A fully automated radon exposure chamber

Abstract

A fully automated radon exposure chamber is described. The chamber is made of stainless steel and has a volume of 1.46 m3. The chamber allows 222Rn, 220Rn or both to be injected from the bottom pipe-lines into the chamber in a 100% flow-through mode, 100% recirculate mode or flow-through/recirculate mode. Either atmospheric aerosol or monodisperse aerosol from aerosol generator can be injected into the chamber. The radon concentration; radon daughter concentration; unattached fraction of radon daughters; aerosol size distribution and activity size distribution of radon daughters in aerosols are continuously monitored by computers and feedback signals are used to maintain the specified condition. Though the chamber may be small when compared to walk-in type exposure room, it has the advantage of fast response to changes in the chamber condition and yet is large enough to preclude perturbations due to sampling or other activities. © 1994.