Float adapted to track an interface between two liquids of differing density

摘要

A float adapted to track an interface between two liquids of differing density, includes a hollow buoyant body having an interior cavity adapted to retain liquid. At least one upper access opening is provided in the body, which is adapted to permit filling of the interior cavity with liquid. The interior cavity is capable of holding sufficient liquid to retard the buoyancy of the body. By filling the interior cavity with a liquid of a first density, the hollow buoyant body can be made to float at an interface with a lighter liquid of a second density.