PROJECT TITLE :

Self-Compensating Networks for Four-Terminal-Pair Impedance Definition in Current Comparator Bridges

ABSTRACT:

The four-terminal-pair (4TP) definition of impedance standards allows reaching final accuracy in impedance metrology. Generally, the 4TP definition needs dedicated circuitry to be included within the bridge network and also the attainment of auxiliary bridge balances throughout the measurement. A careful choice of the network topology permits the bridge to be self-compensating: the 4TP definition is in massive half achieved by the behavior of the network itself without any adjustment. The extra circuitry required for impedance definition will so be simpler, the balancing procedure becomes easier, and a a lot of strong 4TP can be achieved. This paper analyzes a current comparator bridge network with a topology featuring self-compensation. A digitally assisted check bridge has been implemented; take a look at measurements on ac resistance comparison in the twenty five–100- vary at kilohertz frequencies are reported.