초록 ▼

A gauging apparatus for fluid containers such as fuel tanks includes a capacitance disposed in the container that changes value based on the volume of fluid in the container; a first antenna disposed below an outer surface of the container and coupled to the capacitance; a second antenna magneticall

A gauging apparatus for fluid containers such as fuel tanks includes a capacitance disposed in the container that changes value based on the volume of fluid in the container; a first antenna disposed below an outer surface of the container and coupled to the capacitance; a second antenna magnetically coupled with the first antenna across a coreless gap; and a gauging circuit coupled to the second antenna and comprising an oscillator for applying an excitation signal at a number of different frequencies to the second antenna, and a signal processing circuit that detects current in the second antenna caused by the excitation signal and by current in the first antenna related to the capacitance value.

대표청구항 ▼

Gauging apparatus for fluid containers comprising: a capacitance disposed in the container that changes value based on the volume of fluid in the container; a first antenna disposed below an outer surface of the container and coupled to the capacitance to form a resonant circuit having a resonant fr

Gauging apparatus for fluid containers comprising: a capacitance disposed in the container that changes value based on the volume of fluid in the container; a first antenna disposed below an outer surface of the container and coupled to the capacitance to form a resonant circuit having a resonant frequency that is a function of the capacitance value; a second antenna magnetically coupled with the first antenna across a coreless gap; and a gauging circuit coupled to the second antenna and comprising an oscillator for applying an excitation signal at a number of different frequencies to the second antenna with the resonant circuit operating as a load for the gauging circuit with the load changing in relation to the capacitance value, and a signal processing circuit that detects said resonant frequency based on detecting current amplitude in the second antenna during application of said excitation signal and as a function of said load.