rate of 10 kHz, which is the same as the magnetizing frequency of the core.<>