Comparative impulse voltage measurements at the National Measurement Laboratory (NML), CSIRO, Australia, and the Institute for National Measurement Standards (INMS), NRC, Canada

This paper describes high voltage impulse measurements made under controlled conditions in two national measurement institutes to establish the best agreement that could be achieved in comparison measurements on small reference resistor dividers. These measurements at NML and INMS show that the peak voltage of a smooth impulse (measured as the peak reading of the record times the scale factor) can be measured in each laboratory with relative agreement within 4 mV/V. The uncertainty of this relative agreement, calculated from the standard deviation of the differences in each set of measurements, is 2 mV/V at a level of confidence of 95%. The relative agreement of front times was within 15 ms/s, with an uncertainty of 4 ms/s. The relative agreement of times to half-value was within 4 ms/s with an uncertainty of 2 ms/s.