Evaluation of Voltage-driven Electrical Resistance Tomography Using LCR Meter-based Measurement System

Electrical resistance tomography (ERT) has been developed for monitoring the conductivity distributions in industrial applications with the advantages of low cost, no radiation and non-invasive. The traditional ERT system uses a scheme with current injection and voltage measurement to detect the changes in conductivity distribution. But the quality of measurement may become very poor under the background of low conductivity, e.g. the distilled water. In addition, it is difficult to achieve a satisfied SNR while maintaining a high dynamic measurement range. This paper presents a voltage-driven ERT system, which is based on LCR meter and custom-built switch array. Moreover, the system can accomplish the multi-channel resistance measurements by incorporating LCR meter with a custom-built programmable analog switch array. The system SNR has been calculated, and the tomogram for image verification under the background of different conductivity water has been conducted. Preliminary results show that the sysstem has the advantages of measurement under the background of low conductivity. Compared with other ERT systems, this system can apply to a large range of conductivity from $5\times 10^{4}$ S/m to $5\times 10^{2}$ S/m.