The principle is based to use a differential pressure transmitter or relative pressure, equipped with a process connection suitable for level measurements.
The use of a pressure transmitter for the level measurement is an economical solution in particular for the chemical and petrochemical industries. The transmitter can be with direct or capillary mounted diaphragm seals.
These instruments can handle extreme chemical and mechanical loads and are no sensitive to electromagnetic interference. They can be used for all liquids, corrosive or not, and for closed or open tanks..
The differential pressure transmitters are used for the level measurement of pressurized tanks.
The gauge pressure transmitters are used for the level measurement of open tanks (top of tank at atmospheric pressure).