Electrical potential and electrical field distribution of square electrical capacitance tomography

Abstract

Electrical Capacitance Tomography (ECT) system helps user to understand the flow distribution inside the close pipe by detecting the variation of permittivity distribution in the inspection area. Generally, most reported ECT systems are implemented to circular shape pipe only. However, square shape pipes are sometimes found in power industry and chemical reactor, therefore this paper is studying the electrical distribution of ECT system within a square pipe. ECT is able to provide fast response, low cost and non-radiation system but similar to all other electrical tomography system, ECT suffers from soft-field effect. This paper proposes segmentation excitation to overcome this problem. Segmentation excitation applies when more than one electrode excited at one time. This paper focuses Protocol 2 or 2-electrode excitation for 8-electrode square ECT system. The simulation was done by using COMSOL Multiphysics. The images of the excitations are presented in this paper. The electrical potential is recorded at the center of the system to analyses the strength of the electrical potential. In addition for square ECT system, the corner configuration provides 3.40% higher electrical potential compared to side excitation configuration.