计算电容屏蔽电极位移测量的不确定度评估  

Uncertainty Evaluation on Displacement of Blocking Electrodes in Calculable Capacitor

作　　者：王建波[1] 殷聪[1] 钱进[1] 刘忠有[1] 黄璐[1] 杨雁[1] 陆祖良[1] WANG Jian-bo;YIN Cong;QIAN Jin;LIU Zhong-you;HUANG Lu;YANG Yan;LU Zu-liang(National Institute of Metrology,Beijing 100029,China)

机构地区：[1]中国计量科学研究院,北京100029

出　　处：《计量学报》2022年第4期437-444,共8页Acta Metrologica Sinica

基　　金：国家重点研发计划(2016YFF0200302,2016YFF0200105)。

摘　　要：计算电容是电学阻抗单位复现的基准装置,是电容、电感和交流电阻的溯源依据。它是电磁计量领域内除量子电压、量子电阻基准之外准确度最高的装置。计算电容装置实现微小电容值(0.2至0.6 pF)精确测量的关键在于对其屏蔽电极位移的高准确度测量。从计算电容屏蔽电极位移测量的基本原理出发,系统分析了屏蔽电极位移测量结果的影响因素,具体包含Fabry-Perot干涉仪的锁定、稳频激光波长的实时校准、残余气体折射率影响、测量余弦误差以及Gouy相位修正,结合计算电容测量结果的复现性,得到屏蔽电极位移测量的相对标准不确定度为4.7×10^(-9)。The calculable capacitor is a classical and fundamental experiment apparatus in precise electromagnetic measurements.It is followed the‘new’electromagnetic principle which is firstly introduced by Lampard D G and Thompson A E.The calculable capacitor is the AC impedance primary standard,and it s the traceable source of the capacitance,inductance and AC impedance.It is a high-accuracy(at the level of 10^(-8))apparatus surpassed only by the quantum Josephson voltage and quantum Hall resistance experiments in the electromagnetic metrological field,and it is expected to reach the level of 10^(-9) through continual improvements and optimizations to improve the uncertainty level of electromagnetic metrology.The basic principle of the displacement measurement in calculable capacitor is presented,and impact factors,including Fabry-Perot interferometer locking,laser wavelength,residual index of refraction of air,cosine error and Gouy phase correction,are analyzed.Combining the repeatability of capacitance produced by calculable capacitor,a relative standard uncertainty of 4.7×10^(-9) is obtained.

关 键 词：计量学 计算电容 位移测量 锁定干涉仪 不确定度评估 屏蔽电极 

分 类 号：TB971[一般工业技术—计量学]