亚纳秒级同轴电阻分压器研制及其不确定度评定

Development and Uncertainty Evaluation of Sub-nanosecond Coaxial Resistive Divider

为了保证纳秒脉冲电压测量用电容分压器的准确性,需在测量系统标定平台中布置标准电阻分压器作为基准分压器,通过测量结果比对的方式获得电容分压器的频率特性。因此,采用金属膜电阻研制了同轴电阻分压器作为电容分压器标定时的基准;研制了亚纳秒级上升沿的方波校准器,对此同轴电阻分压器进行了方波响应测试;并参照测量不确定度表示通用方法对其刻度因数不确定度和上升时间不确定度进行了评定。试验结果表明,所研制的电阻分压器可有效响应上升前沿约300 ps的方波,取95%置信区间时,其方波响应的刻度因数扩展不确定度为1.264%,上升时间的扩展不确定度为6.92%。

To ensure the measurement accuracy of capacitive voltage dividers for nanosecond high-voltage impulses, it is essential to arrange a standard resistive voltage divider in the calibration platform as a reference divider, and the frequency response characteristics of the capacitive voltage divider can be obtained by comparing the measurement results of the two dividers. In this paper, metal film resistors were adopted to design and develop a coaxial resistive voltage divider which was used as the reference in the calibration tests. A square wave calibrator with sub-nanosecond rise time was built and used to test the frequency response characteristics of the coaxial resistive voltage divider. The uncertainties of scale factor and rise time of the resistive divider were evaluated based on the guide to the expression of uncertainty in measurement. The test results indicate that the coaxial resistive divider has good response to the square wave with rise time of about 300 ps. The extended uncertainty of scale factor is 1.264% and the extended uncertainty of rise time is 6.92% when the confidence probability is 95%.