Resistance scaling up to 1 M/spl Omega/ at PTB with a cryogenic current comparator

A cryogenic current comparator (CCC) of the Delahaye-type is used to scale the unit of resistance between 1 /spl Omega/ and 1 M/spl Omega/ in terms of R/sub K-90/. Measurements are demonstrated to check the accuracy and reproducibility of the system. Especially for the values above 10 k/spl Omega/ the uncertainty of the maintained standards could be reduced by more than one order of magnitude compared to conventional scaling methods.<>