The electrification of the dust of KCl monocrystals irradiated with &bgr; rays is influenced by 3 factors: absorption of electrons in the crystal, creation ofFcenters, and secondary emission. TheF‐center concentration in crystals irradiated with &bgr; rays for various irradiation times was measured spectrophotometrically. Based on theF‐center model and with the help of statistical calculations the relationship between theF‐center concentration in the crystal and the surface charge due toFcenters was found.