Temperature measuring method and circuit adopting reference voltage compensation technology

Abstract

The invention discloses a temperature measuring method and circuit adopting the reference voltage compensation technology. The method is characterized in that a reference voltage source supplies power for a platinum resistor temperature measuring bridge while the temperature of the reference voltage source is measured through a digital temperature measuring sensor attached to the surface of the reference voltage source, and the temperature is transmitted to a FPGA chip; the platinum resistor temperature measuring bridge converts the measured temperature into voltage change, and the voltage change sequentially passes a filter circuit, an operation amplifier and an A / D conversion module and is input into the FPGA chip; the FPGA chip performs the error compensation and calculation of the measured temperature according to the temperature error calibration model of the reference voltage source and the nonlinear calibration model of a platinum resistor so as to output the digital quantity of the measured temperature. The method has the advantages that error compensation is performed on the output value of reference voltage, the reference voltage is kept accurate as much as possible during the calculation, and temperature measuring precision is increased to a large degree.

Description

technical field [0001] The invention relates to the technical field of temperature measurement, in particular to a temperature measurement method and a temperature measurement circuit using a reference voltage compensation technology. Background technique [0002] Platinum resistance thermometers occupy an important position in the field of temperature measurement due to their advantages such as wide temperature measurement range, high precision, good stability, high reproducibility of indication value and oxidation resistance. In order to reduce the influence of lead wire resistance on the temperature measurement accuracy of platinum resistance thermometers, a bridge circuit design is generally used. The principle is: use a reference voltage source to provide a voltage excitation for the bridge circuit, and the bridge circuit converts the reference voltage into a measurement voltage that changes with the resistance of the platinum resistance, and obtains the measured value ...

AI Technical Summary

Problems solved by technology

Among them, the voltage value output by the reference voltage source will drift with the change of external temperature. This temperature error is more prominent in high-precision temperature measurement occasions, which greatly affects the temperature measurement accuracy.

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