An additional uncertainty of the throughput generated by the constant pressure gas flowmeter
Year: 2008
Type: conference-paper
Abstract: The lower range limit of constant pressure gas flowmeters is about 10 −8 Pa × m 3 /s. Detrimental gas throughputs caused by leaks and gassing from surfaces prevent from its decrease. Even if the flowmeter is entirely vacuum tight the throughput caused by the outgassing from surfaces can be sufficiently reduced only by pumping at elevated temperature. It can be performed with the flowmeters using directly driven bellows or diaphragm bellows in the volume displacers. Despite it, the lower range limit can hardly be decreased more than several ten times with up to now known designs. An additional uncertainty caused by the difference in pressure at the initial and final instant of measurement will increase at generating small throughputs to the extent that it will kill the measurement.
Institutions: Charles University, Český metrologický institut
Language: English
Subfield: Instrumentation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W2076574209