Performance evaluation and structure optimization of an inner-outer electrical resistance tomography sensor

Electrical resistance tomography is a useful visualization technique to imaging the conductivity distribution inside a closed pipeline from the boundary measurements. Due to its advantages of high speed, low cost and high safety, the technique has been successfully applied in the measurement of many industrial processes. However, since the mathematical model is highly non-linear and ill-posed, the spatial resolution of ERT is low, especially in the center of the objective domain. To overcome the problem, an inner-outer ERT sensor structure was proposed. The structure is consisted by the internal and external electrodes, and can provided more independent measurements for high resolution image reconstruction. To test the performance of the inner-outer sensor structure, six inner-outer ERT sensors are designed, and the influences of the size, number and distribution of the internal electrodes are discussed. After several numerical tests, the inner-outer ERT sensor is proved having the ability of enhancing the spatial resolution of ERT, especially in the area near the internal electrodes.