A dual-balance high-resistance bridge in the range 1 T/spl Omega/ to 100 T/spl Omega/

The NIST dual-balance guarded active-arm bridge, using a third dc source and a second detector to balance the guard network, is described. Improvements to the NIST guarded active-arm bridge and the design and construction of improved high resistance standards have facilitated the extension of NIST calibration services to the 10 T/spl Omega/ and 100 T/spl Omega/ decades of resistance.