[en] The container is a thick-walled cylindrical vessel of stainless steel filled with lead which forms the radiation shielding. In the bottom part of the container is a recess with graded diameters into which is inserted a plug with the source carrier. The source is on a holder mounted in a casing adjusted for handling in a hot chamber. In the upper part of the container there is also a recess with a rotary drum also filled with lead, with an excentrically built-in collimator. The drum is driven with an electric motor and is remote controlled. For the needs of the sector calibration plant two types of such containers were designed for different gamma radiation sources for the development of a group standard. (M.D.)