采用电补偿方案的新一代立式计算电容装置

针对立式计算电容最大不确定度来源的端部效应误差,中国计量科学研究院经过多年改进,研制出的最优中空电补偿电极在计算电容模型装置上,没有采用加装钉子头进行补偿的电补偿方案,并完成了诸如端部效应误差的补偿效果、偏心效应误差等电气性能验证试验,成功应用在新一代立式计算电容装置上。实验结果表明,采用电补偿方案的新一代立式计算电容装置复现1 pF电容单位的相对标准不确定度为1.0×10^-8。

The New Vertical Calculable Cross-capacitor by Adoptingthe Novel Electrical Compensation Approach

To compensate the end effect error in a vertical calculable cross-capacitor(VCCC)with a fixed and a movable guard electrode,an electrical compensation approach is adopted by the National Institute of Metrology,China(NIM).After continuous improvements and modifications,the latest optimal hollow active auxiliary electrode(OHAAE)was developed,which was different from a nosepiece used by other national institutes of metrology in the world,and its electrical performances including the compensation effectiveness,eccentricity effect and so on were investigated on the NIM s model capacitor device.Instead of the nosepiece,the latest OHAAE was successfully applied and the relative standard uncertainty of the reproduction of 1 pF capacitance unit from the new NIM s VCCC was 1.0×10^-8.