ELECTROSTATIC CAPACITANCE TYPE LEVEL SENSOR AND ELECTROSTATIC CAPACITANCE TYPE LEVEL MEASUREMENT METHOD

摘要

PROBLEM TO BE SOLVED: To provide an electrostatic capacitance type level sensor and an electrostatic capacitance type level measurement method that enable a measurement error of permittivity to be reduced at low costs.SOLUTION: A computation unit 53 calculates tentative permittivityεon the basis of an electrostatic capacitance Cbetween a pair of permittivity detection electrodes 3 measured by an electrostatic capacitance measurement unit 51, and calculates a provisional liquid level Hon the basis of an electrostatic capacitance Cbetween a pair of measurement electrodes 2 and the tentative permittivityε. Further, the computation unit 53 calculates an error rate Efrom the provisional liquid level H, and calculatesεby correcting the permittivityεon the basis of the error rate E. The computation unit 53 correctsεby an error rate Eto calculateε, and repeats a permittivity correction process for calculating a liquid level H, thereby a measurement error of the permittivity can be reduced at low costs.