The Establishment of High DC Shunt Calibration System at KRISS and Comparison With NRC

The application of a binary step-up method has been investigated at the Korea Research Institute of Standards and Science (KRISS) for establishment of high dc standards based on the calibration system of high dc shunts up to a few thousand amperes in which the current dependence of the shunt resistance can be measured. A successive step-up method with a pair of high dc shunts was suggested to link the unknown high current to the values of low current level which are already known. The step-up approach was further modified with employing a current monitor to extract the information on the current dependence of the shunt and the source current changes during the step-up measurement. To validate the modified step-up technology, a comparison of high dc shunt resistance was carried out with National Research Council (NRC) in which both the KRISS and the NRC results agreed well within the standard deviation of the measurement on the order of about 0.01%.