[en] The invention deals with nuclear electronics and it can be used for correction of counting losses in spectrometers of nuclear radiations. The known device for correction of counting losses in the spectrometer is based on calculation of the ratio of real and operating time of. the analyzer in a period of time during which change of loading takes place within the limits set by the accuracy of correction. The purpose of the suggested invention is the increase of measuring accuracy of the alternated loading. It is attained by the fact that the generator outlet is connected with the inlet of the controlled divider of frequency, the controlled inlet of which is connected with the outlet of the register and the outlet of the controlled divider of frequency - with the inlet of the operating time counter