Application of Digital Potentiometer in Measurement of Balance Bridge

To decrease the measuring error,the balance bridge is often used in the bridge measurement.The final output of the balance bridge is zero and its error is just determined by the precision of the potentiometer and the linear relation with the measured reference,having nothing to do with the power voltage.The process of zero adjusting is complex and time-consuming in traditional balance bridge measurement.The principle of the balance bridge and features of the digital potentiometer were analyzed.The balance bridge was composed of a sensor and the digital potentiometers used adjusting components.The output of the balance bridge is transmitted to A/D converter through the amplifier.The digital potentiometer is automatically adjusted according to the output of the balance bridge by the MCS-51 micro-controller.In this way,the digital balance bridge comes true and meets needs of the high speed and accuracy.