| 摘要 |
<p>PURPOSE: To improve the productivity of a searching operation by connecting an additional receiving loop signal balance, additional electric signal corrector, selective amplifier and signal display unit connected to a receiving loop perpendicular to the reverse side of an oscillating loop. CONSTITUTION: The metallic material searching apparatus comprises an inducing system 6 having an oscillating loop 1 and two sets of receiving loops 2, 3 and 4, 5, and an AC generator 7 connected to the system 6 and loop 1. The loops 2, 3 and 4, 5 are connected to the inputs 8, 9 and 10, 11 of receiving loop signal balances 12, 13. Electrochemical signal correctors 16, 17, selective amplifiers 18, 19 and data processors 20, 21 for canceling the effect of the primary electromagnetic field of the oscillating loop in differential amplifiers 14, 15, loops 2, 3 and 4, 5 are connected in series with the balances 12, 13. The output of the processors 20, 21 are connected to recorders 22, 23 and the inputs 24, 25 of OR circuits 26, and the output of the circuit 26 is connected to a signal display unit 27.</p> |
