SIMULTANEOUS MEASUREMENTS OF THE RESISTANCE AND CAPACITANCE USING A CYLINDRICAL SENSOR SYSTEM

Abstract

In this article, the design and operation of a cylindrical capacitive sensor based on the dielectric reactance capacitance and conductance changes of the gap medium is reported. The proposed system was used to determine characteristics of different water liquids as a result of the capacitance and resistance variations. The air gap capacitance (dry signal) is measured and then by filling the gap with a liquid, the capacitance (wet signal) is monitored for different liquids. A reported sensor is used for the distilled, tap, boiled, and salt water measurements and the capacitance and resistance results are compared. A big difference of about 38.5 μF in the measured capacitance values for the salt and distilled water shows a high sensitivity, which can be used to recognize different water liquids. The experimental results are promising for water liquids and verify the successful operation of such a device as a liquid sensor, a useful method for checking the electrical quality of the water that is required for different applications. It is also possible to monitor the resistance change of the filling medium as a function of time.