关键词: 加湿浊度计, 散射吸湿增长因子, 吸湿性

Abstract:

In order to study the diurnal variations of aerosol hygroscopic properties in North China, a new humidified nephelometer system is designed with the advantage of high time resolution and high humidification efficiency. In this system, two water baths are used for the first time to control humidification process in turn, reducing the circulation cycle from two to three hours to about one hour. Besides the nephelometer lamp power is reduced from 75 W to 25 W, and a piece of heat mirror is set ahead of the lamp. After those modifications, the temperature rising inside the chamber decreases from 4.3 ºC to 2.3 ºC and humidification efficiency rises. The original RH sensor inside the chamber is inaccurate, so two Vaisala sensors are set at the inlet and outlet of the nephelometer to correct the RH inside the chamber. In the future, this humidified nephelometer system will be used in in situ measurement in North China to get the diurnal variation properties of aerosol light scattering enhancement factor.

Key words: humidified nephelometer, light scattering enhancement factor, hygroscopicity