粉じんによるレこザ光減衰特性

レこザ光による大気中浮遊粉じんの濃度測定法について

抄録

The present report deals with the quantitative analysis on the airborne dust concentration of coal and rock duct by the method of He-Ne Laser propagation loss.
the principal aim of study is to make it applicable for nractical use by applying the Transmission Method He-Ne Laser.
First of all, the relationship between the attenuation of He-Ne Laser (α) due to airborne dust and duct rnnrentration (W) was examined by the numerical computation of the equation:
α₀ [dB] =αR [dB] =0.4343ΣΣRγN (γ, ρ₀, R)·Qg (γ, m, λ)
α₀ [dB]: attenuation of He-Ne Laser by airborne dust, W [mg/m³]: dust concentration, R [km]: Laser propagation distanse ρ₀: specific gravity, m: refractiveindex, λ[cm]: wave length of Laser, N [number/m³]: size distriblltlon Qg [cm²]: cross section of Extinction and Scattering, γ[cm]: particle radius.
Then, the numerical values were compared with the experimental results obtained by the measurements of α, and W by cover glass method.
As a result, it has been confirmed that a is proportional to W (α=kW) for various kinds of nirhnrnp duct and that the theoretical values are coincide with the experimental values.
The proportional coefficient k is effected by specific gravity, refractive index, size distribution of dust, and wavp ipnath of Laser.
In consequence of the present study, we could have a hopeful view of application of the above method fnr the determination of an airborne dust concentration.