摘要

在工业生产过程控制中，温度是一个重要的测量参数，而热电偶是工程上应用最广泛的温度传感器之一，他的主要特点就是测温范围宽，性能比较稳定，同时同时结构简单，动态响应好，更能够远传4-20mA电信号，便于自动控制和集中控制，在温度测量中占有重要地位。但由于热电偶的热电势与温度成非线性关系增加了显示与处理的复杂性；且随着工业发展、自动化的不断加强，对温度精度要求越来越高。在现代化的工业现场，常用热电偶测试高温，测试结果送至主控机。由于热电偶的热电势与温度呈非线性关系，所以必须对热电偶进行线性化处理以保持测试精度。该系统以单片机为控制核心，通过高精度模/数转换器对热电偶电动势进行采样、放大，并在单片机内采用一定算法实现对热电偶的线性化处理并通过液晶屏显示相应测量数据。本设计8路S型热电偶信号放大和冷端补偿电路，设计基于单片机的温度数据采集、传输和存储电路，并编写温度数据采集程序。

关键词：传感器热；电偶模/数转换器；液晶屏

Abstract

In the industrial production process control, the temperature is an important measurement parameters, and thermocouple is the most widely used temperature sensor, one of his main feature is the wide temperature range, the performance is relatively stable, while the structure is simple, dynamic Good response, more able to remote transmission 4-20mA electrical signal, easy to control and centralized control, in the temperature measurement occupies an important position. However, due to the thermocouple thermocouple and temperature into a non-linear relationship between the increase in display and processing complexity； and with industrial development, automation continues to strengthen, the temperature accuracy requirements are getting higher and higher. In the modern industrial field, commonly used thermocouple test high temperature, the test results sent to the main control machine. Since the thermoelectric power of the thermocouple has a non-linear relationship with the temperature, the thermocouple must be linearized to maintain the test accuracy. The system uses the single chip as the control core, through the high precision analog-to-digital converter to the thermocouple electromotive force sampling, amplification, and in the microcontroller using a certain algorithm to achieve the thermocouple linearization and display through the LCD display the corresponding measurement data. The design of 8-channel S-type thermocouple signal amplification and cold-side compensation circuit，Design based on the single-chip temperature data acquisition, transmission and storage circuits, and the preparation of temperature data acquisition procedures.

Key words: Sensor heat; galvanometer analog / digital converter; LCD screen