An easy-to-use combination four-terminal-pair/two-terminal-pair AC transformer bridge

Abstract

A new four-terminal-pair bridge, capable of achieving a relative standard uncertainty of 1 × 10-9, was constructed at the National Institute of Standards and Technology by converting a two-terminal-pair bridge. The conversion requires only the addition of components which are easily removed if two-terminal-pair measurements are to be made. The design and testing of this bridge is described. The new four-terminal-pair bridge requires fewer auxiliary balances than the present four-terminal-pair bridge employed at NIST, which makes it much easier to use. This new design can be used to compare capacitance, resistance, and inductance standards.