Vol. 11, issue 01, article # 14

pdf Ogorodnikov B. I., Skitovich V. I., Khabarov V. I., Sharapov A. G. Parameters of autonomous isokinetic aerosol sampler in a wide range of wind velocities. // Atmospheric and oceanic optics. 1998. V. 11. No. 01. P. 70-73.
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Abstract:

The isokinetic aerosol sampler (IAS) is an autonomous device for monitoring of atmospheric pollutions. Air is pumped into the device due to the velocity head of wind and rarefaction created by a two-blade propeller (windwheel) rotated by the wind flow. Aerosols are deposited on a filter. The study of the influence of filter drag on the value m (the ratio of velocities of the inflowing air mass and the flow in the air tube) was performed in N.E. Zhukovskii Institute by use of the wind tunnel T-30. Resistance of filter medium [ΔP] was standard, from 2.3 to 48 Pa. The speed of air inflow was 2-25 m/s. Minimal air flow rates were recorded for media with [ΔP] = 48 Pa. In the range of wind velocity 5-15 m/s, the amount of air passed through the material was less by 20-25% as compared with the device without a filter, and by 12-14% as compared with the material FPP-15-1.6 for which [ΔP] = 16 Pa. Isokineticity (m = 1) is observed for the material FPP-15-1.6 at wind velocity V = 10-25 m/s. The value m decreases with the decrease of V. It reaches 0.8 for V = 5 m/s. For the material with [ΔP] = 48 Pa, we have m < 1 in the wind speed range 3-15 m/s; when V = 2.5-7.5 m/s, the value m coincides with those obtained for the filter medium with [ΔP] = 16 Pa. As for materials with [ΔP] < 10 Pa, m < 1 in the wind velocity range 5-25 m/s