High-precision platinum resistor temperature measuring system and temperature measuring method based on same

Abstract

The invention relates to a high-precision platinum resistor temperature measuring system and a temperature measuring method based on the system. The high-precision platinum resistor temperature measuring system comprises an RC oscillator (101), a frequency measuring chip (102), a reference clock circuit (103), an SCM (104), a liquid crystal display (105) and a supervisory computer (106), wherein a platinum resistance sensor and a fixed capacitor form the RC oscillator (101) together by a two-wire connecting method; when the temperature changes, a resistance value of a platinum resistor is changed along with the temperature, the oscillation frequency of the oscillator is changed, thereby modulating the variation of the platinum resistor into a time-variant frequency signal; the frequency variation is measured by the frequency measuring chip; a measured value is transmitted to the supervisory computer; the calculation from frequency variation to temperature variation is finished in the supervisory computer by a high order polynomial equation, thereby realizing the high-precision temperature measurement by the platinum resistor. The invention has the characteristics of high temperature measuring precision, low realization cost and favorable stability.

Description

technical field [0001] The invention relates to a temperature measurement system, in particular to a high-precision platinum resistance temperature measurement system. Background technique [0002] Temperature is one of the seven basic physical quantities in the International System of Units. The standard platinum resistance thermometer has the characteristics of high precision, high sensitivity and high stability, so it is widely used in the temperature measurement of intelligent instruments. Most of the existing methods are to convert the resistance change into a voltage signal through a resistance bridge, and then send it to the A / D converter to complete the temperature acquisition after a series of filtering and amplification processing. This type of method needs to solve two problems: (1) Due to the influence of temperature on the resistance value of the platinum resistor and the amplifier, the system will produce a certain system error when the ambient temperature cha...

AI Technical Summary

Problems solved by technology

This type of method needs to solve two problems: (1) Due to the influence of temperature on the resistance value of the platinum resistor and the amplifier, the system will produce a certain system error when the ambient temperature changes

(2) With the improvement of measurement accuracy, the price of high-resolution A / D converters has increased significantly, resulting in high cost of measuring instruments is another problem faced

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