Conversion Theory of Magnetic Anisotropy Sensor

A magnetic anisotropy sensor (MAS) enables the noncontact measurement of mechanical stress in ferromagnetic materials. This paper deals with the conversion theory of the MAS output voltage, utilizing a directional permeability distribution which assumes an elliptical form in the specimen. The relative permeability is proportional to the stress, and the theoretical expression for the output voltage is derived from the concept of a directional permeability distribution. The calculated values for the output voltage are comparatively close to measured values due to changes in stress.