基于ECT系统的信号完整性分析

Analysis on signal integrity based on ECT system

为了进一步提高电学层析成像(ECT)采集系统的测量精度,分析研究了ECT信号的完整性对测量结果的影响。针对测量电容信号微弱、值在p F级别的特点,设计出一种考虑信号完整性的ECT采集系统,其传感器占空比为81%。利用上述系统来分析信号完整性对测量结果的影响。实验结果表明:当正弦激励信号的峰峰值为18.7 V时,采集到的最大信号经过电流/电压(C/V)转换后的电压峰峰值为921 m V,与理论计算结果基本吻合;运用灵敏度矩阵系数算法,在PC上得出了清晰的ECT图像。表明该测量系统满足精度要求。

In order to further improve measuring precision of electrical capacitance tomography（ ECT） acquiring system,analyze and research on effect of integrity of ECT signal on measurement results. Aiming at characteristics of weak measuring capacity signal,and the value is in p F level,an ECT acquisition system designed considering signal integrity,duty ratio of sensor is 81 %. Then,the above system is used to analyze the effect of signal integrity on measured results. Experimental results show that when the peak-to-peak value of sine excitation signal is18. 7 V,after current voltage（ C/V） conversion,the voltage peak-to-peak value of the collected biggest signal is921 m V,which is consistent with the theoretical calculation results; by using sensitivity matrix coefficient algorithm,clear ECT images are obtained on PC. The results show that the system meets the requirements of measurement precision of system.