Study On Atmospheric Turbidity Measurement Methods And The Design Of Its Device

In recent years, with the rapid development of industry, air pollution is getting more and more serious, and the air becomes turbidity sometimes, aerosol is the main reason why atmosphere getting turbid, In order to meet the high standard of living environment that people demand, environmental testing technology is increasingly development day and day, many countries have doing lots of research about the turbidity of aerosol, one of the most active research directions is optoelectronic monitoring technology. This thesis aiming at the mainstream test methods, after studying and researching on the basis of extensive investigation, single light source, double detectors, four light path was used in this thesis. Because the intensity will change as the light passed through the aerosol because of the absorption and scattering reason, according to periodic measure the 90°scattering and transmitting light, it can eliminate the inaccuracy because of light source aging and the difference of detector sensitivity, and it can reduce the system error.Scattering and transmission theory was deeply studied in this paper, besides that, the hardware circuit of this system was designed too. The instrument base on the microcontroller of MSP430.With the help of few external elements, it can achieve the real-time detection of turbidity. Optical signal was modulated by exerting pulse signal to laser tube and it would be amplified and filtered in the detected receiver, this system can effectively eliminate environmental interference signal on the measurement results. The operation of the detector was simplified, the structure is compact, and it has long-term high reliability.