Aerodynamic size spectrometer

Abstract

The invention discloses an aerodynamic size spectrometer, which comprises a sample flow injection device, a particle beam collimation and acceleration nozzle, a shell flow device, a light beam focusing and reshaping device, a photoelectric detector, a signal detecting and processing module, and a micro-control and display module. The aerodynamic size spectrometer adopts flight time to measure aerodynamic diameter, and preceding stage particle size cutting and sampling is not needed, so that the particle loss is avoided, the sensitivity is high, and the accuracy of detection is high.

Description

technical field [0001] The invention relates to the field of air quality detection, in particular to an aerodynamic particle size spectrometer. Background technique [0002] In the atmosphere, pollutants are mostly attached to the surface of aerosol particles. The particle size of aerosols is generally 0.001-100 microns. It has been found that particles with an aerodynamic diameter above 50 microns cannot enter the human body due to gravity. Particles in the range of 10-50 microns can only enter the nasopharynx, particles in the range of 2.5-10 microns can usually enter the bronchi, and 80% of the particles below 2.5 microns can enter the alveoli of the human body. It has been reported that particles below 10 microns, especially those below 2.5 microns, are one of the main causes of the spread of respiratory diseases and lung diseases. In order to prevent the harm of PM10 particles to the human body, many countries at home and abroad have successively established PM10 stand...

AI Technical Summary

Problems solved by technology

The problems with this type of method are: firstly, since these two methods need to collect the particles of PM10 or PM2. The phenomenon of rebound and particle backflow makes the particle loss, which affects the test accuracy

Secondly, it is necessary to deposit a certain amount of particles before detection, so the detection speed is slow and real-time detection cannot be realized, and information cannot be obtained in time for some sudden events

[0004] In addition, in addition to the above two detection methods, people often use light-scattering devices to test particles, which generate scattered light after passing the particles through the laser beam, so that the particle size, concentration and other characteristics of the particles can be obtained on the photodetector. The existence of such devices The problem is that because it only relies on the light scattering intensity to measure the particle size, there is a large error in the measurement accuracy due to the influence of particle shape, scattering angle and other factors.

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