摘要
电磁流量计输出的流速信号非常微弱,且常叠加共模干扰,经信号调理电路放大后,会导致信噪比很低,甚至淹没有用信号.针对这问题提出了利用前置放大电路有效抑制共模干扰,对其进行定性、定量分析,给出实际可行的提高差动放大电路输入阻抗的设计,并进行分析、推导和对比计算,证明其可以很大限度抑制共模干扰,提高测量准确度.
The common-mode interference is always interfused with the weak velocity signal of the electromagnetic flowmeter, which can be amplified by the signal processing circuit. This causes low signal-to-noise ratio and even submerge the velocity signal. The paper used the preamplifier to reject common-mode interference effectively.We did qualitative analysis and quantitative analysis. We also showed practical design which can improve the amplifier＇ s input impedence. Then we did analysis, deduction and contrast for it. Those proved the design can reject common-mode interference as much as possible and advance measurement accuracy.
出处
《哈尔滨理工大学学报》
CAS
北大核心
2009年第1期92-95,共4页
Journal of Harbin University of Science and Technology
基金
黑龙江省教育厅科学技术研究项目(10511100)
关键词
差动放大电路
共模干扰
输入阻抗
电磁流量计
differential amplifier
common-mode interference
input impedance
electromagnetic flowmeter
