镓熔点温坪复现研究  

Study on the Realization of Gallium Melting Point Plateau

作　　者：李利峰 李锐[1] 闫小克[2] 王宁 何沛 LI Li-feng;LI Rui;YAN Xiao-ke;WANG Ning;HE Pei(Beijing University of Civil Engineering and Architecture,Beijing 100044,China;National Institute of Metrology,Beijing 100029,China;University of Science&Technology Beijing,Beijing 100083,China)

机构地区：[1]北京建筑大学,北京100044 [2]中国计量科学研究院,北京100029 [3]北京科技大学,北京100083

出　　处：《计量学报》2020年第4期419-424,共6页Acta Metrologica Sinica

基　　金：国家重点研发计划(2017YFF0205901)。

摘　　要：镓熔点是ITS-90国际温标中重要的定义固定点,在温度计量研究中起着重要作用。由于高纯镓从液态转化为固态时,体积膨胀约3.1%,传统玻璃外壳的镓熔点容器在冻制过程中很容易造成损坏。为了解决这一难题,设计了一种具有金属外壳的镓熔点装置,以该装置为对象,开展了2种不同镓熔点复现方法和2种不同复现装置对镓相变温坪影响方面的研究,并与国外同类型装置的性能进行了比较。实验结果表明:不同镓点容器复现的镓熔点温度在0.02 mK范围内一致,高纯镓中的微量杂质是造成差异的主要原因;外液-固界面复现方法比双液-固界面复现方法得到的温坪值低0.09 mK;不同复现装置对镓熔点温坪的影响较小。The gallium melting point is an important defining fixed point in the International Temperature Scale of 1990(ITS-90)and plays a crucial role in temperature measurement researche.When the phase transition of the high-purity gallium from the liquid state to the solid state happens,the volume expansion is about 3.1%,which can result in the rupture of the conventional glass container of the gallium point cells during the freezing process.In order to solve this problem,a gallium melting point device was developed with a metal shell.Effects of realization methods and devices on the gallium melting plateaus were carried out.At the same time,a comparison was conducted between a similar foreign device and the developed cell.The experimental results showed that the temperature difference of the temperatures of the gallium melting point was consistent within of 0.02 mK,which may be attributed to the trace impurities in high-purity gallium samples.The temperature of gallium melting point realized with the outer liquid-solid interface method was 0.09 mK lower than that of the temperature obtained by the two-liquid-solid interface method.Effects of the realization apparatus on the gallium melting plateaus were small.

关 键 词：计量学 ITS-90 镓熔点容器 复现方法 熔化温坪 自热和静压修正 杂质影响 

分 类 号：TB942[一般工业技术—计量学]