微小电容测量仪500fF/1MHz溯源方法研究

fF量级高频微小电容测量在军工电子产品领域有着重要作用,针对微小电容测量仪500fF/1MHz点无法溯源的现状,研制了惰性气体封装的500fF高频标准电容器作为传递标准。建立高频小电容测量模型,基于“反算法”估算出500fF高频标准电容器分布参数,称作“理论推导”溯源方案,不确定度优于0.15%;利用3台同等量级的高频微小电容测量传递标准,称作“计量比对”溯源方案,不确定度优于0.07%。利用以上2种方案对同1台仪器开展溯源,实验数据结果基本一致,能够满足用户使用要求,为更低容值、更高频率的微小电容的溯源提供了可参考的路径。

Research on Traceability Method of Micro Capacitance Measuring Instrument at 500fF/1MHz

Micro capacitance measuring instrument in fF level has an important role in Military electronic products.In order to solve the no traceability problem of micro capacitance measuring instrument at 500fF/1MHz, a high frequency 500fF standard capacitor encapsulated with inert gas was manufactured as transfer standard.A measurement model of micro capacitance with high frequency was established, and the distributed parameter was estimated using “subjunctive” method.In the end, the uncertainty of a traceability method called “theoretical deduction” achieves 0.15%.Using three micro capacitance measuring instruments in the same level, the uncertainty of a traceability method called “measurement comparison” achieves 0.07%.The two kinds of traceability methods were used to calculate the same instrument, and the test results showed the same effect, which can satisfy users requirements.The above two traceability methods give an effective way for micro capacitance measurement in high frequency with lower capacitance.