High-precision electrical resistance tomography with external and internal electrode arrays

Electrical resistance tomography is considered as a promising tomography technology in many industry processes. Classical ERT usually reconstructs internal resistivity distribution from the measurements on the surface. Its spatial resolution, especially near the center of the reconstructed domain, is limited by the relatively low numbers of independent measurements positions and the soft-field character of electrical field. To improve this condition, a novel ERT sensor structure with eight internal electrodes and sixteen external electrodes is presented in this paper. The internal electrodes are attached on a bluff body across the object pipe, and the external electrodes are fixed on the inner wall. Under some excitation strategy, these internal and external electrodes can be utilized as current injections and voltage measurements. After some numerical simulations, some advantages of this novel structure have been found. Firstly, the sensitivity field of this novel structure is more homogeneous comparing with the classical structure. Secondly, more information about the observed field can be obtained using this novel structure. Finally, reconstruction results from this novel structure have lower average errors and are more correlated with the actual distributions. Therefore the high-precision electrical resistance tomography can be got using this novel ERT sensor structure.