Calibration and uncertainties in gas microflow measurement in the range of 2–200 µg s−1 of nitrogen

Today the field of chemistry needs calibration in gas microflow measurement for applications such as thin film deposition, catalysis or the automotive industry. Few European metrology laboratories conduct this type of calibration. In France no laboratory can calibrate below 20 µg s−1. To meet this growing need, LNE has developed a calibration bench using the method of 'traced gas' in the range of 2–200 µg s−1. The method and the uncertainty estimation of the calibration bench and calibration results of three laminar flowmeters of Molbloc type and industrial flowmeters are presented in this paper