Vorrichtung und Verfahren zur aktiven Kompensation magnetischer und elektromagnetischer Störfelder

摘要

The invention relates to a device and a method for actively compensating magnetic and/or electromagnetic disturbance fields in a predetermined volume range, using at least one Helmholtz coil, said coil essentially covering this volume range, and a device for directing the Helmholtz coil depending on sensor signals. At least one first sensor (1) of said device is provided beyond the predetermined volume range for producing a signal (1a) which is also determined by the magnetic and/or electromagnetic field at the location of the sensor (1), and at least one second sensor (2) is provided within the predetermined volume range for producing a signal (2a) which is determined by the magnetic and/or electromagnetic field at the location of the sensor (2). The signals from the first and second sensors (1a, 2a) are used as an input signal (3a, 3b) for directing a regulator amplifier (3) belonging to the Helmholtz coil. After an empirically determined transmission function has been executed, the signal from the second sensor (2a) is applied to the regulator input (3b) of the digital regulator amplifier (3) and the output signal (3c) of the digital regulator amplifier (3) controls the current through the Helmholtz coil (4) in such a way that the magnetic and/or electromagnetic field in the predetermined volume range is at least partially compensated.