Measurement of oxygen pressure increase in magnetic field

Water surface profiles were observed in nitrogen and oxygen atmospheres in gradient magnetic fields, ranging from 0.6 T to 8 T. In the case of a nitrogen atmosphere, the water surface was suppressed in the region exposed to high fields only by the diamagnetism of water ("Moses effect"). In the case of oxygen, however the water surface was further suppressed because of the increased oxygen pressure in the field. The change in oxygen pressure, estimated experimentally from the difference in the water level, agreed quite well with the theoretical value, hence suggesting that the observation of the surface profile of a liquid can provide a potential method for obtaining the change in the gas pressure in a strong magnetic field.