Standardization of 67Ga, 51Cr and 55Fe by live-timed anti-coincidence counting with extending dead time

In this work, the activity standardization of 51Cr, 55Fe and 67Ga by live-timed anti-coincidence counting with extending dead time is described. The difficulties of the method, the uncertainties of the results of the measurements and the comparison of these results with others measurement methods are discussed.