Design And Implementation Of Dust Mass Concentration Monitor Based On Adaptive Measurement

The dust mass concentration measurement is an important index of airquality. With the development of industrialization and the growth of urbanpopulation, the dust pollution becomes more and more serious, bringinggreat harm to human health. So realizing online monitor of dust massconcentration has important meaning to control air pollution and protecthuman health. However, the research level in this area at home is very lowand the technology of online monitor developed by ourselves is backward.Our domestic atmospheric environmental monitors are mostly passive andsemi-automatic with the shortcomings of small measuring range. So it is ofgreat meaning to develop the dust monitor with high automation and widemeasuring range.After analysis and comparison of several domestic and foreigncommonly used dust monitors, this research proposes an approach bytaking use of programmable amplifier which combined with the programjudgment method based on the thought of PID algorithm to control themeasurement process, expanding the measuring range and improving themeasuring accuracy. At the same time, this method obtains relativelysmooth data and realizes the adaptive measurement.On the basis of Mie scattering theory, this research analyzed thescattered light intensity distribution effected by particles, refractive indexand wavelength. It describes a good linear relationship between scatteredlight intensity of particles in a certain solid angle and mass concentration.This is the theoretical basis of designing the dust monitor in the research.This research completed the hardware design of the dust monitor, including preamplifier circuit, signal conditioning circuits, MCU controlmodule, serial communication circuit, display and keyboard input moduleand power circuit.This research also completed the software design, including the designof main program module, data acquisition and data processing module andcommunication module, etc. The software parts used the thought of PIDalgorithm to control the measurement process with the function ofhardware parts and realize adaptive measurement.A comparing measurement has been made between the8533seriesdust monitor and this monitor, and the results show that: this monitor canachieve good measurement effect. Its accuracy and precision are almostequal to foreign similar instruments, and the error is within8.5%. Thismonitor can measure the dust mass concentration from0to60mg/m².Finally, this paper gives summary and outlook on this research.