Two-source Bridges as a New Kind of Measuring Systems

Abstract

The paper discusses the basic relationships and the state of research on a new type of bridge measurement systems with two outputs from both diagonals of a four-arm bridge. Their measuring circuits contain either two current sources or two voltage sources respectively unconventionally connected to opposite branches of these circuits. With direct current (DC), these bridges, after balancing the outputs of each of the diagonals, will enable measurements of two resistances (or two conductances) of their arms. As deflection bridges - they measure simultaneously increments of these resistances from balanced states in diagonals. The formulas for the voltages of both outputs of the systems and the balance conditions for each of them are given. As an example of application, the simultaneous measurement of stress and temperature increase with a differential two-element strain gauge was considered. The current state of theoretical work and the results of several experimental constructions of measuring instruments with a two-current bridge are briefly characterized.