一种PT100多通道测温系统设计及实现

Design of PT100 High-Precision Multi-Channel Temperature Measurement System Based on Domestic ARM

本文阐述了一种基于国产ARM芯片方案的三线制PT100高精度多通道测温系统的设计与实现。该系统采用国产ARM处理器和24位的高精度delta-sigma A/D转换器,使用恒压源与精密电阻对各通道PT100进行分压,再通过差分放大电路放大后进行采样,实现多路温度的准确测量。并且通过硬件电路设计与软件数据处理算法设计,有效地解决了接线电阻与自热效应对测温精度的影响。通过实物测试结果显示,该系统表现出性能稳定、体积小巧的特点,其测量精度可达0.5 ℃。

This article elaborates on the design and implementation of a high-precision multi-channel temperature measurement system for a three wire PTi00 based on a domestic ARM chip scheme.The system adopts a domestically produced ARM processor and a 24 bit high-precision delta-sigma A/D converter.It uses a constant voltage source and precision resistors to divide the voltage of each channel PTioo,and then amplifies it through a differential amplification circuit for sampling,achieving accurate measurement of multi-channel temperature.And through hardware circuit design and software data processing algorithm design,the influence of wiring resistance and self heating effect on temperature measurement accuracy has been effectively solved.The physical test results show that the system exhibits stable performance and compact size,with a measurement accuracy of up to 0.5℃.