液滴分析仪光电传感器的改进  

The Improvement of Droplet Analyzer Photoelectric Sensor

作　　者：姚尧[1] 裘祖荣[1] 樊玉铭[1] 

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《光电工程》2015年第5期75-81,共7页Opto-Electronic Engineering

基　　金：国家自然科学基金项目(51005165/E051102)

摘　　要：针对液滴分析仪光纤、电容传感器多次测量重复性不高,影响液滴分析测量精度的关键问题,重新设计了传感器结构,在电容环形极板外部增加屏蔽结构。采用数字电容信号测量法代替原有激励模拟测量方法,电容传感器测量极小值标准差为0.001 7 p F,极大值标准差为0.002 4 p F。改进光纤信号测量电路,利用无限增益低通滤波器避免由于放大倍率过高引起的自激震荡,光纤传感器测量峰值标准差为0.019 9 V,提高了液滴分析仪测量精度。For the key problem of droplet analyzer optical fiber and capacitance sensor poor measurement repeatability which impact droplet analysis measurement accuracy, the sensor structure was redesigned by increasing shielding structure in the external of capacitance sensor annular plate. Digital capacitance signal measurement method was used instead of excitation type analog measurement method. The minimum and maximum standard deviations measured by capacitance sensor are 0.001 7 pF and 0.002 4 pE The optical fiber signal measurement circuit was improved, and infinite gain low-pass filter was used which avoided self-excited oscillation caused by high magnification. The peak standard deviation measured by optical fiber sensor is 0.019 9 V, and the droplet analyzer accuracy is improved .

关 键 词：液滴分析技术 光纤传感器 电容传感器 AD7747 液滴指纹图 

分 类 号：TP206.1[自动化与计算机技术—检测技术与自动化装置] TH744.4[自动化与计算机技术—控制科学与工程]