Take a sneak peek at the new NIST.gov and let us know what you think!
(Please note: some content may not be complete on the beta site.).
NIST Authors in Bold
|Author(s):||Allan H. Harvey; Mark O. McLinden; Weston L. Tew;|
|Title:||Thermodynamic Analysis and Experimental Study of the Effect of Atmospheric Pressure on the Ice Point|
|Published:||September 24, 2013|
|Abstract:||We present a detailed thermodynamic analysis of the temperature of the ice point as a function of atmospheric pressure. This analysis makes use of accurate international standards for the properties of water and ice, and of available high-accuracy data for the Henry‰s constants of atmospheric gases in liquid water. The result is an ice point of 273.150 02 K at standard atmospheric pressure, with higher ice-point temperatures (varying nearly linearly with pressure) at lower pressures. The effect of varying ambient CO2 concentration is analyzed and found to be significant in comparison to other uncertainties in the model. The thermodynamic analysis is compared with experimental measurements of the temperature difference between the ice point and the triple point performed at elevations ranging from 145 m to 4302 m, with atmospheric pressures from 101 kPa to 60 kPa.|
|Proceedings:||Proceedings of the 9th International Temperature Symposium|
|Dates:||March 19-23, 2012|
|Keywords:||fixed point, Henry's law, ice point, pressure, thermometry|
|PDF version:||Click here to retrieve PDF version of paper (310KB)|