Uncertainty Evaluation on Testing Results of Each Core Conductor Direct Current Resistance

According to GB/T 3048.4-2007 “Test Methods for Electrical Properties of Electric Cables and Wires-Part 4: Test of DC Resistance of Conductors”, the DC resistance value per kilometre at 20 ℃of a 2.5 mm2 single core copper wire was measured by using arm bridge method. And uncertainty components which might affect the measurement results were evaluated. The results show that the DC resistance value per kilometre at 20 ℃ of the single core copper wire was R20= (7.837±0.023) Ω·km-1, k95=1.96.