Multichannel high-precision temperature measurement system based on Pt100 platinum resistance

XV Li-zhen， BAO Min
（Faculty of Mechanical Engineering & Automation， Zhejiang Sci-Tech University， Hangzhou 310018， China）

Abstract： Aiming at the problems of low-precision measurement and repeating hardware circuit design in the Pt100 platinum resistance measurement of temperature，a design of multichannel high-precision temperature measurement system based on Pt100 platinum resistance has been introduced. The platinum resistance Pt100 was used as temperature sensor and the Atmega16L was chosen as the controlling core，the control of multichannel measurement has been realized by a group of analog switch CD4052. In order to realize high precision temperature measurement，the signal processing circuit of filtering，amplification，16-bit high-speed analog-to-digital converter ADS8320 was used. The method combining with look-up table and software compensation was used to make nonlinearity compensation. At the same time，on the part of the error source had been analyzed，then the system synthesis error was calculated. The results indicate that the measurement system has the advantages of high precision，good stability and strong scalability.
Key words： Pt100； high-precision； multi-channel temperature measurement system； Atmega16L