Interference magnetic field compensation method which includes supplying a current to a coil to compensate the field

摘要

Method for compensating the interference magnetic field of an object by means of an interference field controlled magnetic self-protection system having a coil system connected to receive a magnetic field producing current and oriented to produce a magnetic field tending to compensate the interference magnetic field, which method includes: monitoring a magnetic field difference at a selected location relative to the object; providing a representation of the value of the magnetic moment of the object; and controlling the current supplied to the coil in dependence on the monitored magnetic field difference and the value of the magnetic moment.