Abstract:

A new sensor structure based on the non-contact way to detect flammable and explosive substances is presented. The working principle of the designed sensor is to measure the change in capacitance between electrodes pair under different conditions to calculate electrical permittivity of measured material. The structure, geometry and size of the ECT sensor are discussed. The sensor performances are analysed and compared. COMSOL simulation software is used to evaluate the performance of two types of designed sensor. An impedance analyzer is used to measure the capacitance between each electrode pair. Through the analysis of the result, the resolution and sensitivity of the designed ECT sensor are better than those of Planar capacitance sensors, which provides an experimental foundation for the future research work,image reconstruction of the liquid in a sealed container.

Key words: ECT(electrical capacitance tomography) sensor, impedance analysis, liquid permittivity, planar capacitance sensor array