Relative uncertainties in the preparation of analytical solutions
A nalytical error As guidance to minimise errors in the preparation of analytical solutions, Table 1, giving estimations of the relative uncertainty, is to be consulted. In order to avoid either the use of extremely low amounts or an unnecessarily large expenditure of solvents, a dilution series will often have to be prescribed for the preparation of dilute solutions used particularly for spectrophotometry measurement. In this context not all combinations of (usually 2 or 3) dilution steps will contribute equally to the random error of the dilution procedure. If critical for the purpose, the optimal dilution is prescribed in consideration of the relative errors (capacity tolerance divided by nominal volume) associated with the various sizes of volumetric pipettes and volumetric flasks commonly used for these operations (taking the usual formula: square root of the sum of the squares of individual relative errors, to estimate the relative dilution error). Tables