Apparatus for measuring small changes in liquid level in a container

摘要

A liquid level sensing apparatus for detecting leaks in storage tanks. A buoyancy member is at least partially immersed in the liquid, suspended from a pivoted, counterbalanced, parallelogram support arrangement with a radio frequency target sensing element for electrical readout of displacement. Two such apparatus are incorporated in a system with a provision for measuring a portion of the liquid of the tank in isolation from the remainder, in order to provide for temperature compensation.