Systems and methods for calculating gas densities within a fluid enclosure are disclosed. In an example embodiment, a system includes a temperature probe for measuring an enclosure temperature in a fluid enclosure filled at least in part with a fill gas, an atmospheric pressure sensor for measuring the atmospheric pressure outside the fluid enclosure, a gas sensor for measuring an enclosure pressure within the fluid enclosure, and a controller for calculating a fill gas density within the fluid enclosure based at least in part on the enclosure temperature, the atmospheric pressure, the enclosure pressure, and a gas coefficient of the fill gas.