Investigative techniques for radon level characterization

Radon concentration measurements can be used for numerous applications in earth sciences and as an indicator of health risks in radioprotection. In this paper, two techniques for in situ radon level characterisation are presented: a proportional counter (active) and solid state nuclear track detectors (passive). A new development of the proportional counter has been performed. This electronic device measures radon concentrations in soil, ground water or the atmosphere on a continuous basis. Different parameters such as temperature and atmospheric pressure can also be measured during the radon detection process. Results are stored in an associated data processor. A special cell using a cellulose nitrate detector (LR115, Kodak France) has been developed for the passive technique. The response of these detectors, including the influence of the device's polyethylene membrane (used to wrap the cell to protect the detectors from humidity and thoron exposure) on diffusing radon toward the detection cell, has been modeled.