Fig. 3.
Gravimetric determinations of the mass of the CRM 112-A cleaned uranium metal used for the dissolution and the total solution mass. The mass of the U metal was obtained by two independent determinations using the AT-20 microbalance and the large-capacity Jupiter balance. The two results given, with a relative difference of 0.042 %, include air buoyancy corrections. The total mass of the master solution was obtained from the mass difference readings between the empty and filled bottle. This difference was multiplied by the air buoyancy correction shown. The balance was checked with added standardized weights (with the sum of the weight corrections δ for the added weights) at values bracketing each of the two readings. The numbers in parentheses represent the replication precision of the observed mass readings, given as tsm (product of Student’s t value for n = 3 with p = 0.95 and the standard deviation of the mean), and refer to the corresponding last digits of the quoted result.