Abstract: In electrical resistance tomography system (b;R`I})，the sensitivity-field is influenced by the distribution of multiphase flows. As a prior knowledge of image reconstruction, sensitivity-field distribution data must be computed on theory. I}o improve the quality of reconstruction image, it is necessary to analyze the sensitivity-field distribution. In this paper, based on the basic principle of electrical resistance tomography, finite clement method was adopted to build a mathematical model of sensitivity-field. Based on the analysis of sensitivity-field, the factors and rules that affect sensitivity-field distribution were studied, and the computation of distribution and visual simulation were finished. According to the computation of sensitivity-field distribution, an image reconstruction algorithm accelerated by polynomial for electrical resistance tomography and corresponding mathematical model were brought forward, and the convergence feature of the algorithm was proved using spectrum analysis. The result of simulation and experiment shows that the finite element module of sensitivity-field is effective. The image reconstruction algorithm has the advantages such as high quality and fast convergence speed,which brings forward a new method to the research of ERT image reconstruction.

Key words: Electrical resistance tomography, Finite element method, Sensitivity field, Image reconstruction algorithm