FIELD: environmental radioactivity monitoring. SUBSTANCE: in correspondence with procedure measuring number of negative ions of various mobility cylindrical ionization detector is filled with air and electric field intensity sufficient for detachment of electron from negative ion and for gas ionization by electron shock is formed close to filament charged positively. Mobility of negative ion is determined by distance from input of ion into detector to region of its registration on filament. Device for realization of procedure includes cylindrical ionization detector, blower, electrostatic filter, source of filter disabling voltage, high-voltage source recording electric pulses of electron circuit. EFFECT: separate recording of negative ions of different mobility. 4 cl, 1 dwg
