Abstract:

A high precision temperature measurement system based on low temperature drift precision voltage chip LT1083 low ripple of dc linear regulated power supply for power supply system and driven by constant current bridge three-wire system PT100 platinum resistance is achieved with analogue signals transformed into digital ones by the 16-bit high precision A/D converter AD7606 and sent to the STM32 microcontroller.The principles and the design of the constant-current bridge unit and signal conditioning unit,A/D conversion unit,and other function modules of the temperature measuring system are discussed and the linear error of the system is analyzed.The signals are converted into temperature by the STM32 algorithm.The experimental results show that the temperature measurement system offers stable and reliable performance with a temperature measuring difference ≤±0.01 ℃.

Key words: PT100;temperature measurement;STM32;constant current bridge