Frequency dependence of some 100 /spl Omega/ resistors measured with a CCC-based AC resistance bridge

The paper describes frequency dependence of some 100 /spl Omega/ standard resistors in the frequency range from 0.1 Hz to 1 Hz. The measurements are carried out with an automated ac bridge based on the cryogenic current comparator (CCC) and a dc SQUID null detector. A GaAs quantum-Hall resistance cooled down to 1.4 K-1.8 K was used as a reference. The plateau i=2 was obtained at 7.5 T. Some resistors such as a N.B.S. type 100 /spl Omega/ (L&N) reveal a strong frequency dependence below 1 Hz while the frequency dependence of the Wilkins type 100 /spl Omega/ (Tinsley) is barely visible.<>