ABSTRACT
In this paper, a liquid-level measurement method is discussed by using a capacitive rotary sensor. The proposed arrangement consists of two parts: sensing module and signal processing circuit module. The sensing module composed of three segments: float arm, dielectric plate, and two copper plates. In this module, the float arm is mechanically connected to a dielectric plate, by which it can rotate in any direction due to variation in the liquid level in a tank. Then, two copper plates are arranged in parallel at either side of this plate, and due to the movement of the float arm, variation of capacitances was achieved by the tapping of the two plates. These capacitances are converted into voltage variation by using a signal processing circuit module, and through a universal serial bus, it is transmitted to a computer for analysis using the LabVIEW software. In this paper, a prototype of this method is designed to measure the liquid level in the range of 0 cm to 30 cm.
