A new apparatus of the melting point of gallium is developed in National Institute of Metrology. The melting point of gallium can be realized automatically by the fixed point furnace with the three-zone freezing and heating technique. The excellent stability and uniformity of the fixed point furnace is obtained because of the precise temperature control and the reasonable design. The cell of the gallium melting point is filled with the 99. 99999% purity gallium that is purified by the present technique and improved perfusion technique. The experiment results show that the plateau of the apparatus lasts more than 70 hours, and the difference of the plateau from 20% to 80% is less than 0. 15 mK. The reproducibility of the apparatus is 0. 07 mK,and the expanded uncertainty is 0. 36 mK(k =2).%介绍了中国计量科学研究院新型镓熔点自动复现装置,该装置的固定点炉采用半导体三段冻制及加热技术实现了镓熔点复现的自动化,通过精密控温及合理的结构设计获得优良的温度稳定性与均匀性.该装置镓熔点使用当前最新提纯技术的99.99999％高纯镓金属及完善的灌注技术.实验结果显示,该固定点装置温坪持续了70 h以上,前20％ ～ 80％温坪变化小于0.15 mK,复现性为0.07 mK,该装置的扩展不确定度为0.36 mK (k=2).
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