Improvements in the realization of the quantized Hall resistance standard at OFMET

A measurement system based on a cryogenic current comparator has been developed at the Swiss Federal Office of Metrology (OFMET) to maintain the electrical unit of resistance. Standard resistors in the range of 1 /spl Omega/ to 10 k/spl Omega/ can be measured against the quantized Hall resistance with an accuracy on the order of a few parts in 10/sup 9/. This recently completed system improves the measurement accuracy at OFMET in this range by 1 order of magnitude.<
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