CHARACTERIZATION OF A CONDENSATION-TYPE MONODISPERSE AEROSOL GENERATOR (MAGE)

A new condensation-type aerosol generator (designated MAGE) has been studied experimentally as a possible technique for the provision of test particles containing fluorescent cores for the calibration of aerosol analysis equipment. These studies have shown that careful selection of the operating conditions, particularly the gas flow rates through the system and reheater temperature, is required if aerosol of acceptable monodispersity are to be produced. It is especially important to avoid premature condensation of the aerosol-forming substance. In the case of di-2-ethyl hexyl sebacate (DEHS), the reheater temperature had to be increased from the recommended value (200-degrees-C) to at least 250-degrees-C to obtain good quality results. The size of the resulting droplets depended on the amount of DEHS vapour available for condensation. Thus, the largest droplets were formed when the vessel containing the liquid DEHS was maintained at high temperature (> 200-degrees-C) and all the gas flow passed through this vessel.