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Transport Properties of Argon at Zero Density From Viscosity-Ratio Measurements



E May, Michael R. Moldover, Robert F. Berg, John J. Hurly


We determined the zero-density viscosity and thermal conductivity of argon with an uncertainty of only 0.039 % in the temperature range 200 K to 400 K. Our results will improve: (1) the argon-argon interatomic potential, (2) calculated boundary-layer corrections for primary acoustic thermometry, and (3) calibrations of laminar flow meters as well as instruments for measuring transport properties. At 298.15 K, we determined the ratio = 1.13800 0.00018 from measurements of the flow rate of these gases through a quartz capillary of known dimensions and simultaneously measuring the pressures at the ends of the capillary. Between 200 K and 400 K, we used a two-capillary viscometer to determine = 1.21167 0.82034 exp(-T/123.78 K) with an uncertainty of 0.025 %. From , we computed using the values of calculated ab initio. Finally, we computed the thermal conductivity of argon from and values of the Prandtl number that we computed from argon-argon interatomic potentials.


ab initio calculations, argon, gases, helium, interatomic potential, Prandtl number, thermal conductivity, transport properties, viscosity


May, E. , Moldover, M. , Berg, R. and Hurly, J. (2006), Transport Properties of Argon at Zero Density From Viscosity-Ratio Measurements, Metrologia, [online], (Accessed May 22, 2024)


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Created March 31, 2006, Updated October 12, 2021