This paper gives the technical characteristics of the Italian Committee for Research and Development of Nuclear Energy and Alternative Energy (ENEA) radon chamber and the operational procedures developed for testing radon and daughters measuring equipment. Runs were carried out under different experimental conditions defined in terms of radon and daughter concentrations, equilibrium ratio (F-factor), and aerosol concentration and size distribution. Stable radon reference atmospheres with known equilibrium factors were obtained using standard aerosols.
Keywords: calibration; radon and daughters measuring equipment; radon chamber; radon reference atmospheres.