Single-shot charge-discharge circuit for dynamic electrical capacitance tomography

Electrical capacitance tomography (ECT) can be applied for imaging of dynamic processes in several chemical process installations. A very low value of inter-electrodes capacitance measured in the tomographic sensor is the main cause of low image resolution of this imaging technique. This limits applications of ECT. In this paper the first results of measurements performed using the specialized electronic circuit for very low capacitance measurement is presented. The circuit is a modification of the charge-discharge circuit but enables much higher speed of measurement due to single charge-discharge cycle. The frame rate of 350 frames/s was obtained for 16 electrodes. The circuit has good sensitivity, low noise and linearity. The results of first measurements and image reconstructions are shown.