| 摘要 |
PROBLEM TO BE SOLVED: To obtain a method and an apparatus in which a weak signal in a noisy environment can be multichannel-measured by a method wherein a plurality of signal channel outputs are cross-coupled into a stage before the output of signal channels and a compensating channel is arranged between the plurality of signal channel outputs and the stage before the output of the signal channels. SOLUTION: A compensating channel is provided with a summing operational amplifier. The output of every real channel of the scanning operational amplifier is connected to the input of an amplifier 4, and the output is connected again to the feedback of every channel. The negative feedback of every channel itself and a cross-coupling feedback from a compensator channel are added, e.g. by other operational amplifiers 5, 6, and they are coupled to sensor elements 1, 2 via every feedback coil. Regarding a cross-coupling constant, a 'forward coupling operation' is multiplied by the reciprocal number of resistors R12, R13, and a 'reverse coupling operation' is multiplied by the reciprocal number of resistor R21, R31. The total multiplication of a matrix element is decided by a resistor Rf. |
