Design of ERT/ECT dual-modality process tomography system

With the development of multiphase flow, real-time tomography system sensitive to various electrical parameters is required, i.e. multi-modal real-time tomography system. From the perspective of the electromagnetic field theory, electrical resistance tomography (ERT) and electrical capacitance tomography (ECT) are classified to a same mathematical model. Composite sensor array and hardware circuit featured with topological structure for the ERT/ECT dual-modality system are designed. The system can run in single modality or dual modality, fusion of ERT and ECT is realized primarily. Some key problems in hardware are discussed in this paper, including the design of C/V and R/V converted circuits, as well as how to design analog switches to reduce the coupling between dual-modal sensors. Reconstruction images based on Landweber iterative algorithm are in agreement with experiments and the system is verified stable and flexible.