MAGNETIC SENSORS FOR INDUSTRIAL AND FIELD APPLICATIONS

Vector-type magnetic-field sensors suitable for use in a heavy industrial environment and for field measurements include Hall sensors, magnetoresistive sensors and fluxgates. The basic properties of these sensors are discussed. Hysteresis and offset of the permalloy anisotropic magnetoresistance sensors can be lowered by periodically flipping the sensor characteristics. While low-noise fluxgate sensors may work in the sub-nanotesla range and miniature fluxgates may still have nanotesta (nT) resolution, the typical measuring range of permalloy anisotropic magnetoresistors starts at tens of nT and the resolution of ordinary Hall sensors is of the order of 10 muT.