One of the few analytical methods for low levels of uranium which can be adapted for continuous and automatic in-line analysis of Purex process solutions is the polarographic method. Polarographic monitors for uranium in aqueous wastes have been tested in plant and pilot plant operations during the past three years. From time to time the current-voltage waves obtained deviated so much from the classical "S" shaped curves as to render them virtually useless. Furthermore, the correlation of these periods of malfunction with process variables has met with little success. This report is concerned with the study of the effect of certain interferences and artifacts upon the appearance of the current-voltage wave and with the possible corrective measures to be considered in future designs. In some cases the phenomena involved are not understood, but an imperical solution can be offered. In other cases, even though the nature of the failure is known, little can be offered except the recognition of the type and probable duration of this failure.