1、 本科毕业论文 (设计 ) 外 文 文 献 翻 译 译文题目： Design of detection of combustible gas and alarm system 学生姓名： 专 业： 指导教师： 2013 年 2 月 第 1 页 原文 ： Design of Combustible Gas Detection system using Wireless Transmission Technology Shijiazhuang Universities of Economics, Hebei, China Keywords:TGS813, AT89S52, DS18B20, nR
2、F905, TC35i Abstract.The detection device of combustible gas are designed in the presented work,using wireless transceiver and GSM network.The system realize the wireless transmission of the gas concentration,and also can send alarm information to users mobile when an exception occurs. The system co
3、nsists of two parts: a master and slave. The function of the slave is to collect data, process data and transffer the data to the master.The taskof the master is to receive data and display it by LED. The signal acquisition is completed by sensor TGS813 and A/D converter TLC2543. The wireless transm
4、ission is achieved through wireless transceiver nRF905. Since the accuracy of the sensor is affected by the environment,using DS18B20 to achieve temperature compensation. And with wireless communication module TC35i and GSM network platform, we can send the alarm information to users mobile promptly
5、. Introduction Gas detection is widely used in petroleum, chemical, metallurgy, family, shopping malls, gas stations and other places. Currently, how to monitor the hazardous gas fast and accurately are the important issues. Although the gas detection technology is relatively mature, but most produc
6、ts has many shortcomings, such as single function, operating complex, bulky, expensive and low sensitivity. Wireless communication technology applied to the gas monitoring field, can resolve the problem of remote monitoring in special environment, such as high temperature, low temperature, toxic gas
7、.and unable to wiring . In the presented work, the combustible gas detectoris fully functional (with wireless transceiver), simple, small size, low cost, and has high sensitivity. The equipment can greatly improve the systems detection capability and accuracy with temperature compensation algorithm,
8、 and also can send alarm information to the users mobile phone promptly through the GSM network. System design The system consists of two parts as shown in Figure 1. Fig. 1 Overall system block diagram 第 2 页 The slave part mainly complete data collection and wireless transmission. The master part ma
9、inly complete receiving data, displaying and sending alarm message. The signal of gas concentration is collected by combustible gas sensor which generates a weak electrical signal. The signal can be amplified and stabilized by conditioning circuit. And then A/D circuit converts the analog signal to
10、digital signal which microcontroller can process. In order to improve the measurement accuracy, and reduce the impact of temperature, design a temperature compensation circuit to collect tempreture data. AT89S52 process the collected data and send data to the master by wireless transceiver. The mast
11、er receives the data and displays it by LED. And if the gas concentration being abnormal,the system will drive speaker for an alarm signal and use TC35i module to send alarm information to users mobile. Hardware design Signal acquisition and conditioning circuit. Figure 2 shows data acquisition circ
12、uit. TGS813 is a Gas sensing resistive sensor. The conductivity of TGS813 is influenced by the concentration of combustible gases in air, the greater the concentration, the higher conductivity. In system R0, R9, R10 and RS (in TGS813) form a bridge circuit to convert resistance to voltage signal. Op
13、erational amplifier A connected as a voltage follower with resistors R7 and regulator D1 make up the voltage regulator circuit to supply power for the bridge. In order to the voltage adapt to the A/D converter, the voltage is amplified by opamp B, and the magnification can be adjusted through resistor R11. Fig. 2 Gas concentration signal acquisition circuit Fig. 3 Temperature compensation circuit
