title: A double chamber system for producing constant radon concentration.
abstract: An experimental arrangement of a radon chamber with an intrinsic constancy of the relative radon concentration is described. The system consists of a reference chamber and an auxiliary storage chamber. The only active device is a timer-controlled pump or valve which feeds radon gas from the storage into the reference chamber. The switching pattern of the timer is extracted from model calculations and theoretically performs an exact compensation of the radon loss by radioactive decay. If the calculations are done in real time and online, every known external event influencing the radon concentration can be compensated. This paper presents a simple timer circuit and a computer code which generates the timer program. The influence of the air flow stability and the leakage of the chambers are discussed. It is planned to apply this theoretical approach to provide a constant radon gas concentration for an actual chamber.
authors.affiliation: GSF Forschungszentrum fuer Umwelt und Gesundheit, Neuherberg, Oberschleissheim, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Haider
authors.forename: J
authors.initials: J
authors.lastname: Peter
mesh_terms: D002138:Calibration; D008433:Mathematics; D008962:Models, Theoretical; D011886:Radon
chemical_list: D011886:Radon