Evaluation of Electrical Impedance Tomography System in an Innovative Sensing Strategy for Two-phase Solid-liquid Fluid Monitoring

Electrical impedance tomography (EIT) is a non-invasive imaging technique that measures properties of multiphase fluids such as particles distribution and volume concentration by injecting a current into a set of electrodes and reading voltages from the electrodes. A strategy of injection and signal measurement has an important role in the image reconstruction quality and measurement accuracy. In large phantoms with high-conductivity, conventional strategies such as adjacent are not able to measure the signal with suitable quality. Therefore, the purpose of this study is to construct and evaluate the EIT system under an innovative strategy for online determination of particles distribution and concentration of solid-liquid fluid in large phantoms. The sensors of this instrument consist of 16 circular electrodes. The liquid phase was water with known conductivity and solid phase was the bottle in different sizes and in three different situations. The results showed that the innovative strategy has the ability to recognize and differentiate the target in different dimensions and different positions. The signal-to-noise rate was 1.05 dB and the dynamic range of boundary potentials was 1600 mV. The sensitivity to the sides and near the electrodes was more than the sensitivity to the middle. In positions close to the electrodes, size error decreases in medium and large target. In the three sizes of the target, ringing has no negative effect on the reconstructed image quality. Therefore, it can be concluded that the innovative strategy has a desirable performance for determining the distribution of materials in the large phantom.