Study of the performance and time response of the RadonEye Plus2 continuous radon monitor
Résumé
The availability of afordable continuous radon monitors opens new opportunities for studying the dynamics of indoor radon and for more precise estimates of the exposure based on the actual occupancy of homes and workplaces.
These new applications require tests of the monitors characteristics, including their response time. A study of a promising electronic radon monitor with high sensitivity, the RadonEye Plus2, was conducted. By exposure of 36 RadonEye monitors it was found that they have excellent linearity up to 3500 Bq/m3. A slight deviation from linearity within 12% was observed in the range 3500{7000 Bq/m3. The reproducibility of the monitors was within 7%, estimated in the range of linearity. A dedicated procedure for studying the time response was developed based on exposure to rectangular activity concentration pulses (spikes). It was applied to the RadonEye and three other commercial monitors. The determined characteristic response times of the RadonEye monitor are about 40 minutes for reaching 50% of the plateau of a rectangular pulse and 90 minutes for reaching 90%. They are somewhat higher than the corresponding response times of the AlphaE monitor, which are 20 and 60 minutes respectively.
The response times of the RAD7 monitor in snif mode are about 3 minutes for reaching 50% of the plateau and 10 minutes for reaching 90%. The AlphaGUARD monitor in low-through mode has the fastest response { reaches 95% of the plateau in less than 2 minutes. The monitor Alpha-GUARD PQ2000 Pro Rn/Tn is therefore recommended for follow-up of the activity concentration in time response studies of other monitors. Overall, the RadonEye's response is suffciently fast to follow the diurnal variations even in buildings with active ventilation. The presented methodology
can be applied to other monitors for continuous radon measurements. It is demonstrated that it can be expanded to obtain the response function of a monitor and to model its response to variable concentrations.
Overall, the RadonEye’s response is sufficiently fast to follow radon variations even in buildings with active ventilation. This sensitive monitor is suitable for homes and workplaces and can be helpful in the installation and investigation of radon mitigation systems and in studies of the indoor radon dynamics.
