Water volume measuring system using the capacitive sensor technique

Water measurement systems have been used by many electo-electronic devices. Most common measurement systems have been used boil and pressure sensors approaches. This article aims to study capacitive sensors using the charge transfer technique for measuring water volume. This technique is based on electrical charge variation storage in a capacitor which depends on the dielectric constant of material close to the sensor. This technique is compared to other methods for calculating the total volume of a tank, such as the one which uses hydrostatic sensor and visual. The charge transfer method was developed by Atmel®. It was also investigated the influence of container material and its geometry. It was used the Atsamd21-xpro evaluation board for taking the measurements. Four different tank volumes were analyzed ranging from 0.25 to 14 liters. Glass and plastic tanks were also used. The results showed that the capacitance measurement depends on both material and geometry of the tank. It can be concluded that this method can be easily implemented on commercial devices for a given transfer function.