一种(10^-1~10^-10)Pa·m3/s标准气体流量计的设计

Novel Standard Gas Flowmeter Covering (10^-1~10^-10) Pa·m/s Range:An Instrumentation Study

为了解决真空计量检测对标准气体流量的需求,设计出(10^-1~10^-10)Pa·m3/s的标准气体流量计。装置主要由定容法流量模块、流导法流量模块、供气与抽气模块、保温模块、控制模块组成,通过定容法和流量法提供标准气体流量。采用容积约为5和0.1 L的真空室作为定容室,同时为流导元件入口提供一定压力的气体;仅用两台电容薄膜真空计作为参考标准测量真空室气体压力,通过PLC触摸屏或计算机进行测量数据采集及运行控制;采用激光在铂金片上打孔并进行真空镀膜的工艺获得10^-10 m^3/s流导元件。设计的装置外形尺寸不超过500 mm×400 mm×500 mm,主体重量小于35 kg,提供的流量范围为(10^-1~10^-10)Pa·m3/s,具有成本低、操作方便、便携等优点。

A novel portable Standard Gas Flowmeter,covering(10^-1~10^-10)Pa·m^3/s range,weighing 35 kg,and 500 mm×400 mm×500 mm in size,has been successfully developed.Operating in constant volume and constant conductance flow modes,the flowmeter comprises:the programmable logic controller(PLC)touch-screen and/or host-computer,large(5 L)/small(0.1 L)vacuum chambers,constant volume/conductance flow modules,gas supply,and pumping/thermal-isolation/control units.The original work was the realization of 10^-10 m^3/s molecular flow conductance;specifically,the tiny orifice was fabricated by laser drilling and by film deposition on Pt-sheet.Two capacitance diaphragm gauges were used as the reference standards in pressure measurement of the vacuum chambers.We suggest that the newly-designed portable Standard Gas Flowmeter be of much economic impact because of great market demand,wide measurement range,easy operation,high-level of automation,lightweight and low cost.