Patent ID: 6085589
Filing Date: 2000-07-11
Classification: G01F

Abstract:
A system for measuring level of material in a vessel that comprises:a transmission line probe adapted to be positioned for contact with material in the vessel such that an impedance discontinuity is presented along said probe at the air/material interface in the vessel,means for launching microwave radiation along said probe such that a portion of such radiation is reflected from said impedance discontinuity,means responsive to said reflected energy portion for determining level of said air/material interface with respect to said probe employing time-domain reflectometry,means responsive to said level-determining means for displaying level of said interface as a continuous function over a predetermined range, andmeans for calibrating said displaying means to said predetermined range with said probe disposed outside of the vessel comprising target means for selective positioning along said probe to reflect microwave radiation, and means coupled to said level-determining means for storing at least one signal indicative of one end limit of said range when said target means is at a first position along said probe, said level-determining means thereafter cooperating with said displaying means to indicate level of the air/material interface along said probe over said predetermined range with respect to said one end limit of said range.