热电偶毫伏信号发生器的设计与实现

摘要

A millivolt signal generator for thermocouples is designed. Using calculation advantage of LabVIEW, the computer can translate the required temperature into the thermocouples EMF and send it to MCU via USB or serial port. Controlled with the MCU, a 12-bit DAC could generate the voltage accordingly. The testing shows that this design can easily achieve millivolt signal generator for a variety of types of thermocouple, and improve the efficiency of the thermocouple instrument calibration, with the accuracy of ± 0. 1 ℃ for general occasions. It can adjust the range of temperature and supporting multiple independent output.%设计了一种热电偶毫伏信号发生器,利用上位机软件LabVIEW的计算优势,将所需的温差转化为相应的热电动势大小,并通过USB或串口发送到单片机,由单片机控制12位DAC转换电路输出相应的电压.测试表明,采用此种方法可以方便地实现多种类型的热电偶信号产生,精度可达±0.1℃,适用于一般的热电偶测量仪表的校准,并且可以根据需要对温度范围进行调节,同时支持多路独立输出,提高了校准效率.