[en] Activity of elements determined by gamma ray spectrometry depends on the total number of counts in the full energy peak of the gamma line. The conventional method that considers the area under the peak is compared with and alternative technique that considers the number of counts at the maximum height of the central channel. The activity of low level radioactivity must have sufficient precision according to national and international norms. Graphical methods are employed for estimating the resolution and the maximum ordinate with low values of systematic errors. Both techniques were applied and compared for the analysis of the ⁴⁰K gamma line of 1460.8 keV in powdered milk samples with a H P Ge detector. (author)