Liquid to gas leak ratios with liquid nitrogen and liquid helium

To predict the leak rates of liquid helium and liquid nitrogen containers at operating conditions we need to know how small leaks (10-8 to 10-5 atm-cm3 air/s), measured at standard conditions, behave when flooded with these cryogens. Two small leaks were measured at ambient conditions (about 750 Torr and 295 K), at the normal boiling points of LN2 and LHe, and at elevated pressures above the liquids. The ratios of the leak rates of the liquids at ambient pressure to the gases at ambient pressure and room temperature are presented. The leak rate ratio of LN2 at elevated pressure was linear with pressure. The leak rate ratio of LHe at elevated pressure was also linear with pressure