Patent ID: 6359449
Filing Date: 2002-03-19
Classification: G01R

Abstract:
A method of quantitative measurement of the resistance of a remote substance using a single coil comprising the steps of:(a) exciting the coil with an electrical signal to produce an electromagnetic field enveloping the remote substance; (b) allowing the frequency of the electric signal to be at the resonant frequency of the coil as affected by the remote substance; (c) adjusting a control signal controlling the amplitude of the electrical signal so that the electric signal at the coil substantially equals a predetermined standard level; and (d) deriving a resistance value of the remote substance based on the adjusted control signal independent of any deformation of the coil, wherein the resistance value of the remote substance is only substantially indicative of a real portion of an impedance of the remote substance and is not substantially indicative of any reactance or inductance of the remote substance or the coil.