Table 1. Allowable counting errors according to the total activity in the sample received by the contracting laboratories. Radionuclide pCi 239,240p, lo error (%) <0.1 50 to 100 <<40 0.1 to 0.25 238,241 5, 241 An 1370, 0.25 to | <20 >1 <10 <2 50 to 100 2 to 5 <40 5 to 20 <20 > 20 <10 <0.1 0.1 to 0.25 0.25 to | 50 to 100 <40 <20 >] <10 <I 50 to 100 1 to 5 <30 5 to 8 <20 <1 50 to 100 1 to 5 <30 5 to 8 £20 >8 <10 <10 >8 905. (3) The third criterion required that the laboratories accurately determine the radionuclide concentrations of blind standards. Although all three of the criteria are important, perhaps this is the most significant because it includes accuracy of measurement as well as precision (reproducibility); any systematic errors in the measurement would appear. Responsibility for preparing,