John Wright 1, Bodo Mikan 2, Richard Paton 3, Kyung-Am Park 4, Shin-ichi Nakao 5, Khaled Chahine 6 and Roberto Arias 7
1
National Institute of Standards and Technology, USA
2
Physikalisch Technische Bundesanstalt, Germany
3
National Engineering Laboratory, UK
4
Korea Research Institute of Standards and Science
5
National Metrology Institute of Japan
6
National Measurement Institute of Australia
7
Centro Nacional de Metrología, Mexico
John Wright et al 2007 Metrologia 44 07008
A key comparison between seven national metrology institutes in the area of low-pressure gas flow was organized by the Comité International des Poids et Mesures (CIPM) and the Working Group for Fluid Flow. A set of eight critical flow venturis with dedicated, redundant pressure and temperature sensors was used as the transfer standard at flows between 4.4 g/min and 260 g/min. Preliminary testing in the pilot lab determined temperature operating bounds and corresponding uncertainties. The transfer standard contributed a standard uncertainty of <0.026% to the comparison, primarily due to environmental temperature effects, the pressure sensors, and gas properties (the critical flow function and molecular mass of moist air). Redundant measurements by the transfer standard and the star pattern testing were valuable for maintaining low transfer standard uncertainty. The results supported equivalence between the labs with the largest difference between any two participants at any of the flows tested being 0.308%.
Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.
The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
Issue 1A ( 1 January 2007)
John Wright et al 2007 Metrologia 44 07008
J E Decker et al 2007 Metrologia 44 04001
Dionisio Hernández et al 2007 Metrologia 44 01011
Otto Jusko et al 2006 Metrologia 43 04006
Kurt Weyand 2005 Metrologia 42 01006
W Sabuga et al 2005 Metrologia 42 07005
Kenichi Fujii et al 2006 Metrologia 43 07007
Jong S Paik et al 2007 Metrologia 44 07005
A Gosset and T Madec 2005 Metrologia 42 07003
H-J von Martens et al 2003 Metrologia 40 09001