Abstract: To meet the requirements of regulating equilibrium factor of radon and its progency, a generator of high concentration and mono-disperse aerosol based on the evaporation-condensation method utilizing diethylhexylsebacate (DEHS) droplets produced by an electronic cigarette generator and NaCl particles produced by an atomizer was developed to produce high concentration and mono-disperse aerosol. This developed aerosol generator was used in an 20 m³ radon chamber of the National Institute of Metrology. After one minute injection, the highest concentration of aerosol approached 2.26×10⁵ cm^-3 with an average particle size of 156.8 nm and a mono-disperse degree of 1.38. The equilibrium factor of radon and its progeny can approach to 0.65 with regulating of the developed generator.

Key words: high concentration aerosol, aerosol generator, radon progeny, equilibrium factor