TITLE:
Modeling and Implementation of AC Electrical Capacitance Tomography
AUTHORS:
K. Manikandan, S. Sathiyamoorthy
KEYWORDS:
Electrical Capacitance Tomography, ANSYS, Lab VIEW, Embedded System, AC Signal
JOURNAL NAME:
Circuits and Systems,
Vol.7 No.11,
September
19,
2016
ABSTRACT: Electrical Capacitance Tomography (ECT) determines the dielectric
permittivity of the interior object depending on the measurements of exterior
capacitance. Generally, the electrodes are placed outside the PVC cylinder
where the medium to be imaged is present; but in ECT using inter-electrode
capacitance measurements can be achieved by placing inside of the dielectric
medium. In the proposed ECT system, the ECT sensor is modeled using ANSYS
software and the model is implemented in real ECT system. For each step of
measurement, a stable AC signal is applied to a pair of electrodes that form a
capacitor. The novel system is to measure the capacitance range variation in
picofarad and the corresponding voltage rangesfrom 1volt to 4volts. The switching speed of all combinational electrodes is
implemented using embedded system to achieve higher speed performance of AC ECT
system which eliminates the drift and stray capacitance error. This is yielding
the original image of unknown multiphase medium inside the electrodes using Lab
VIEW. This paper investigates several advantages such as improved overall
system performance; simple structure, avoids stray capacitance effect, reduces
the drift problem and achieves high signal to noise ratio.