Resistance network for verifying the accuracy of resistance bridges

Abstract

A novel resistance network for verifying the accuracy of resistance bridges is described. The network of four resistors generates 35 four-terminal resistance values all interrelated by the formulae for series and parallel connections of resistors, and by appropriate choice of the resistors different resistance scales can be generated. Although many resistance bridges have internal calibration procedures, an independent check of the accuracy of such bridges when measuring actual resistances is often desirable. The network provides such a check and can be used to verify the accuracy of resistance bridges on a regular basis. It has been used to assess the accuracy of a cryogenic current comparator bridge and demonstrates an accuracy approaching 1 n/spl Omega///spl Omega/ at 100 /spl Omega/.