A System to Measure the Hygroscopicity of Aerosol Particles

Abstract

An aerosol conditioner (wetted wall reactor) was modified to mimic the conditions inside the human respiratory tract, i.e., relative humidity > 99% and 37°C. By combining the wetted wall reactory with tandem differential mobility analyzer, a system was developed to study the hygroscopic properties of aerosols in submicrometer range. This paper describes the system, and the results of system tests using three compounds of known composition, NaCl, (NH4)2SO4, and (NH4)HSO4, are presented.