多通道智能热电偶测温模块的研制

Multiple-channel Smart Temperature Measuring Module Based on Thermocouple

火电厂的温度测量具有温度高且点数多的特点,目前普遍采用热电偶传感器来进行温度测量。文中介绍了一种应用于火电厂温度测量的多通道智能热电偶测温模块的具体研制方案。该测温模块具有3大优点:首先可同时测量16个通道的温度点,每个通道的温度点可配置8种不同类型的热电偶传感器;其次采用了带数字滤波功能的高精度模数转换器(AD),可以有效滤除工频干扰;最后通过外部标准电压源进行精度校准、冷端补偿与插值计算,提高了测温精度。

The number of temperature measuring points is lager and the temperature is high in thermal power plants. Thermo- couple sensors are widely used in thermal power plants for temperature measuring. This paper introduced a detail design of multi- pie-channel smart temperature measuring module based on tbermocouple in thermal power plants. The module has three advanta- ges ,first it can measure sixteen channels＇temperature points and every temperature point can be fixed with any of the eight thermo- couple sensors. Second it used high accuracy analog-to-digital converter（ ADC ）with digital filter that can reject power frequency in- terference. And it has high measuring accuracy of temperature by using high accuracy external reference calibration, cold junction compensation and interpolation algorithms.