Aerosol particle spectrum and concentration measurement method based on light scattering response

Abstract

The invention discloses an aerosol particle spectrum and concentration measurement method based on light scattering response, and belongs to the field of aerosol on-line monitoring. The method comprises the following steps of: calculating the linear combination relationship between the scattered light intensity and the superficial area and volume of each particle, and determining the wavelength type of incident light adopted in actual measurement; according to the scattered light intensity of the single-wavelength incident light under the action of single particle, calculating a scattered light intensity and particle granularity conversion matrix; collecting the scattered light intensities of incident light with different wavelengths under the action of the to-be-detected aerosol, and acquiring aerosol granularity according to the conversion matrix; calculating a probability density function of the to-be-detected aerosol according to the aerosol granularity and the particle size of target measurement; and according to the probability density function, calculating a number concentration of the to-be-detected aerosol. The method is simple in principle, can rapidly and precisely acquire the aerosol particle spectrum and number, the surface area and the volume concentration, also an set a particle size measurement range according to needs, has a larger particle size measurement range, and has a wider application range.

Description

technical field [0001] The invention belongs to the field of aerosol online monitoring, and more specifically relates to an aerosol particle spectrum and concentration measurement method based on light scattering response. Background technique [0002] At present, smog frequently occurs in our country. The impact and monitoring of smog have attracted the attention of our people and the government. Various scientific researches on smog have become one of the urgent needs of our country. Studies have shown that the size (particle size) of atmospheric particles is an important parameter for their aerodynamic migration: fine particles with a particle size of less than 2.5 μm can enter the lungs through the filter system of human breathing and endanger health, and such particles usually form fog Haze core. The smaller the particle size, the larger the surface area, and the easier it is to be adhered to the alveoli. Among them, ultrafine particles with a particle size of less tha...

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Problems solved by technology

Among them, the sieving method is seriously affected by the shape of the particles, the measurement is rough, and it is impossible to analyze fine particles; the microscope method has a slow measurement speed and high cost, and the measurable area is small, so it is only suitable for laboratory use; the principle of the induction method is simple, but it is also It is only suitable for particle detection with a particle size greater than 1um and a small particle size distribution; the light scattering method is currently the most widely used aerosol measurement method, not only has a wide range of particle size measurement, but also has a fast measurement speed and good repeatability, but existing Most of the light scattering methods are based on statistical laws, and the atmospheric aerosols are approximated to lognormal distribution or Junge distribution, and then the distribution parameters are calculated according to the measurement results. There will be a certain deviation between the calculation results and the real distribution of aerosols, resulting in particle Inaccurate measurement of spectral distribution

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