Characterization of a vacuum pressure standard based on optical refractometry using nitrogen developed at NIM
Characterization of a vacuum pressure standard based on optical refractometry using nitrogen developed at NIM
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DOI：
10.1016/j.vacuum.2021.110598
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发表时间：
2021-09-17
期刊：
影响因子：
4
通讯作者：
Sun, Jianping
中科院分区：
文献类型：
--
作者：
Yang, Yuanchao;Rubin, Tom;Sun, Jianping
国家计量研究所（NIM）基于使用氮气的光学折射法开发了称为光学压力标准（OPS）的真空压力标准。OPS由一个由超低膨胀玻璃制成的双FabryPe急性加重腐蚀（FP）腔、一个容纳FP腔的铜腔、一个温度控制系统和一个光学系统组成。两个波长为633 nm的可调谐二极管激光器被频率锁定到测量腔和参考腔，并且它们的频率被用于感测铜室内的压力。研究了FP腔的热膨胀系数和蠕变效应。铜室的温度均匀性评估在1 mK内。阐明了所谓的热岛效应，并避免了所有的测量，并考虑了放气和泄漏的影响。观察到参考腔的变形的非线性和滞后行为。OPS和NIM主活塞压力计之间的直接比较表明，在20 kPa至100 kPa范围内评估的压力偏差不超过百万分之10。OPS的不确定度为[（0.13 Pa）2 +（23.10- 6 p）2]0.5（k = 2）。
A vacuum pressure standard called an optical pressure standard (OPS) has been developed at the National Institute of Metrology (NIM) based on optical refractometry using nitrogen gas. The OPS consists of a dual FabryPe acute accent rot (FP) cavity made from ultra-low expansion glass, a copper chamber housing the FP cavity, a temperature control system, and an optical system. Two tunable diode lasers at a wavelength of 633 nm were frequencylocked to the measurement cavity and the reference cavity, and their frequencies were used to sense the pressure within the copper chamber. The performance of the FP cavity was investigated including the coefficient of thermal expansion and creeping effects. The temperature uniformity assessed for the copper chamber was within 1 mK. The so-called heat-island effect was elucidated and avoided for all measurements performed, and the influence of outgassing and leakage was considered. Non-linear and hysteresis behavior was observed for the deformation of the reference cavity. A direct comparison between the OPS and the NIM primary piston gauge showed no deviations greater than 10 parts per million for the pressures assessed in the range from 20 kPa to 100 kPa. The uncertainty of the OPS was evaluated to be [(0.13Pa)2 + (23.10-6p)2]0.5(k = 2).