Abstract
In this paper a general method for γ-ray efficiency calibration is presented. The method takes into account the differences of densities and counting geometry between the real sample and the calibration sample. It is based on the γ-transmission method and gives the correction factor f as a function of Eγ, the density and counting geometry. Altough developed for soil samples, its underlying working philosophy is useful for any sample whose geometry can be adequately reproduced.