Research On Electrical Capacitance Tomography Sensor Structure Emulating And Detecting System

Measuring the parameters of two-phase flow is important in the industrial production and scientific research. As a rapidly developed measuring method, Process Tomography (PT) technique has some achievements in measuring the parameters distributing of two-phase flow. PT technique provides novel means of visualizing the internal behavior of industrial processes. The tomographic images produced by PT system provide valuable information for the assessment of equipment designs and the on-line monitoring of industrial processes.Electrical Capacitance Tomography (ECT) is one of the techniques, which is firstly developed for PT. It has low-cost, high-speed, robust and non-intrusive. In this paper the ECT sensor structures and the data acquisitions system for ECT have been studied.1 The sensor model was built by analyzing ECT sensor structure. To obtain the disciplinarian of configuration parameters and operation way to influence of ECT sensor performance by finite emulating. Configuration parameters and operation way included the electrode angle 0, the thickness of pipe wall (R2-R1), the relative permittivity value of pipe wall (epw), the thickness of screen layer (R3-R2), the relative permittivity value of screen layer (es), combined electrode and uncombined electrode and floating electrode and non-floating electrode. The configuration parameters of given pipe based on the disciplinarian.2 The data acquisition system adopted the charge / discharge capacitance measuring circuit. This paper described the charge/discharge circuit and data acquisition. The data acquisition system used the DC offset compensation method to balance both the standing capacitance and the charge injection capacitance. To increase the overall data acquisition speed, parallel measurement channels were used. Because of wide dynamic range of measurement, a self-optimizing digital-control gain amplifier was presented tosatisfy the different sensitivity requirements. The gain amplifier also can increase the data acquisition speed at the same time. Lastly, the paper gave some suggestion for future study.