Experimental Study of the Guard Electrodes in an ERT System

The electrode array in an ERT system has a great influence on the system's performance. In this paper, experiments have been carried out to study the effect of guard electrodes for sensing field of an ERT system. Under homogenous medium condition, the comparison between measured data and simulated data obtained by using a two-dimensional(2-D) formula showed that, the electrode array with guard electrodes produces a sensing field with a near parallel distribution. Under heterogeneous condition, the effect of guard electrodes to compress the distribution region of sensing field is tested. Some qualitative analysis of experimental results are given.