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本文介绍了计量院研制的新型结构的镓三相点容器及镓三相点的复现方法。并将两个镓三相点容器与镓熔点容器进行了比对 ,结果表明 :两个镓三相点容器所复现的镓三相点温度与镓熔点温度的差值分别为1 85mK、1 71mK ;通过分析认为镓三相点容器间的温差 (0 1 4mK)主要是镓样品所含杂质成分的差异引起的。 相似文献
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《计量技术》2016,(9)
汞三相点(-38. 8344℃)是ITS-90国际温标重要的定义固定点之一。为提高汞三相点复现水平,实现-38. 8344~29. 7646℃海水温度的高精度测量,满足海水温度校准需求,开展了汞三相点研究。本文介绍了金属外壳的汞三相点容器及热管自动复现装置、汞三相点的复现过程及测量结果。实验结果表明:热管汞点复现装置可高精度复现汞三相点。采用测量精度为0. 2×10~(-6)的1594A测温电桥时熔化温坪稳定后19小时温度变化小于0. 2mK。采用测量精度为0. 02×10~(-6)的6622A-XPS测温电桥时,18小时内的汞点熔化温坪变化小于0. 1mK。因此,汞点复现水平与测量电桥的精度有关。 相似文献
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介绍了微型镓基共晶固定点的灌注工艺和准绝热相变特性测量系统;结合空腔黑体和非近位安装的温度传感器,研究了Ga-Sn和Ga-Zn共晶固定点的相变温坪重复性和Ga固定点的相变温坪长期稳定性;通过特定的热环境下镓及2个镓基共晶固定点三者熔化过程中温度传感器测量到的相变温坪值,对嵌入空腔黑体底部的温度传感器进行校准,其校准结果与实验室常规校准方法得到的结果差异均小于2mK。实验结果表明:在热环境保持不变的条件下,随着相变时间的增加,相变温坪值就越靠近理论上相变物质的熔化温度,即固定点与温度传感器测孔之间的异位温差越小;对于Ga-Sn和Ga-Zn共晶固定点,温度传感器测量到的相变温坪值与加热功率呈线性关系,零功率下的单点校准温度分别为20.352℃和25.187℃。 相似文献
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The triple point of gallium has been realized by a calorimetric method using capsule-type standard platinum resistance thermometers
(CSPRTs) and a small glass cell containing about 97 mmol (6.8 g) of gallium with a nominal purity of 99.99999%. The melting
curve shows a very flat and relatively linear dependence on 1/F in the region from 1/F = 1 to 1/F = 20 with a narrow width of the melting curve within 0.1 mK. Also, a large gallium triple-point cell was fabricated for the
calibration of client-owned CSPRTs. The gallium triple-point cell consists of a PTFE crucible and a PTFE cap with a re-entrant
well and a small vent. The PTFE cell contains 780 g of gallium from the same source as used for the small glass cell. The
PTFE cell is completely covered by a stainless-steel jacket with a valve to enable evacuation of the cell. The melting curve
of the large cell shows a flat plateau that remains within 0.03 mK over 10 days and that is reproducible within 0.05 mK over
8 months. The calibrated value of a CSPRT obtained using the large cell agrees with that obtained using the small glass cell
within the uncertainties of the calibrations. 相似文献
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I. Yang C. H. Song K. H. Kang Y. -G. Kim K. S. Gam 《International Journal of Thermophysics》2008,29(5):1740-1748
A system was fabricated to realize the triple point of argon for the calibration of long-stem standard platinum resistance
thermometers. A cryostat was constructed so that the temperature could be controlled quasi-adiabatically, and the melting
was realized using the continuous-heating method. The combined uncertainty of the realization of the triple point of argon
for a confidence level of 95% was 0.6 mK. 相似文献
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X. P. Hao J. P. Sun C. Y. Xu P. Wen J. Song M. Xu L. Y. Gong L. Ding Z. L. Liu 《International Journal of Thermophysics》2017,38(6):90
Miniature Ga and Ga–In alloy fixed points as temperature standards are developed at National Institute of Metrology, China for the in situ calibration of temperature sensors. A quasi-adiabatic vacuum measurement system is constructed to study the phase-change plateaus of the fixed points. The system comprises a high-stability bath, a quasi-adiabatic vacuum chamber and a temperature control and measurement system. The melting plateau of the Ga fixed point is longer than 2 h at 0.008 W. The standard deviation of the melting temperature of the Ga and Ga–In alloy fixed points is better than 2 mK. The results suggest that the melting temperature of the Ga or Ga–In alloy fixed points is linearly related with the heating power. 相似文献