Metrological Properties of a Two-Output Transducer for Measuring Sum and Difference of Small Resistances

摘要

It presents an alternative realization of a circuit which supplies a resistance bridge, which has the form of a quadrilateral, equipped with two current sources and four electronic keys. The idea with alternately switched current sources allows to measure simultaneously small (up to 1 Omega) differences and sums of two changes in resistance taken from a pair of sensors plugged in the circuit. Problems relating to circuit realization and a way of signal processing are discussed. In the prototype transducer shielding and filtering RFI/EMI were used. The results of measurements conducted with the use of precision resistance decade boxes are presented.