A novel sensitivity enhancement technique employing wheatstone's bridge for strain and temperature measurement

Abstract

An improved sensitivity enhancement technique for strain and temperature measurement has been presented. In the present work, the conventional Wheatstone's bridge has been modified using active devices for enhancement of sensitivity by twelve times. It can also measure incremental resistance precisely and linearly. Experiments have been carried out for validation of the proposed circuit for both strain gauge and RTD and results showed that the maximum error was limited to within ± 1.5% for either case. The proposed circuit is very low cost and involves a few active components. The theory of the proposed circuit has been established and then validated with conventional half bridge circuit for both strain and temperature measurement. The experiments were conducted with strain gauge sensor for strain measurement and a Pt-100 RTD sensor for temperature measurement. The results obtained show that the output of the circuit is almost twelve times than the conventional half bridge circuit.