β 射线电离气体流量测量研究  

Investigation on radioactive rays ionization gas flowmeter

作　　者：曲义坤[1,2] 周立业[1,2] 苗齐田 吴志芳[1,2] 向新程 魏任之[1,2] 

机构地区：[1]清华大学核能技术设计研究院 [2]中国矿业大学机械系

出　　处：《清华大学学报（自然科学版）》1997年第5期54-57,共4页Journal of Tsinghua University(Science and Technology)

摘　　要：研究射线电离标记气体测流速，可为现场提供新的计量方法。利用计算机调制使β射线脉冲穿过流经的气体，形成分离的离子团，并记下离子团生成时刻，而后利用在气体流动方向下游布置的传感器探测离子团的到来，即可得到气体传播一段距离所需的时间，因而就可求得气体的流速。本文导出了电机调制离子团尺寸及极板偏压的计算公式。采用平行于射线入射方向的新型传感器结构，可以提高离子探测效率，减小测量误差。经实验，该种新型流量测量系统既具有较高的测量精度，可达到２％，又具有一定的抗干扰及污染能力。A microcomputer controlling gas flow velocity measuring system based on the detection of the gas ionized by β rays is presented. A detector with the ion collecting plate parallel to the radioactive rays has proven effective in the collection of ions. The ion cloud outline modulated by a step motor has been described with its size calculation formula presented; the basic control relation for the main parameters to maintain high measuring precision has been proposed; the necessary voltage needed for the effective collection of the ions has been derived. It is due to the configuration of the detecting plates that the precision of this ion detection gas flow device is around 2% and is reliably resistant to dust and moisture after several days operation in laboratory. The timing error caused by amplitude fluctuation is diminished by the peak searching signal processing method utilized.

关 键 词：气体 流量测量 放射线电离 离子探测 β射线电离 

分 类 号：TH814[机械工程—仪器科学与技术] TL811[机械工程—精密仪器及机械]