High-precision multi-point temperature measurement system and temperature calibration method based on thermal resistor

Abstract

The invention belongs to the field of temperature measurement, and provides a high-precision multi-point temperature measurement system and a temperature calibration method based on a thermal resistor. The system comprises a chain type temperature sensor, an analog switch circuit, a signal acquisition unit, a single-chip microcomputer and a display unit. The chain type temperature sensor comprisesa plurality of thermal resistor temperature-sensitive elements, and the control end of the analog switch circuit is connected with the output end of the single-chip microcomputer; the signal acquisition unit is composed of an analog-digital conversion chip, the signal output ends of the thermal resistor temperature-sensitive elements are connected with the input end of the analog-digital conversion chip through the analog switch circuit; the detected voltage values of the thermal resistor temperature-sensitive elements are converted into resistance values R to be stored in the analog-to-digital conversion chip, and the single-chip microcomputer can obtain the acquired resistance value R of the thermal resistor through SPI communication; on the basis of the temperature calibration method obtained through analysis and calculation, data processing is achieved in the single-chip microcomputer, and an accurate temperature value is obtained. According to the system and the method, the temperature measurement precision in a low-temperature environment is effectively improved, and the system and the method can be widely applied to the field of environmental research.

Description

technical field [0001] The invention belongs to the field of temperature measurement, in particular to a thermal resistance-based high-precision multi-point temperature measurement system and a temperature calibration method. Background technique [0002] Temperature is one of the important measurement parameters in environmental research. The freezing phenomenon of rivers in alpine regions in winter is usually obtained by measuring the temperature of the river ice sheet section to obtain the evolution process of ice thickness. means. Therefore, improving the accuracy and stability of temperature sensor detection is an urgent requirement in the field of environmental measurement. [0003] As the current mainstream temperature sensor, DS18B20 has the advantages of small size, simple interface, and low cost. However, its accuracy is only 0.5°C, which is difficult to meet the needs of high-precision temperature detection. Although thermal resistance has the advantages of hig...

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Problems solved by technology

[0003] DS18B20, as the current mainstream temperature sensor, has the advantages of small size, simple interface, and low cost, but its accuracy is only 0.5°C, which is difficult to meet the needs of high-precision temperature detection

Although thermal resistance has the advantages of high temperature coefficient and high sensitivity, its resistance value has a nonlinear exponential relationship with temperature, so the use in low temperature environment must obtain a more accurate calibration equation through further research on the relationship between resistance and temperature. Accurate measurement of temperature

[0004] A method for predicting faults in fan gearbox subspace based on temperature data (CN 103743563 B) reports a technology that uses residuals as observations of a stochastic state space model and uses regression analysis to perform single-step predictions on temperature data. It is mainly used in the fault prediction of gearboxes, and has low requirements for temperature accuracy, and does not involve multi-point temperature measurement in low temperature environments

In addition, in the temperature measurement circuit of thermal resistance, analog switches are usually used to realize multi-point measurement of temperature, but the internal resistance of analog switches in low temperature environment will affect the final measurement accuracy

Therefore, it is necessary to invent a temperature measurement system that simultaneously considers the relationship between resistance and temperature and the internal resistance of the analog switch to solve the problem that it is difficult to achieve high-precision multi-point temperature measurement in a low temperature environment

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