High-accurate Resistance Measurement Method for Sensor Circuit

Abstract

An accurate resistance measuring circuit which is used complementary measurement and input compensation to make radiometric method as ideal as possible and reduce the influence that OAs' stray terms results based on radiometric method and dual-slope ADC circuit is proposed to solve the problem that we can't balance the precision and detection range of resistance measurement. The accuracy of method is almost related to the reference resistor. It can be calculated that the resistances near the reference resistance measurement error is less than 0.02% after using the complementary measurement under the high-precision OAs, and the measurement error is an order of magnitude smaller after using the input compensation. It is shows that the measurement error could be less than 1% with non-precision OAs. This circuit can be widely applied to sensor circuit.