| 摘要 |
PURPOSE:To make it possible to accurately measure quantities of aerosol by particle size, by gradually reducing the number of jetting holes of the same diameter, and also by providing crystal oscillators on capturing plates of all the steps. CONSTITUTION:Jet plates 2a-2e of first-fifth sieving sections 1a-1e are provided with respectively prescribed number of nozzles 3a-3e, and although these nozzles are of the same diameter, number of the nozzles are lessened toward the bottom. And therefore, when a vacuum pump is connected to an exhausting gate 7 and suction is operated at a prescribed flow rate, flow velocity at the nozzle section becomes higher toward the bottom, and aerosol is sieved and captured on capturing plates 4a-4e in order of coarse particles size. All the capturing plates 4a-4b are equipped with their respective quartz oscillators 11a-11e immediately under the nozzles, and frequencies of the crystal oscillators are varied in proportion to quantities of captured particles. Therefore, it is possible to tell distribution of particle sizes by measuring variation of frequencies of the crystal oscillators of all the stages. |
