Current dependence measurement of 1 /spl Omega/ standard resistors using a cryogenic current source with linear output

We have developed a cryogenic current source with linear output up to 1 A, by combining a 1 mA current source with a cryogenic current comparator operating as a current amplifier. This source was used, along with a 1 V Josephson potentiometer, to determine the current dependence of two types of 1 /spl Omega/ resistors.