Measuring equipment with field-sensitive gradiometer loop arrangement - contains integrated DC SQUID with parallel adjacent sub-loops and noise-suppression circuit for HF noise

摘要

Two or more groups of parallel sub-loops (3a-3d,4a-4d) are arranged adjacent to each other. A noise suppression circuit (18) contains a superconducting screening loop (15) arranged in parallel with at least parts of the sub-loops and with at least one opening (16a,16b) bridged by an impedance element (17a,17b). The inductance and impedance of the suppression circuit are selected for at least partial noise suppression without attenuating the field signal (7) to be detected. USE/ADVANTAGE - Detecting weak, time varying magnetic fields. Effective suppression of h.f. noise is achieved with effective flux coupling of l.f. measurement signals.