基于质量流量控制器的高精密配气系统

High Precision Gas Distribution System Based on Mass Flow Controller

针对市售标气很难满足实际应用需求的问题,基于质量流量控制器的控制原理,研制一套高精密动态可持续输出的配气系统。给出系统的总体结构及其工作原理,并利用电化学传感器和统计学原理,对该系统的稳定性和准确度进行了考察,结果表明:在30min的考察期内,配气浓度标准偏差小于0.40%,在95%的置信区间内与电化学传感器测定值的准确度相当。

Considering the commercially-available standard gas' difficulty in satisfying practical application and basing on control principle of the mass flow controller,a high-precision gas distribution system was developed to export gas continuously; and the system's overall structure and working principle were presented and both electrochemical transducer and principle of statistics were applied to investigate into system's stability and accuracy. The results show that in a 30min-long period,the gas concentration's standard deviation becomes less than 0. 40% and at a 95% confidence interval,it has accuracy same as the electricity chemical sensor.