| 摘要 |
<p>A device for detecting and testing magnetic-layer carriers without movement has an electromagnetic transducer arrangement (H) with two magnetic circuits (MC, MC') provided with air gap (AG, AG'). The magnetic-layer carrier is arranged at one of the air gaps (AG, AG'). Into the magnetic circuits (MC, MC'), an alternating current is fed in the same direction which produces a signal (A) proportional to the difference of the magnetic fluxes in the magnetic circuits (MC, MC'). Depending on its amplitude, this signal can be evaluated in an evaluation circuit (11 to 29) as a measure of different permeability areas of the magnetic-layer carrier tested. <IMAGE></p> |
