State of the Art Magnetoresistance Based Magnetic Field Measurement Technologies

Magnetic field based magnetoresistance (MR) sensors are used in a wide range of applications to detect current, rotation, motion, position, and other parameters. Different sensor types are utilized for sensing magnetic fields. In order of technical progress, the important MR sensors are anisotropic magnetoresistance (AMR), giant magnetoresistance (GMR), and tunnel magnetoresistance (TMR). Sensors based on the Hall effect are used in clamp ammeters. These were some of the first magnetic sensors used but they suffer from the disadvantages of low sensitivity and nonlinearity. Colossal magnetoresistance (CMR) technology has been discovered that is related to thin‐film MR material. It was found that CMR sensors have higher MR characteristics than GMR sensors. The relatively new TMR sensor technology has better temperature stability, high sensitivity, a wide linear range, and does not require a set–reset coil, unlike AMR and GMR technologies. The chapter summarizes the characteristic features of commonly used MR sensor technologies.