A Novel Fully Analog Null Instrument for Resistive Wheatstone Bridge With a Single Resistive Sensor

Abstract

When high-speed measurements are not necessary, the Wheatstone bridge-based null measurement instruments surpass the Wheatstone Bridge-based instruments using deflection technique, due to the fact that the null method has some intrinsic advantages over the deflection method. In this particle, a fully analog method has been introduced in order to implement a null measurement instrument for a resistive Wheatstone bridge with a single resistive sensor. In order to implement the proposed circuit, only two operational amplifiers and some passive elements have been used. The proposed method can be constructed and implemented by discrete components without any special limitation. Since the suggested scheme has linear output, the required computation in order to measure and display the measurand is reduced dramatically. Finally, in order to evaluate the performance and usefulness of the proposed method, it has been tested experimentally as well as by using computer aided design software.