【正文】 湖州師范學(xué)院求真學(xué)院教務(wù)部印制 氣 敏 傳 感 檢 測 報 警 系 統(tǒng) 研 究 綜 述 摘要 ：當該氣體含量過高，將直接對我們生命、財產(chǎn)造成不可預(yù)估的威脅。 本文分析 ADC0809體系結(jié)構(gòu)，描述液晶 TR1602 的工作原理。 關(guān)鍵詞 ： ADC0809， MQ_7傳感器，報警， 51 系列單片機， TR1602 Abstract： When the air39。s air protecting awareness and governments carry out their environment protecting measure,finally making more and more countries。 The task is designed according to the following conditions:as the develop of industry and society, air pollution like exhaust gas,thus caused is more and more 39。 本系統(tǒng)為一個報警裝置。 本課題是針對工業(yè)和社會的進步，工廠排放的廢氣、煙道氧、汽車排放廢氣、內(nèi)燃機等的排放對空氣造成的污染日益嚴重，再加上國家環(huán)保政策的貫徹落實以及人們環(huán)保意識的不斷增強，使得世界各國都紛紛致力于防止空氣污染的產(chǎn)生的思想設(shè)計的。（ 1～ 2分） C、軟件源代碼書寫具有一定的格式。（ 5～ 7分） C、軟件能在少量的平臺上移植。（ 7～9分） C、軟件源代碼能讓人讀懂但較費勁。（ 4～ 6分） C、軟件文檔有較多的地方意思含糊不清。（ 0分） （ 2）軟件文檔書寫規(guī)范程度（計10分） A、軟件文檔書寫規(guī)范。（ 1～ 5分） 2 軟件文檔（計 28分） （ 1）軟件文檔是否齊全（計 10分） A、軟件文檔齊全。（ 1～ 3分） （ 2）軟件正確性（計 20 分） A、軟件調(diào)試完全正確。（ 0分） 軟件功能（計 45分） （ 1）軟件功能是否完備（計 25分） A、軟件功能完備。（ 0分） （ 2）軟件界面友好程度（計 3分） A、軟件界面友好。 畢業(yè)設(shè)計 (論文 )軟件驗收評分表 畢業(yè)設(shè)計題目： 氣敏傳感檢測報警系統(tǒng) 下屬學(xué)院： 求真學(xué)院 專業(yè)： 信息工程 作者姓名： 潘泓旭 班級： 040832 學(xué)號： 13 指導(dǎo)老師姓名： 陳建清 序號 評分標準及其內(nèi)容 評分 序號 評分標準及其內(nèi)容 評分 1 軟件界面（計 6分） （ 1）軟件界面美觀程度（計 3分） A、軟 件界面美觀。 要求重視實驗研究，多做實驗，發(fā)現(xiàn)問題，研究并解決問題，提高設(shè)計質(zhì)量。 Preheat time No less than 48 hours Delecting range: 20ppm2020ppm carbon monoxide D． Structure and configuration,basic measuring circuit Structure and configuration of MQ7 gas sensor is shown as Fig. 1(Configuration A or B),sensor posed by micro AL2O3 ceramic tube,Tin Dioxide(SnO2) sensitive layer,measuring electrode and heater are fixed into a crust made by plastic and stainless steel .The heater provides necessary work conditions for work of sensitive enveloped MQ7 have 6 pin,4 of them are used to fetch signals,and other 2 are used for providing heating current. Standard circuit: As shown in Fig 2, standard measuring circuit of MQ7 sensitive ponents consists of 2 parts. one is heating circuit having time control function (the high voltage and the low voltage work circularly ). The second is the signal output circuit, it can accurately respond changes of surface resistance of the sensor. Electric parameter measurement circuit is shown as E. Sensitivity characteristic curve sensitivity characteristics of the MQ7 is shows the typical sensitivity characteristics of the MQ7 for several gases. in their: Temp: 20℃、 Humidity: 65%、 O2 concentration 21% RL=10kΩ Ro: sensor resistance at 100ppm CO in the clean air. Rs: sensor resistance at various concentrations of gases. is shows the typical dependence of the MQ7 on temperature and humidity. Ro: sensor resistance at 100ppm CO in air at 33%RH and 20degree. Rs: sensor resistance at 100ppm CO at different temperatures and humidities. OPERATION PRINCIPLE . The surface resistance of the sensor Rs is obtained through effected voltage signal output of the load resistance RL which serieswound. The relationship between them is described: Rs\RL = (VcVRL) / VRL Fig. 5 shows alterable situation of RL signal output measured by using Fig. 2 circuit output signal when the sensor is shifted from clean air to carbon monoxide (CO) , output signal measurement is made within one or two plete heating period ( minute from high voltage to low voltage ). 2 with stability, So, it has Sensitive layer of MQ7 gas sensitive ponents is made of SnO excellent long term stability. Its service life can reach 5 years under using condition. SENSITVITY ADJUSTMENT Resistance value of MQ7 is difference to various kinds and various concentration gases. So, When using this ponents, sensitivity adjustment is very necessary. we remend that you calibrate the detector for 200ppm CO in air and use value of Load resistance . When accurately measuring, the proper alarm point for the gas detector should be determined after considering the temperature and humidity influence. The sensitivity adjusting program: a. Connect the sensor to the application circuit. b. Turn on the power, keep preheating through electricity over 48 hours. c. Adjust the another load resistance RL until you get a signal value which is respond to a CO concentration at the end point of 60 seconds . AT89C51 The AT89C51 provides the following standard features: 4K bytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16bit timer/counters, a five vector twolevel interrupt architecture, a full duplex serial port, onchip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters,serial port and interrupt system to continue functioning. The Power Down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset. Pin Description V CC： Supply voltage. GND： round. Port 0： Port 0 is an 8bit open drain bidirectional I/O port. As an output port each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as highimpedance inputs. Port 0 may also be configured to be the multiplexed loworder address/data bus during accesses to external program and data memory. In this mode P0 has internal pullups. Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during program verification. External pullups are required during program verification. Port 1： Port 1 is an 8bit bidirectional I/O port with internal Port 1 output buffers can sink/source fou