Development of a displacement current-based sensor for electrical capacitance tomography applications

This paper presents the development of an Electrical Capacitance Tomography sensor, allowing for the reconstruction of the permittivity distribution in a piping system. Two suitable front-end circuit concepts for the sensor are investigated — one is based on the measurement of displacement currents and the other on electrode potential measurement. Input stage circuit models are used to analyse the robustness against stray capacitances, indicating clear advantages of the displacement current-based approach. Hence, a further examination of this concept is carried out, including the hardware design and the development of the front-ends. For the entire tomography sensor, applied image reconstruction methods, and measurement results are presented in this paper.