Patent ID: 6597186
Filing Date: 2003-07-22
Classification: G01F,G01N,G01R

Abstract:
The method for detecting a liquid level inside a ferromagnetic tank and resistivity within a tank to determine material characteristics associated with the tank comprising the steps(a) testing empirically to approximate the conductivity of the ferromagnetic tank wall; (b) testing empirically to approximate the permeability of the ferromagnetic tank wall; (c) creating a first set of electromagnetic waves adjacent to and electrically isolated from the outside tank wall to be measured of a relatively low frequency; (d) impinging the first set of electromagnetic waves on the tank wall for saturating the tank wall; (e) creating a second set of electromagnetic waves having specific constant amplitude of a higher frequency than the first set of electromagnetic waves, the second set of electromagnetic waves for engaging the tank wall also adjacent to and electrically isolated from the outside tank wall and generating a sensing signal having modified characteristics; and (f) receiving the sensing signal through the saturated tank wall such that the modified characteristics of the sensing signal are processed to determine the required information of liquid level and/or liquid type.