A magnetic sensor for discriminating between high and low coercivity magnets is disclosed. The sensor comprises a first magnetic field operable to orient high and low coercivity magnets in a first magnetic orientation. The sensor also comprises a second magnetic field, lower in strength than the first magnetic field, and operable to orient only the low coercivity magnets in a second magnetic orientation opposite to the first magnetic orientation. The sensor further comprises a sensor for ascertaining the magnetic orientation of each of the magnets and thereby identifying if a magnet is a high coercivity magnet or a low coercivity magnet.