基于PT100铂热电阻的高精度温度实时监测系统

研究如何实现温度的高精度实时测试与监控至关重要。设计实现了一种基于PT100铂热电阻的四线制高精度温度测试与监控系统,采用OP484集成运放和基准源TL431设计恒流源为热电阻提供激励,热电阻产生的输出电压经信号调理放大电路进行放大,再送入AD变换器TLC2574进行模数转换,同时采用微控制器ATmega128通过RS232接口芯片MAX232接收PC上位机发送的控制命令,可以实现温度采集启动与停止、采集周期、精度等的命令控制。该系统消除了热电阻连接导线带来的测量误差,具有采集精度高、人机交互能力强等优点, 同时系统电路设计简单实用,性能稳定可靠。

High precision temperature measuring and monitoring system based on PT100

How to measure temperature realtime in high precision and monitor temperature has important significance. A four wire high precision temperature measuring and monitoring system using PT100 was designed. After exited by a constant current source using integrated components OP484 and TL431, the thermal resistor output a voltage signal. After amplification by a signal modulation and amplifying circuit, the signal was converted to digital signal using TLC2574 AD converter. Microcontroller ATmega128 accepted and interpretated commands from PC through an integrated RS232 interface circuit MAX232, as to control start and stop operation, sampling time, precision of the data acquisition and so on. The system eliminates the measuring error due to connecting wires of the thermal resistor, and has the characterstics of high precision and strong ability of human computer interaction. The circuit system design is simple, practical, stable and reliable.