| 摘要 |
PURPOSE:To measure the number of ultrafine particles accurately, by growing the ultrafine particles floating in air into large particles continuously and stably. CONSTITUTION:Aerosol from an aerosol inlet port 10 is guided to a low temperature vapor chamber 11, which is filled with the vapor of solvent 31 such as water or ethanol, through a valve 27 and a flowmeter 25. The aerosol is also guided to a high temperature vapor chamber 13, which is filled with the solvent by the similar way and is kept at a higher temperature than the chamber 11 by a heating means 14. Then, the aerosol including the vapor is blended in a blending chamber 15 in an adiabatic condition. The vapor is condensed and grown with the aerosol particles are cores. The vapor is grown into the size, at which light is dispersed. At this time, the change of the ratio of flow rate is adjusted by the operation of the valve 27. The change in temperature is adjusted by the operation of the heating means 14. Thus the degree of excessive saturation is controlled, and the cores are condensed under the optimum state all the time. The condensed and grown particles formed in this way are guided to a measuring mechanism 20 by a vacuum pump 29 and accurately counted by using an ultramicroscope 19 and the like. |
