Multichannel detection unit for weak esp. biomagnetic field source - is provided with SQUID magnetometer in each detection channel switching part of signal processing electronic circuit and counter coupling branch

摘要

The counter coupling branch leads the circuit part to a counter coupling transformer. Inductive counter coupling signals are superimposed on the detected measurement signals to give a linearization of the superconducting quantum interference device (SQUID). In addition to the detection channels (Dn,Dn'), at least one compensation channel (K,K') is provided, for the prodn. of a quick compensation signal (31n, 31n',52n), which has a higher dynamic of the signal processing than the detection signal. At the switching part (26) following its SQUID (25), a rapid electronically obtained signal in the counter coupling branch (15,58) of the detection channels is fed via matching elements (34n,51n), so that the compensation signal is compensatorily superimposed, relative to the quicker interference signal, on the respective counter coupling signal (13,59) of the detection channels. Each SQUID magnetometer contains at least one DC SQUID (7,25,56). USE/ADVANTAGE - Detection unit (2) for weak esp. biomagnetic magnetic fields. Detection loops are provided as magnetometer or gradiometer. Cost of measures for interference field supression further reduced. Requirements for screening reduced. Simpler gradiometer can be used. Medical diagnostics.