Design, Development and Testing of a Semi Cylindrical Capacitive Array Type Liquid Interface Level Sensor

Abstract

In this study, a semi cylindrical capacitive array type liquid interface level measuring sensor is described. The sensor consists of a continuous large semi cylindrical thin metallic plate acting as a common plate of the capacitor and an array of small semi cylindrical thin metallic plates, separated by very small gap distance. All plates are mounted along the outer wall of a cylindrical non conducting vertical storage tank. The detection of liquid interface is based on the measurement of capacitance of the array of plates which varies with the dielectric constant of the liquid within the tank. The measured capacitance has been obtained in nano farad range. Since the sensor is non contact type, it can be used for both conducting and non conducting type of liquid contained within a non conducting tank. Experimental results confirm the satisfactory performance of the sensor for liquid interface level measurement.