Abstract: In a method and an apparatus for collecting components of a gaseous medium in a liquid, the gaseous medium is injected into a vessel containing a body of the liquid, below the surface of the liquid and directly into an homogenizer that subjects the bubbles of gaseous medium to a vigorous mechanical homogenizing action.

Abstract: An aerosol generating system for maintaining a constant concentration of aerosol in a chamber is disclosed. The system includes an aerosol generator in a closed chamber. A small fan in the chamber distributes the aerosol within the chamber. A particle analyzer connected to the chamber draws aerosol samples and analyses samples to monitor at least one characteristic property of the aerosol. Typically, these are particulate concentration and particulate size. The system includes a control responsive to signals from the analyzer representing changes in the monitored characteristic property to control operation of the aerosol generator. The control is such as to maintain the characteristic property substantially constant. The system may also be equipped with humidity and temperature control elements for maintaining these factors constant within the chamber.