A magnetic sensor is a sensor that detects the magnitude of magnetism and
geomagnetism generated by a magnet or current.
Magnetic sensors are used to detect magnetic fields and they are essential
tools for many engineering applications. Based on the applications, many
variations of magnetic sensors have developed which can be classified in few
groups: magnetic field sensors, magnetic position and distance sensors, magnetic
proximity switches, magnetic force and torque sensors, magnetic flowmeters and
current sensors etc.