Abstract:
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.