Effect of Excitation Voltage and Lead wire Resistance on Strain Measurement

The strain gauges are used to measure a strain in many practical applications. The uncertainty in measurement of strain is due to different factors such as excitation voltage, lead wire resistance and temperature. The aim of this project is to determine uncertainty in measurement for three bridge configurations for different parameters. The experimental sets up for three bridge configurations are developed for cantilever beam. The strain is calculated for different loads on cantilever beam from the pure bending theory using the hook's law formula and finite element analysis are validated with experimental measurements. The data has been analyzed for uncertainty in strain measurement for full bridge, half bridge and quarter bridge circuits. The result shows that full bridge configuration has minimum uncertainty value compare to other two bridges.