METHOD AND DEVICE FOR MEASURING WATER LEVEL UTILIZING CAPACITOR

PROBLEM TO BE SOLVED: To compensate for measuring errors automatically and to perform precise measurement by applying a DC voltage on a reference capacitor and each measuring capacitor, and confirming the difference between the magnitude of the electric signal of each capacitor and the electric signal generated in the reference capacitor. SOLUTION: A fixed flange 4 and a cap flange 3 are made to have the watertight constitution. An outer pipe 5 and an inner pipe 6 are concentric. The lower edge of the pipe 5 is closed. A reference capacitor 8 provided at the lowermost part is always immersed in liquid. Liquid paths 10 are provided at a plurality of parts in the longitudinal direction in the pipe 5. The liquid can be inputted and outputted at the part from a measuring capacitor 7 provided at the uppermost side to the capacitor 8. The electrostatic-capacity signals of the capacitor, which is completely immersed in the liquid, and the capacitor 8 are equal. The difference occurs between the electrostatic-capacity signals of the capacitor 7, which is completely exposed on the liquid surface, and the capacitor 8. The depth of the liquid is obtained by confirming these electrostatic- capacity signals.