在电磁计量和仪器仪表行业中,通常需要高稳定电容标准器装置对仪器设备进行量值检定校准以确保它们测量的准确性。可选择型低值电容就是一种可在同一系统中输出不同稳定微小电容值的标准器。针对该类电容器最大不确定度来源之一,即屏蔽栅通孔的边缘效应,文中采用3-D电场仿真对其进行了深入研究分析,同时依据仿真结果完成了一种可选择型低值电容标准器的整体结构设计,为其实际加工制作奠定了坚实的理论基础。
In electromagnetic metrology and electronic instrumentation,the stable capacitance standards including the selectable low-value capacitance standard( SLCS) are usually required for calibrating the instrumentations and meters to ensure its measurement accuracy. SLCS is a kind of standard equipment which can output different stable small capacitance values under the same system. This paper adopts the 3-D electrical field simulation software to research on the edge effect around the hole on the screen shutter which is one of the largest uncertainty sources for the SLCS. On basis of the simulation results,the overall mechanical structure for one kind of SLCS has been designed,which can lay a solid foundation for its actual realization.