10-kV High-Accuracy DC Voltage Divider

A high-accuracy voltage divider based on the Hamon/Rayleigh ratio principle has been made for the absolute measurement of the volt and also for building up the voltage scale to 10 kV. It is composed of 100 equal resistors of nominal value 100 kΩ and an adjustable 100-kΩ resistor with taps at 10 and 1 kΩ. By using appropriate connections, a total 10-MΩ divider with 1-kΩ output is constituted in which various voltage ratios up to 104 can be obtained. A guard circuit is provided to minimize the leakage currents. The calibration of the divider is simplified by using parallel or series-parallel connection of resistance elements so that all comparisons are made at a ratio of 1:1. For 10 kV only, two comparisons are required. The measurement of performance of the divider and the analysis of errors have been made. The most important factor affecting the voltage ratio is self heating, for which a correction is necessary. The total error would be less than 0.58 ppm.