STABLE TRACER AEROSOL DEPOSITION MEASUREMENTS IN A TEST CHAMBER

In order to provide data for evaluating the exposure of domestic build ing occupants to particulate pollutants from a variety of sources it i s necessary to to carry out aerosol deposition experiments in real hou se environments. To complement such studies in real houses, in which m any influences on aerosol deposition exist simultaneously, it is desir able to carry out aerosol deposition experiments in test chambers unde r controlled conditions. An aerosol test chamber, with the dimensions of a small room, is described. The chamber is fitted with air sampling ports so that aerosol deposition velocities can be inferred by monito ring tracer aerosol concentration decay. The use of neutron-activatabl e aerosol facilitates simultaneous surface sampling. This is not possi ble with conventional light-scattering aerosol detection techniques an d thus provides valuable information on mass transport limited deposit ion. Aerosol deposition experiments have been carried out, under turbu lent conditions using monodisperse neutron-activatable particles of fo ur sizes. Results are compared with the theory of Corner and Pendlebur y (1951, Proc. Phys. Soc. B64, 645-654). Surface sampling has been use d to obtain additional information from average aerosol deposition vel ocities. The potential of the test chamber as a means of assessing the influence of internal building surface character upon aerosol deposit ion velocity is illustrated.