“…The "external source area ratio" (ESAR) quench correction method was applied to measure 90 Sr/ 90 Y activities in aqueous samples with a wide range of quenching levels (Tsroya et al, 2009). This method was proved to be superior to all other quench correction methods (Tsroya et al, 2012) and is applicable also for determination of 90 Sr/ 90 Y in human urine (Tsroya et al, 2013). The goal of the present work was to check the applicability of direct Cherenkov counting when applying the ESAR quench correction method for the variety of milk products and try to find a common procedure which does not require quench calibration for each sort.…”