MEASUREMENTS OF RADON FLUX AND THEIR VALIDATION

摘要

Two groups of methods for measuring radon flux (exhalation rate) from soils and building materials are reviewed: both direct and indirect (which measure concentrations of radon after its exhalation and then translating them into fluxes). The method of radon absorption by activated charcoal, as one of the most popular and reliable methods of measuring radon flux directly from the tested surfaces, is discussed. The mathematical model that describes the process of radon exhalation in a closed chamber is proposed. A special attention should be given to the interpretation of indirect measurements. The need to consider the difference between electret detectors, which are truly passive and do not perturb the system, and activated charcoal detectors, which are not ideal integrators, is emphasized, as well as the need to take into account the back diffusion by the material exhaling radon, when high concentrations of radon are achieved in the chamber. The experimental installation for calibration and metrological certification is suggested.