电容层析成像系统三维传感器结构分析

Analysis of Three-Dimensional Sensor Structure in Electrical Capacitance Tomography System

针对电容层析成像系统存在检测信号微弱,灵敏度低和信噪比低等问题,在分析传感器结构参数对传感器物理性能影响的基础上,给出了一种三维电容层析成像系统传感器模型的选择和分析方法,该方法以6种常用模型为基础,通过对比空满管电容值分析,并通过试验改变屏蔽罩厚度dl,极板张角θ,层间旋转角α的值,分析电容值随参数的变化,绘制电容值随参数的变化曲线,给出了三维ECT传感器参数的参考值.屏蔽罩厚度dl的参考值为8~12 mm,极板张角θ的参考值为50~54°,层间旋转角α的参考值为45°,为三维ECT传感器设计提供了新思路.

For electrical capacitance tomography system, there are some disadvantages such as weak detected signal, low sensitivity, low signal to noise ratio （SNR） and so on. Based on the analysis of the influence on physi- cal properties from sensor structure parameters, a method of selection and analysis for three-dimensional sensor model are put forward. Based on 6 common models and the analysis of empty-pipeline and full-pipeline electrical capacitance values, in the experiment with the adjustment in the parameters of shield thickness, electrode angle and rotation angle between layers, the differences of electrical capacitance values are analyzed, and the curve of ca- pacitance value is plotted along with the parameters. In this method a set of parameters for three dimensional ECT sensor are computed as follows： the referent value scope of shield thickness is between 8 ~ 12 mm, the referent val- ue scope of electrode angle is between 50 ~ 54°, and the referent value of rotation angle between layers is 45°, which supplies a novel idea for the design of three dimensional ECT sensor.