Abstract: The radon concentration in the environment will affect the decision threshold of aerosol monitors. Based on the radon and its daughters generation system of China Institute for Radiation Protection (CIRP), a set of stable circuits with adjustable internal radon concentration were established, and six domestic and overseas aerosol monitors were tested, in order to explore the effect of different environmental radon concentrations on the decision threshold of the aerosol monitors. Based on large number of experiments and data, it is recommended to select the correlation between the radon concentration and decision threshold of the aerosol monitor according to the monitoring mode of the aerosol monitor. When single measurement mode or fixed cumulative measurement mode is adopted, there is a linear relationship between its decision threshold and radon concentration. When mobile cumulative measurement mode is adopted, a power function relationship between its decision threshold and radon concentration is recommended.

Key words: radon concentration, continuous aerosol monitor, decision threshold