| 摘要 |
A first sensor of the device for compensating magnetic and/or electromagnetic disturbance fields in a predetermined volume range is provided beyond the predetermined volume range for producing a signal that is determined by the magnetic and/or electromagnetic field at the location of the sensor. A second sensor is provided within the predetermined volume range for producing a signal which is determined by the magnetic and/or electromagnetic field at the location of the sensor. The signals from the first and second sensors are used as an input signal for directing a regulator amplifier belonging to a Helmholtz coil. After executing an empirically determined transmission function, the signal from the second sensor is applied to the regulator input of the digital regulator amplifier and the output signal of the digital regulator amplifier controls the current through the Helmholtz coil such that the magnetic and/or electromagnetic field in the predetermined volume range is at least partially compensated.
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