防静电工作区接地电阻的测量不确定度评定

Uncertainty Evaluation of Electrostatic Discharge Protected Area's Earth Resistance

接地电阻是评价防静电工作区防静电能力的重要指标,在依据三点法采用钳形接地电阻测量仪ETCR2000测量接地电阻的前提下,本文提出了接地电阻测量不确定度评定的通用方法。首先对接地电阻测量原理进行了分析,建立了测量结果的导出数学模型,并确定了两类测量不确定度来源;其次,进行了接地电阻的测量不确定度评定,重点处理了测量结果的相关性问题;最终,在接地电阻测量值的范围较宽的情况下,推导出了通用的不确定度计算公式,从不确定度理论上保证了防静电工作区接地电阻测量的准确性。

Earth resistance is an important index of anti-static ability for electrostatic discharge protected area. Adop- ting the Earth resistance tester ETCR2000 measuring the resistance by the three points method as a premise, the paper proposed universal uncertainty evaluation method for earth resistance＇ s measurement. First, the paper analyzed the measurement principle, established the deriving mathematical model of measurement results, and determined the two sources of measurement uncertainty; second, it evaluated measurement uncertainty of earth resistance, chiefly dealed with correlation of measurement result; Finally, the paper derived universal uncertainty formula, and ensured the measurement accuracy of EPA＇s earth resistance from uncertainty theoretically.