Level transmitters measure hydrostatic pressure using a simple air purge connection to the tank. An integral specialized airflow regulator ensures linear response throughout the entire operating range. These level transmitters are also available with integral containment barrier against release of liquids or vapors.
A downpipe is the simplest type of liquid level sensor, often referred to as a “bubbler”. This is merely a length of open ended pipe that extends downward into the tank. LiquiSeal™ or Purge Control differential pressure air flow regulators are highly refined versions of the basic bubbler air control.