多通道热电偶温度采集系统设计与实现

Design and implementation of multi-channel thermocouple temperature acquisition system

摘要:

随着温度测量技术迅速发展,近年来在多种工业测温环境中开始使用热电偶来测温,很大程度上提高了用户测量的便利性；针对国内热电偶采集系统多通道、高精度、快速测量的要求,实现了一种使用STM32控制的90通道高精度热电偶温度采集系统,系统采用STM32作为主控单元,使用分辨率为24位的A/D转换器AD7793,并使用K型热电偶传感器实时监测实验环境温度,并使用PT100温度传感器作为冷端补偿,进行热电偶信号的温度校准,最终实现在-20~280℃条件下的90通道热电偶温度监测；该系统支持RS485通信接口,并使用上位机软件实现温度的实时显示和记录；经验证,该系统能够实现90通道温度的精确采集,通过高低温箱进行温度测试该系统符合项目需求指标,且误差范围在±0.25,为工业领域温度测量和记录提供了便利、稳定的工程化解决方案。

Abstract:

With the rapid development of temperature measurement technology, thermocouples have been increasingly used in various industrial temperature measurement environments in recent years, greatly enhancing the convenience of users" measurements. To meet the requirements of multi-channel, high-precision, and rapid measurement of domestic thermocouple acquisition systems, a 90-channel high-precision thermocouple temperature acquisition system controlled by STM32 has been developed. The system uses STM32 as the main control unit, a 24-bit resolution A/D converter AD7793, and K-type thermocouple sensors to monitor the temperature of the experimental environment in real time. A PT100 temperature sensor is used for cold junction compensation to calibrate the thermocouple signal"s temperature. Ultimately, it achieves 90-channel thermocouple temperature monitoring under conditions ranging from -20 to 280°C. The system supports RS485 communication interfaces and uses upper computer software to display and record the temperature in real time. After verification, the system can accurately collect the temperature of 90 channels. Through temperature tests in high and low-temperature chambers, the system meets the project"s demand indicators, with an error range of ±0.25. It provides a convenient and stable engineering solution for temperature measurement and recording in the industrial field.