The Heinrichs BA Series displacer level gauge for liquids from KOBOLD Instruments operates on the Archimedes principle. The level gauge’s displacer tube rests inside the tank and is connected to the measuring unit via a spring. As liquid level increases, the buoyant forces of the liquid act on the displacer tube to reduce spring tension, allowing the spring to expand. The spring connects to a magnetic actuator, and the motion of the actuator is picked up by a magnetically linked indicator to yield the tank level measurement. The BA Series displacer level gauge is calibrated at the factory for the user's specified liquid density. Special designs with higher pressure or temperature ratings, as well as those made of exotic materials, are always available on request.