From Table2 can know that the 1:1 ratio measurement accuracy degrees of the bridge are respectively 5×10-8 and -2×10-7 when it works in different current situation. So, its accuracy degree is meets the measurement requirements. But, when use the double voltage method measuring, the minimum voltage of 10 nF capacitor are only 30 V, that time the bridge detection current is very low, the voltage of the inductive divider fluctuates relatively lager than other voltage. So, the A type uncertainty of multiple measurement of the bridge will increase, and which may affect the accuracy of the measurement result. Therefore, respectively select two groups 10 nF precision capacitor to use the exchange arm method to measure their 1:1 ratio, the data is shown in Tab.3 (T=20°C, RH=44%).