| 摘要 |
Capacitive gauge for fuel tank comprising a measurement capacitor, a reference capacitor and at least one standard capacitive device, fed by and connected to an electronic interpretation circuit comprising switches for charging and discharging the capacitors and the capacitive device at a certain frequency; an integrator to which the charges of the measurement or reference capacitor can be transmitted and accumulated before being discharged into the standard capacitive device; a comparator for comparing an output value of the integrator with a threshold value; a counter; and a processor or computation unit for calculating the level of liquid in a fuel tank according to the equation: h = [n ref,empty/(n ref-n ref,empty)]. [(nmeas-n meas,empty)/n meas,empty], where n are the values read by the counter respectively for the capacitance of the reference capacitor when empty (n ref,empty), for the capacitance of the reference capacitor immersed in the fuel (n ref), for the capacitance of the measurement capacitor when empty (n meas,empty) and for the capacitance of the measurement capacitor in the liquid to be measured (n meas); the standard capacitive device comprising at least two standard capacitors with electrical connections to the measurement capacitor.
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