New cancellation technique for electromagnetic induction sensors
Waymond R. Scott, Michael Malluck · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2005
A new technique is presented for canceling the coupling between the coils of an electromagnetic induction sensor while using simple dipole detection coils. A secondary bucking transformer is used to cancel the coupling between the coils. The technique allows the cancellation that can be obtained using a quadrupole receive coil while maintaining the depth sensitivity and simple detection zone of a dipole coil. Simple circuit models for the sensor with some of the important parasitic effects are developed. An experimental model is developed and used to demonstrate the technique. Experimental results are presented that demonstrate more than 75 dB of cancellation up to 100 kHz and the response of the sensor to a few targets.