Effect of Impurities on the Triple Point of Water: Experiments with Doped Cells at Different Liquid Fractions
Recent international comparisons showed that there is still room for improvement in triple point of water (TPW) realization uncertainty. Large groups of cells manufactured, maintained and measured in similar conditions still show a spread in the realized TPW temperature that is larger than the best measurement uncertainties (25 µK). One cause is the time-dependent concentration of dissolved impurities in water. The origin of such impurities is the glass/quartz envelope dissolution during a cell lifetime. The effect is a difference in the triple point temperature proportional to the impurities concentration. In order to measure this temperature difference and to investigate the effect of different types of impurities, we manufactured doped cells with different concentrations of silicon (Si), boron (B), sodium (Na) and potassium (K), the glass main chemical components. To identify any influence of the filling process, two completely independent manufacturing procedures were followed in two different laboratories, both national metrology institutes (VSL, Netherlands and UME, Turkey). Cells glass and filling water were also different while the doping materials were identical. Measuring the temperature difference as a function of the liquid fraction is a method to obtain information about impurities concentrations in TPW. Only cells doped with 1 µmol·mol−1 B, Na and K proved to be suitable for measurements at different liquid fractions. We present here the results with related uncertainties and discuss the critical points in this experimental approach.
KeywordsFrozen fraction Impurities Liquid fraction Raoult’s law Water triple point cells
This work was partly supported by the European Metrology Research Programme (EMRP) project “Novel Techniques for Traceable Temperature Dissemination, NOTED”.
- 1.M. Stock, S. Solve, D. del Campo, V. Chimenti, E. Méndez-Lango, H. Liedberg, P.P.M. Steur, P. Marcarino, R. Dematteis, E. Filipe, I. Lobo, K.H. Kang, K.S. Gam, Y.-G. Kim, E. Renaot, G. Bonnier, M. Valin, R. White, T.D. Dransfield, Y. Duan, Y. Xiaoke, G. Strouse, M. Ballico, D. Sukkar, M. Arai, A. Mans, M. de Groot, O. Kerkhof, R. Rusby, J. Gray, D. Head, K. Hill, E. Tegeler, U. Noatsch, S. Duris, H.Y. Kho, S. Ugur, A. Pokhodun, S.F. Gerasimov, Metrologia 43, 03001 (2006)ADSCrossRefGoogle Scholar
- 2.K.D. Hill, Triple point of water cells and the solubility of borosilicate glass, in TEMPMEKO 1999 Proceedings, pp. 68–73Google Scholar
- 4.G.T. Furukawa, W.R. Bigge, Reproducibility of Some Triple Point of Water Cells Temperature—Its Measurement & Control in Science & Industry, Vol. 5 (1982)Google Scholar
- 6.D.R. White, C.J. Jones, T.D. Dransfeld, R.S. Manson, Dissolved glass in triple-point-of-water cells, in Proceedings of TEMPMEKO 2004, pp. 313–318Google Scholar
- 8.M.J. de Groot, N. Lacroes, J.F. Dubbeldam, On the production of water triple point cells, in Proceedings of TEMPMEKO 2001, 8th International Symposium on Temperature and Thermal Measurements in Industry and Science, ed. by B. Fellmuth, J. Seidel, G. Scholz (VDE Verlag, Berlin, 2002), pp. 459–464Google Scholar
- 10.A. Uytun, A. Kartal Dogan, S. Ugur, Construction and characterization of the UME made water triple point cells, in Proceedings XVII IMEKO World Congress, June 22–27, 2003, Dubrovnik, CroatiaGoogle Scholar
- 13.A. Peruzzi, M. Dobre, G. Strouse, J. van Geel, C. Davis, Dilution of impurities in water triple point cells, in Proceedings of Ninth International Temperature Symposium, Los Angeles, Temperature: Its Measurement and Control in Science and Industry, Vol. 8, ed. by C.W. Meyer, A.I.P. Proceedings 1552 (AIP, Melville, NY, 2013), pp. 215–220Google Scholar
- 14.A. Peruzzi, M. Dobre, J. van Geel, M. Maeck, A re-sealable triple point of water cell for doping experiments with chemical impurities. TEMPERATURE 2015 21–24 April 2015 Saint Petersburg (Russia)Google Scholar