Design of Low Capacitance Measurement Circuit and the Determination of Parameters Based on the Principle of Phase Sensitivity Demodulation

It is one of the keys to how to eliminate noises and the difficulty of the low capacitance measurement because there is a difference of about two levels between the capacitance values and coupling capacitance for ECT. The object of this paper majors in the research of 12-electrode oil-water two-phase flow ECT system, the data acquisition system is designed and the AC signals demodulated by using the principle of phase sensitivity demodulation based on analyzing principle of measurement in the ECT system. The in the measuring process is discussed and parameters of measurement circuit are chosen. The experiment results show that the sensitivity of circuit 0.49974V/pF, non-linear error is 0.2630% and static measurement error is 0.248%. So the method practical and the measurement of the low capacitance is more accurate.
electrical capacitance tomography phase sensitivity demodulation low capacitance measurement noises error analyses
CHEN Deyun HAN You HUANG Jiading TANG Wenming YU Xiaoyang
Harbin University of Science and Technology, Harbin, 150080
国际会议
北京
英文
2007-08-05(万方平台首次上网日期,不代表论文的发表时间)