Uncertainty evaluation and conformity evaluation of DC resistance tester

In order to investigate the reliability of verification results of DC resistance tester, the uncertainty of verification results was evaluated. According to JJF 1059.1-2012 “evaluation and expression of uncertainty in measurement”, a mathematical model is established to analyze the sources of uncertainty of measurement results and calculate the components of uncertainty. Taking 500mΩ point of DC resistance tester as a verification point, the standard uncertainty expressed by absolute value and relative value is 321μΩ and 0.064% respectively. Finally, based on the calculation of uncertainty, the conformity evaluation method and process of the tested instrument are given.