Concentric-annulus electrical capacitance tomography sensors

The aim of this research is to investigate the unique shape (concentric-annulus) electrical capacitance tomography (ECT) sensors. This is motivated by the desire to improve the contrast and spatial resolution of the images reconstructed using ECT sensors with internal-external electrodes (IEEs). Both numerical simulation and experimental study were carried out with the goal of providing an improved understanding of the configuration of IEE sensors, the internal shield and the measurement strategies. Simulation results are in agreement with the experimental results. Using the linear back projection algorithm, the IEE sensor with 12 external electrodes and 4 internal electrodes with the external-opposite-internal measurement strategy can reconstruct high-quality images. In experimental studies, the internal shield may reduce the quality of capacitance measured from the internal electrodes.