SQUID measuring system for determining weak time dependent magnetic fields - has at least one measuring channel with SQUID and one superconducting directional loop

摘要

The superconducting directional loop receives the field signals of the field source, and for the prodn. of corresp. measurement signals in the channel. It also provides for the suppression of interference signals, the frequency of which is at least twice as high as the frequency of the field signals. For at least a partial interference field suppression, one suppression circuit (18) is provided, with a super conducting screening loop (13a-13f), which has at least one interuption (16), bridged by means of an impedance element (17). The inductance (L) and the impedance value (L) of the suppression circuit, with regard to a least one partial suppression of the interference signals (11), are so designed, that a weakening of the field signals (4) or the corresp. measurement signals (5) is excluded. ADVANTAGE - Squid measuring system with detection loop designed as magnetometer or gradiometer allows redn. in cost of measures for interference suppression. Esp. screening requirements can be reduced.