A sensitive detection electronics for resistive sensor

Present work deals with the development of a low cost, appreciably accurate precision electronic circuit for resistive sensor where measurement of the incremental resistance with high degree of accuracy is essential. A linear and sensitive active bridge circuit requiring only few components for its hardware implementation has been proposed for measuring very small resistance change due to change in physical quantity or chemical analytes. Theory of the proposed active bridge circuit has been discussed and experimental results have been compared with conventional bridge circuit. Initial measurements are made with Pt-100 Strain gauge sensor but it can be extended to other resistive sensors of practical importance. Results show that the active bridge circuit is almost four times more sensitive than conventional full bridge circuit.