The impedance of a coil near a conductor
"The results are given of experiments undertaken to determine the manner in which the apparent inductance and resistance of an alternating current carrying coil changes when it is brought near a plate of non-ferrous metal. The experiments were undertaken with a view toward applying the results to uses in the instrumentation field. A theoretical analysis of the situation is included which gives good results when the assumptions upon which it is based are fulfilled. This analysis is based upon a modification of the image coil method. The limitations of the analysis are indicated. Most of the results are given graphically and show the change of coil inductance and resistance as functions of distance from coil to metal, frequency, metal conductivity and a combination of two dissimilar metals, one upon the other."--Page 1.