Comparison of different measurement protocols in electrical capacitance tomography using simulations

A major problem in electrical process tomography is that there exist relatively few measurement variables, as compared with the desired resolution of the reconstructed image. This, in addition to the ill-behaved inverse problem involved, makes the image reconstruction problem difficult and severely under-determined. Using more complex measurement protocols, in addition to an increased number of electrodes, introduces smaller rotational steps of the electric field. More information about the material distribution is obtained, and an increase in the image fidelity may be expected. In this paper, the image fidelity using protocol 3 is compared with the results using the conventional protocol 1. In addition, some performance metrics to assess the fidelity of the protocols are used in the final stage of the analysis. The results are based on simulations using COMSOL Multiphysics and MATLAB.