LNE has set up a new national standard in gas flowrate measurement between 0.2 mg·s-1 and 200 mg·s-1 of nitrogen or dry air to calibrate automatically Molbloc laminar flowmeters. This paper describes the metrological qualification of this standard based on the dynamic gravimetric method: optimization of the method to reduce the uncertainty by a factor of 2 compared to those obtained with the LNE old gravimetric benches, participation to an interlaboratory comparison to validate this result. The uncertainty calculation is developed up to the calibration of a Molbloc laminar flowmeter.

Key words

dynamic gravimetric method
reference bench