Abstract The vertical temperature uniformity of the fixed-point furnace is an important factor affecting the plateau quality of the fixed-points of the International Temperature Scale of 1990 (ITS-90). In order to improve the reproducibility of the aluminum freezing point, a three-zone temperature-controlled fixed-point furnace was designed, and the aluminum fixed point cell with a metal shell was used to study the vertical temperature uniformity and its influencing factors. On this basis, the continuous heat flux method was adopted to precisely realize the aluminum freezing point. The experimental results show that the temperature uniformity can be improved by adjusting the settings of the top, middle, and bottom furnace temperatures, and the temperature stability of the freezing plateau within 4 hours is less than 1mK. The phase transition supercooling of the high purity aluminum is approximately 0.14℃ under the experimental conditions.
HE Pei,LIN Lin,YAN Xiao-ke, et al. Study on the Realization of Aluminum Freezing Point in the Three-zone Temperature Controlled Fixed Point Furnace[J]. Acta Metrologica Sinica, 2021, 42(3): 321-326.
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