Study on Liquid Level Sensor Based on Principle of Variable Media Capacitance Sensing

Aiming at the problems of the poor water quality and bad measurement environment,a new liquid level sensor based on the variable media capacitance principle was designed.The liquid level was converted to capacitance value by Teflon coaxial cable,and then the capacitance value was transformed to standard voltage through the special circuit.Finally the average filter and interpolation method was synthetically used to fit the system curve and to eliminate interference error,thus the nonlinear correction was implemented.The result of test shows that the designed sensor has a higher measurement accuracy,and it is suitable for the water level detection under different complicate environments.