Volume and density indicator system for liquids in tanks

Apparatus for determining the level and density of a liquid within a tank comprises a vertically disposed fixed tube positioned within the tank, a first float slidably mounted on said tube and adapted to float on the surface of the liquid within the tank, a second float slidably mounted on said tube and adapted to be immersed in said liquid to a depth which is inversely proportional to the density of said liquid, a pair of inner and outer concentric tubes disposed within said fixed tube for independent vertical movement with respect to each other, first complemental magnetic means carried by said first float and one of said concentric tubes adapted to be coupled through vertical movement of said one tube, second complemental magnetic means carried by said second float and the other of said concentric tubes adapted to be coupled through vertical movement of said other tube, a liquid level scale on said one tube and indicator means associated therewith to indicate a value thereon corresponding to the level of the liquid within the tank, and a density scale on said other tube and indicator means associated therewith to indicate a value thereon corresponding to the density of the liquid within the tank.