Toxic Gas Monitor System Design Based On Wireless Sensor Network

With the improvement of modern technology and development of industry, a variety of emissions produced in industry as well as toxic gases from interior dec- oration do harm to people lives.Although lots of equipments purifing air are in sh- ops,which can purify the toxic gases, they do not recognize whether there are waste gases or not in environment.Therefore, if the monitoring network of toxic gases is integrated in the purification equipment,detecting it qualitatively and keeping abreast of toxic and harmful gases in the environment of information in time, air purification equipment for the realization of intelligent control (such as: what purification method used? when is the purification equipment opened and closed?, etc.) is of great significance.What's more,understanding the changing tren -d of toxic gases in environment, for providing essential data for environmental monitoring in the industrial environment, the hospital environment and people's living environment.For detecting the toxic gases, there are many ways, such as analytical chemistry methods semiconductor gas-type detection methods, contact combustion-type detection methods, spectroscopy, electrochemical methods and so on.Electroc -chemical measurement is of fast response, which can measure the toxic gases on line and resist interference of non-measured gas strongly, by which the probes made are easy to be integrated with small.Therefore, the system studied by this paper adopts the electrochemical measurement .The gas detection equipments on market are de- veloped by a single gas detection, and they transmit data through the cable.If you need to test a variety of gases, the gas detection equipments integrated will be hu- ge.And then, if a large number of monitoring points required layout of the monito- ring environment, wired data transmission wiring is very troublesome and costly. So, This dissertation developed a toxic gas monitoring network integrated with air purification equipment, intelligence, small size and wireless.Specific researches are as follows:1.Gas sensor integrated designThe CO, formaldehyde, benzene and other gas sensors were integrated. The gas sensors were classified according to polarity and the sizes of output signals, and The same type of output signals processes integrated circuit design. 2.Wireless network communication system The integrated design about wireless communication nodes and gas sensors is to transmis sensor data and control commands sent by wireless node communicatio n. Controlling platform to establish computer centers to realize the monitoring poi- nts, sensor selection, and automatic processing of measured signals.3.System Calibration Testing LaboratoryDeveloped a measurement system of wireless monitoring network for charact- eristic testing of poisonous gas. Finished the demarcation of sensor characteristic, the comparison of accuracy, and communication distance test of system.Researched on the influence to the sensor characteristic of monitoring system from the ambient humidity.