New generation sealed cells have been developed at AIST, which are used for realization of low temperature fixed points of the International Temperature Scale of 1990. The triple point of equilibrium hydrogen (e-H₂), one of the fixed points, is realized using the sealed cells containing ferric oxy-hydroxide as a catalyst for the ortho-para equilibration. The reduction of the amount of the catalyst suppresses a heat-capacity anomaly due to an interaction between hydrogen and catalyst at temperatures just below the triple point and allows one to obtain more reliable melting curves for e-H₂.
references
[1]Nakano T., Tamura O. and Sakurai H., in: Temperature, its Measurement and Control in Science and Industry, Vol. 7, 2003, American Institute of Physics, (in press).
[2]Nakano T., Tamura O. and Sakurai H., T. SICE 38, 2002, pp. 947-951.
[3]Nakano T., Tew W., Tamura O. and Sakurai H. in Proceedings of 15^th Symposium on Thermophysical Properties, 2003, Boulder (to be submitted).
[4]Nakano T., Tamura O. and Sakurai H., in Proceedings of 2^nd International Seminar on Low Temperature Thermometry, 2003, Wolclaw (to be published).

Relational Information