CAPACITANCE-TYPE LIQUID LEVEL MEASURING APPARATUS

PROBLEM TO BE SOLVED: To obtain a capacitance-type liquid level measuring apparatus by which the level of a liquid inside a tank can be measured in real time and continuously, by applying a high frequency across both electrodes of a level sensor, which is composed of a detecting electrode and a shielding electrode, and measuring the interelectrode voltage. SOLUTION: A level sensor 20 is composed of a rod-shaped detecting electrode 22 and of a cylindrical shielding electrode 24 which is arranged coaxially. When the level sensor 20 is inserted into a liquid inside a tank, the liquid flows into the level sensor 20, and both levels become equal. Then, when a high frequency is applied across both electrodes by an oscillator 12, the capacitance of the level sensor 20 is changed due to a change in the levels. An interelectrode voltage which is changed due to the change is measured by a voltage measuring device 14. Thereby, the change in the levels of the liquid inside the tank can be detected continuously. At this time, by using a linearity correction resistance 16 which is corrected to an optimum value by a correction resistance setter 30, the nonlinearity of an interelectrode voltage-capacitance characteristic can be corrected to be linear.