I. Introduction
Electrical resistance tomography (ERT) is an important process tomography (PT) technique in the research field of gas-liquid two-phase flow [1]–[14]. However, the conventional ERT is on the basis of contact detection, which may result in unfavorable effects, such as electrode polarization, electrochemical erosion and electrode contamination [1]–[14]. By introducing capacitively coupled contactless conductivity detection (C4D) technique into electrical tomography (ET), capacitively coupled electrical resistance tomography (CCERT) is proposed as an improvement of ERT [1]–[14]. With the contactless measurement characteristic of C4D, the electrodes of CCERT are not in contact with the measured fluid and the mentioned drawbacks of the conventional ERT could be avoided. Therefore, CCERT has good potential in the research field of gas-liquid two-phase flow, which has attracted much attention since proposed.