基于PT100热电阻的简易温度测量仪
摘 要：
本文首先简要介绍了铂电阻PT100的特性以及测温的方法，在此基础上阐述了基于PT100的温度测量系统设计。在本设计中，是以铂电阻PT100作为温度传感器，采用恒流测温的方法，通过单片机进行控制，用放大器、A/D转换器进行温度信号的采集。通过对电路的设计，减小了测量电路及PT100自身的误差，使温控精度在0℃～100℃范围内达到±0.1℃。
本文采用STC89C52RC单片机，TLC2543 A/D转换器，AD620放大器，铂电阻PT100及液晶系统，编写了相应的软件程序,使其实现温度及温度曲线的实时显示。该系统的特点是：使用简便；测量精确、稳定、可靠；测量范围大；使用对象广。 关键词：
PT100 单片机 温度测量 AD620 TL431
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Abstract
This article briefly describes the characteristics of PT100 platinum resistance and temperature measurement method, on the basis it describes the design of temperature measurement system based on PT100. In this design, it is use a PT100 platinum resistance as temperature sensor, in order to acquisition the temperature signal, it use of constant-current temperature measurement method and use single-chip control, Amplifier, A / D converter. It can still improve the perform used two-wire temperature circuit and reduce the measurement eror. The temperature precision is reached ±0.1℃ between 0℃～100℃. The system contains SCM(STC89C52), analog to digital convert department (TLC2543), AD620 amplifier, PT100 platinum, LCD12864, write the corresponding software program to achieve real-time temperature display. The system is simple , accurate , stable and wide range. Keywords:
PT100 MCU Temperature Measures AD620 TL431
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目录
前 言 .................................................................................................................................................. 4 第一章 方案设计与论证 .................................................................................................................... 6
1.1 传感器的选择 ........................................................................................................................ 6 1.2 方案论证 ................................................................................................................................ 7 1.3 系统的工作原理 .................................................................................................................... 8 1.4 系统框图 ................................................................................................................................ 9 第二章 硬件设计 ................................................................................................................................ 9
2.1 PT100传感器特性和测温原理 ............................................................................................. 9 2.2 硬件框图以及简要原理概述 ............................................................................................ 11 2.3 恒流源模块测温模块设计方案 ........................................................................................ 11 2.4 信号放大模块 ...................................................................................................................... 12 2.5 A/D转换模块 ....................................................................................................................... 15 2.6 单片机控制电路 .................................................................................................................. 18 2.7 显示模块 .............................................................................................................................. 19 第三章 软件设计 ............................................................................................................................ 19
3.1系统总流程的设计 ............................................................................................................... 19 3.2 主函数的设计 ...................................................................................................................... 20 3.3 温度转换流程图的设计 ...................................................................................................... 21 3.4 显示流程图 .......................................................................................................................... 21 3.5 按键流程的设计 .................................................................................................................. 22 第四章 数据处理与性能分析 ........................................................................................................ 23
4.1采集的数据及数据处理 ....................................................................................................... 23 4.2 性能测试分析 ...................................................................................................................... 23 第五章 结论与心得 ...................................................................................................................... 24
1 结论 ......................................................................................................................................... 24 2 心得 ......................................................................................................................................... 24 附录1 原理图 ............................................................................................................................ 25 附录2 元器件清单 .................................................................................................................... 26 附录3 程序清单 ........................................................................................................................ 27
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基于Pt100热电阻的简易温度测量系统资料
