Characterization of a multi-plane electrical capacitance tomography sensor with different numbers of electrodes

Choosing the number of electrodes is crucial for a multi-plane electrical capacitance tomography (ECT) sensor to obtain satisfactory capacitance data and good image quality. In this paper, issues with the number of electrodes in three-plane ECT sensors are discussed. The number of electrodes on each plane for the three sensors is 4, 8, and 12, respectively. Three quality measures of resolution matrix, i.e. the amplitude response, relative position error, and spatial resolution, are defined and used for evaluating the preliminary performance of ECT sensors. Based on numerical simulation, the noise-free and noisy capacitance data obtained from the three sensors are used for image reconstruction by linear back projection (LBP) and Landweber iteration algorithms. The image quality is evaluated quantitatively in terms of image error and correlation coefficient. Based on static experiment, the effect of the number of electrodes on the quality of the capacitance data and reconstructed images is also analyzed. According to the numerical simulation and experiment results, the selection of the number of electrodes under different conditions is suggested.