A station has been installed at the Rocky Flats Nuclear Safety Laboratory to volume-calibrate their storage tank farm housing 560 kg of enriched (93.2% 235U) uranium solution. The calibration (relating contained solution volume to height) of tanks used to store or process fissile materials is often complicated by the large surface area presented by thousands of borosilicate glass rings used for criticality prevention. Yet, an accurate and reliable measurement of this relation is important to good material accountability and possibly to nuclear safety. The latter purpose can be served by detecting accumulations of insoluable precipitates or the formation of critically unsafe voids in the bed of rings. With this station, calibrations are easily accomplished with an accuracy better than 1 liter at any point within a 500-liter tank. Additional benefits include increased safety through reduced potential for contamination release, improved efficiency since one operator replaces the previously required two, and the complete elimination of both solid and liquid contaminated waste generation.