Large vol. reduction appts. for magnetic fields, pref. of low frequency - measures magnitude, direction and time variation of field and generates compensating field accordingly

摘要

The appts. for reducing a pref. low frequency magnetic field in a defined vol. measures the magnitude, direction and time variations of the field and generates a compensating field of opposite direction, the same magnitude as far as possible and the same time characteristic. The measurement probes are induction coils (MS1-MS3) and/or magentic field sensitive semiconductor elemnts such as Hall probes. Several probes are distributed around the field compensated chamber and their measurement values are evaluated accordingly to achieve compensation. USE/ADVANTAGE - E.g. for use in vol. equivalent to substantial parts of building (1). Enables reduction of pref. low frequency magnetic fields varying in all their parameters.