AC magnetic flux density measurements with 200 pT resolution using magnetoresistive sensors

Magnetoresistive devices, resembling Wheatstone bridges in most configurations, are an emerging technology used to sense both DC and AC magnetic flux density. Magnetoresistive devices are especially desirable for certain demanding applications because of their small physical size, acceptable power consumption, reasonable sensitivity, and their ability to provide a one-dimensional projection of a magnetic field or magnetic flux density. This paper discusses the performance of an orthogonal magnetoresistive triad used to perform a three-dimensional Cartesian field decomposition for an industrial AC magnetic flux density problem. This experience suggests magnetoresistive sensors are capable of 200 pT resolutions in relatively demanding environments