An analysis of sensitivity distribution using two differential excitation potentials in ECT

Abstract

The investigation of this work is to analysis the sensitivity distributions using two differential excitation potentials, in order to improve the situation of: (1) non-uniform sensitivity distribution: (2) less sensitivity in the central area and (3) non-linear change in ECT (Electrical Capacitance Tomography) system. Simulation using COMSOL Multiphysics is developed in order to obtain the changes in capacitance inter-electrodes and the permittivity of the dielectric material when two differential excitation potentials were injected. The MATLAB simulation is used to obtain the sensitivity distribution inside the closed pipe from the sensor. Generated phantoms and measured values are presented. Simulation is verified using available experimental data through the existing system, 16- segmented ECT sensor electrodes by PROTOM Research Group UTM, MALAYSIA. By using this technique the linear relationship between the capacitances measured to inter-electrodes and the permittivity dramatically improved and the sensitivity distribution for an opposing electrode pair was increased thus gives the sensitivity distribution in the central area increased. The use of this technique does increase the level of detection signals and the SNR(signal noise to ratio) compared to those achieved using standard single-voltage source method.