Monitoring the level of liquid can be accomplished through the use of a pressure transducer. The density of the liquid and its height create pressure on the diaphragm of the pressure transducer to generate an accurate and cost effective level measurement. Generally, pressure transducers can be used for level measurement from 10 inches of water column, up to 10,000 PSI (700 bar).
Pressure transducers can either be submerged in the liquid or mounted externally. Submersible pressure transducers can be installed freely or with a rigid conduit to monitor the hydrostatic liquid above it. As the liquid level decreases, the output decreases. Submersible sensors are commonly used in vented tanks such as diesel tanks or for water and waste water level.
Pressure transducers can also be mounted to the side or bottom of the tank through a separate line, feed line or drain line. This design can cost less, as it doesn't require a special cable, and installation is quick. Differential pressure transducers can be used on vented or sealed tanks, measuring the difference in pressure between the top and bottom of the tank.
Custom Liquid Level Sensors
AST manufactures a variety of custom liquid level sensors and solutions for OEM applications. If you find a product that is close to a solution, but not exactly what you hoped for, please contact us and an engineer will follow up with you regarding our custom capabilities for pressure ranges, outputs, sizes and materials.