Platinum resistance nonlinear correction temperature transmission circuit

Abstract

The invention relates to a non-linear platinum resistor correction temperature transmission circuit, which comprises a temperature-measuring bridge and a programmable gain amplifier PGA, the negative end of the power supply of the temperature-measuring bridge is connected with the signal earth through a common-mode matching resistor Rc, the output end of the temperature-measuring bridge is connected with the input end of the programmable gain amplifier PGA, a non-linear compensation resistor Rf is connected between the positive input end and output end of the programmable gain amplifier PGA, and thereby positive feedback is generated; and the temperature-measuring bridge is a single-arm bridge with a platinum resistor RT as one arm of the bridge. Since the non-linear platinum resistor correction temperature transmission circuit adopts the common-mode matching resistor and the non-linear compensation resistor, the resistance of the platinum resistor, which changes along with temperature, is converted into a voltage signal by the temperature-measuring bridge and the programmable gain amplifier, a linear hardware correction method is utilized, zero and full scale are digitally regulated, consequently, the defects of debugging errors and poor stability caused by a potentiometer or a resistor are prevented, and low-cost and high-precision temperature measurement is realized.

Description

technical field [0001] The invention relates to the field of detection technology and automatic control technology, in particular to a temperature transmission circuit. Background technique [0002] Temperature is an important physical quantity related to industrial and agricultural production, scientific research, environmental protection, meteorology, and even daily life. How to achieve accurate measurement is of great significance. Especially for temperature measuring instruments used in the process industry, it is required to have high temperature measurement accuracy, good reliability, and low cost. [0003] In the past, temperature transmitters were realized by using analog technology and single-chip microcomputer technology. Although the cost of temperature transmitters using analog technology is not high, they use potentiometers (or resistors) to adjust zero and full scale. , so it is difficult to achieve high debugging accuracy, and the potentiometer will drift wit...

AI Technical Summary

Problems solved by technology

[0014] The present invention aims at the above-mentioned problems such as large nonlinear error, low precision and poor stability existing in the temperature measurement of the existing temperature transmitter, and provides a platinum resistance with small nonlinear error, high measurement accuracy, good stability and low cost. Nonlinear Correction Temperature Transmitting Circuit

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