Patent ID: 6857313

Claim:
A gauge suitable for measuring a level of fluid in a container, the gauge comprising: a first capacitive element having a measured capacitance that varies for a first range of fluid levels; a second capacitive element having a measured capacitance that varies for a second range of fluid levels; a nonvolatile memory for storing a reference capacitance of said first capacitive element representative of a situation where none of said first capacitive element is submerged in the fluid; and a control unit for determining whether conditions are satisfactory for performing a calibration routine, wherein the control unit determines whether conditions are satisfactory based on a comparison of the measured capacitance of said first capacitive element to the reference capacitance of said first capacitive element, wherein, when said conditions are determined to be satisfactory, the control unit determines a dielectric constant of the fluid based on a calculation involving the measured capacitance of said second capacitive element.