摘 要：随着我国经济的发展，环境污染问题越来越迫切。SO2作为主要的大气污染物对环境造成严重的危害，因此建立完善的大气环境检测系统是非常必要的。

本设计选择3SF CiticeL电化学式SO2气体传感器作为敏感元件，并根据该传感器的特点，设计了合理的前置放大电路和后级放大电路；采用AT89C51单片机作为检测装置的核心处理器，完成信号采集、浓度计算、显示、报警等功能；配以显示电路、声光报警、键盘中断等接口电路，通过对单片机的编程实现各模块的功能。当SO2气体的浓度超过预先设定的报警阈值时，则产生声光报警信号。66638

通过实验证明，本系统功能齐全、运行稳定、界面友好、能很好的满足气体浓度的检测要求。

毕业论文关键词：二氧化硫检测，电化学，AT89C51，传感器

Abstract: With the development of our country economy, the problem of environmental pollution becomes more and more urgent.SO2 as the major air pollutants on the environment causing serious harm. Therefore, to establish a perfect atmospheric environment detection system is very necessary.

This design choice 3SF CiticeL electrochemical SO2 gas sensor as the sensing element, and according to the characteristics of the sensor, design the reasonable of the preamplifier circuit and amplifier circuit; AT89C51 microcontroller as the core processor of the detection device, signal acquisition, concentration calculation, display, alarm and other functions; together with the display circuit, sound and light alarm, such as keyboard interrupt interface circuit, through the microcontroller programming to achieve the function of each module. When the concentration of SO2 gas exceeds the threshold of the preset alarm, the sound and light alarm signal is generated.

The test results show that the system fully functional, stable operation, friendly interface,

good to meet the sulfur dioxide detecting requirements.

Keywords: sulfur dioxide detecting, electrochemical, AT89C51, sensor

目   录

1  绪 论 4

1.1  引言 4

1.2  二氧化硫浓度分析法 4

1.3  系统设计要求分析 5

2  3SF CiTiceL传感器 5

2.1  3SF CiTiceL传感器的检测原理 6

2.2  3SF CiTiceL传感器的技术说明 7

3  硬件电路的设计与实现 8

3.1  二氧化硫检测系统的工作原理 8

3.2  检测电路设计 9

3.2.1  3SF CiTiceL传感器的工作电路 9

3.2.2  LED显示电路 10

3.2.3  键盘电路 11

3.2.4  电路计算 11

3.3  单片机系统设计 12

3.3.1  单片机中央处理单元 12

3.3.2  时钟电路 14

3.3.3  复位电路 14

3.3.4  A/D转换器 15

4  检测系统软件设计与实现 17

4.1  控制软件设计 17

4.2  通信应用程序