A cryogenic current comparator bridge for resistance measurements at currents of up to 100 A

Abstract

The use of cryogenic current comparators at NPL has been limited so far to currents of 100 mA. A new current comparator with a maximum current capacity of 100 A has been developed and forms the basis of a resistance ratio bridge for low value resistors with a relative uncertainty of approximately 10/sup -7/ or better.