Effectiveness of Electrical Capacitance Volume Tomography Method in Soil Water Content Measurement

Abstract

Many researchers, in the recent years have developed various techniques for determining water content of the soils. Electrical Capacitance Volume Tomography (ECVT) is one of the techniques developed by using various types of sensors to improve the quality and effectiveness in the determination of water content in the soil. The technology is based on the capacitance measurement generated from a whole volumetric image of the region which is surrounded by three-dimensional geometry capacitance sensor. This study was carried out to determine the effectiveness of ECVT in measuring soil water contents in fine sand and silty sand to compared with the gravimetric method. Results analysis show that the correlations of the water content measurement R2 using ECVT and gravimetric methods for fine sand and silty sand are very good, about 0.978 and 0.988, respectively. These suggest that ECVT method has a good potential in determining the soil water content in this respective soil type.

3D Image Reconstruction Capability of Peripheral On-chip ECT Sensor

“…To investigate the 3D imaging capability of the peripheral on-chip ECT sensor, the optimised sensor design from [20] has been adopted with parameters as illustrated in Figure 1. The sensor was modelled in 3D instead of 2D to obtain the distribution of electric field in the z-axis direction which is vital for height sensing.…”

“…The electrodes were rectangle in shape with a length of 2.67 mm and width of 2.08 mm. According to [20], the electrodes were peripherally arranged to obtain capacitance measurement from different angles through the fan beam projection which enhance the resolution of reconstructed image. Meanwhile, the length of the electrode was chosen as 2.67 mm so that the electric field reaches the top of sensing chamber for thorough sensitivity coverage.…”

“…The feasibility of miniature ECT sensor was investigated by [19] for lab-on-chip applications and showed that the capacitance measurement could be measured and agreed with the simulated capacitance trend. Meanwhile, [20] investigated the 2D imaging of multiphase flow using miniature ECT sensor and the reconstructed 2D images showed high similarity to the camera-captured image. Besides, [21] performed a simulation study using miniature ECT sensor on the sensing of yeast cells and the results showed that miniature ECT sensor could detect the presence of yeast cell model.…”