基于单直角电桥的交流电阻校准装置测量不确定度评定

本文基于单直角电桥原理，以数字式直角电桥源作为双路正交电压信号输出，搭建了交流电阻校准装置，利用单直角电桥的平衡方程，计算出待测交流电阻的阻值作为校准值。在频率1.591 55kHz、幅值有效值1V下，以标准电容100nF、交流电阻1kΩ为测试点，对交流电阻校准装置的测量不确定度进行了评定：建立了基于单直角电桥原理的被校交流电阻的数学模型，分析了测量不确定度的来源，并计算了交流电阻标准不确定度的各个分量。最后根据测量不确定度传播公式对其进行合成，计算得到合成标准不确定度，并通过扩展不确定度得到整个交流电阻校准装置的校准结果。

Evaluation of Measurement Uncertainty of AC Resistance Calibration #br# Device based on Single Quadrature Bridge

Based on the principle of single quadrature bridge,the digital quadrature bridge source is used as the output of the two-way quadrature voltage signal,for build the AC resistance calibration device.Via the equilibrium equation of the single quadrature bridge,the theoretical resistance of the pending AC resistance as a contract true value is calculated.In this paper,the measurement uncertainty of the AC resistance calibration device was evaluated based on a test point with a frequency of 1.591 55kHz,an amplitude effective value of 1V,a standard capacitor of 100nF and an AC resistance of 1kΩ.A mathematical model of the AC resistance based on the principle of single quadrature bridge is established,the source of measurement uncertainty is analyzed,and calculate the components of the standard uncertainty of the AC resistance.Finally,according to the measurement uncertainty propagation formula,the synthetic standard uncertainty is obtained,and the calibration result of the whole AC resistance calibration device is obtained by expanding the uncertainty.