SU1114148A1 - Method of determining spatial distribution of aerosol microstructure - Google Patents

Abstract

A METHOD FOR DETERMINING THE SPATIAL DISTRIBUTION OF THE MICROSTRUCTURE OF AEROSOL, V1sluchivayuschy illumination of the investigated aerosol by directed pulses of electromagnetic radiation at several frequencies V; no longer than 100, recording the time dependence of the signals reflected in the opposite direction, determining the spatial distribution of coes1 | Fnient backscattering (Vf, Zj) at a sequential setting of the frequency vf and certain distances Zj (j 1,2, ...) from the radiation source corresponding to the series; a number of selectable values of the distances, and the determination of the spatial distribution of the microstructure of the aerosol H (h jlj) over the minimum threshold P (Z j) min, where h is the radius of the particles, pMZjj | K (v) i, h) Y (Mj ) d., zjr,. I. , K (Yi, f) backscatter efficiency factor, characterized in that, in order to increase the accuracy of determining the spatial distribution of the aerosol microstructure, the Zo coordinate is determined from the minimum condition in the set of maxima .Zj) -p (Vi, Z)} - , H ,:, f. On. The distance 2 from the radiation source measures the particle size and determines the function fp (r, 2p of the aerosol size distribution density in ZpH), depending on the spatial distribution of the microstructure of the aerosol under the condition fMgj} -o (, (, z,). 4 00 I: II ьt} -Y (r.Zi)., where the empirical coefficients "/., 50-500, o (, 5. 5-10 - 10

Description

one

The invention relates to the field of instrumentation technology and can be used in the study of atmospheric physics, meteorology, and in the control of atmospheric pollution with industrial aerosols.

There is a known method of micropTpyKTypj i .i distribution, which consists in illuminating az12Rsrl with justified light emission and registering the intensity of the scattered light, according to which the particle sizes are determined.

The drawback of this method is the laboriousness of the measurement process in determining the spatial distribution of the aerosol microstructure of extended volumes, since it is necessary to take aerosol samples at many points in space.

The closest technical solution is a method based on illuminating the investigated aerosol in a set of light impulses II of electroscopic radiation at several frequencies V; radiation with a duration of no more than 100, recording the time dependence of the intensity of the signals reflected in the opposite direction, determining the spatial distribution of the backscattering coefficients p (v, jZj) for successively setting the frequency y, and certain distances ZJ from the radiation source corresponding to a series of selectable the distance values (j 1,2, ...) and determining the spatial distribution of the microstructure of the aerosol H (t, 1 j) microstructure according to the minimum of the restraint P (2j) mi.n, where h is the particle radius,

p (i) D: (i) Y (.)) l

I

(i) is the backscatter efficiency factor.

The disadvantage of this method is that it has low accuracy due to the fact that when determining the spatial distribution of the aerosol microstructure according to the backscattering coefficients, there are many size distribution functions that satisfy the measured backscattering coefficients. Therefore the spatial distribution of the microstructure

141482

the aerosol is determined with an accuracy of more than 100%,

The purpose of the invention is to improve the accuracy of determining the spatial distribution of the aerosol microstructure.

This goal is achieved by the fact that in the method of determining the spatial distribution of micro 10 structures illuminate the test aerosol with directional pulses of electromagnetic radiation at several frequencies) j with a duration of no more than 100 but register .- time dependence of the signals reflected in the reverse direction p (V;, Zj) when sequentially setting the frequency | and certain distances Zj from the radiation source, corresponding to a successive series of selectable distances (j 1,2, ...), determine the spatial distribution of the microstructure of the aerosol -f (, Tlj) at a minimum of p (Zj ) - min, "where I is the radaus of particles,

30, b (, Zj dr-ji (V ,, ij)

KCvijf) is the backscattering efficiency factor, a coordinate of 1.0 is determined from the minimum condition in the set

MaKCHrtyMOB (Sur (53p (Vi, Zj) - | i () i, Z,}, T at the distance ZQ from the radiation source measure particle sizes, determine the function (, 7 °) of the aerosol distribution density

sizes in z and specify the spatial distribution of the microstructure of the aerosol from the condition:

CFHzj) - ((r, 2j-Yo (r.Zo) t J ()

 iGjt () - V (Zj),

where the empirical coefficients are d 50-500; o / g 5-105-10-

An additional definition of M (ti, 1o) at the point o permits a substantial limitation of the range of possible solutions in the points adjacent to Z, and, accordingly, a reduction in the error

determine the microstructure of aerosol in them. Improving the accuracy of determining the microstructure of the aerosol at the points of the neighboring CTO in turn.

Claims (1)

METHOD FOR DETERMINING SPATIAL DISTRIBUTION OF AEROSOL MICROSTRUCTURE, including illumination of the aerosol under study by directed pulses of electromagnetic radiation at several frequencies V; with a duration of not more than 100 ns, recording the time dependence of the signals reflected in the opposite direction, determining the spatial distribution of the backscattering coefficients β (V, Zj) when sequentially setting the Frequency and certain distances Zj (j = 1,2, ...) from the source radiation, corresponding to a consecutive series of selectable distance values, and determination of the spatial distribution of the aerosol microstructure H (b, 1;) by the minimum of residuals P (Zj) = min, where, h is the radius of the particles, ¹ '' p ^r <* * .- poh. i ^j - backscattering efficiency factor, characterized in that, in order to improve the accuracy of determining the spatial distribution of the aerosol microstructure, the coordinate Z _o is determined from the condition of a minimum in the set of maxima Q NP [| ”M. g)) - MLL.Y *}. T ·. ^ · On. the distance Z _o from the radiation source measure the particle size and determine the function '(^ (Γ', ζζ) of the aerosol size distribution density in 2G _p and specify the spatial distribution of the aerosol microstructure from the condition jNO ·, 2-1.,) - ^, 7 , 1] ¼ ^^. J where empirical coefficients = = 50-500, o ( _z = 5-10 ' ⁵ - 10 “ ^3. SU„ ,, 1114148