Hydrostatic Level Measurement

Hydrostatic Level Measurement

Hydrostatic level measurement determines level by measuring the pressure created by a liquid column. A pressure transmitter at (or near) the vessel bottom senses hydrostatic head, and the level is calculated from that pressure using fluid density. In closed or pressurized vessels, differential pressure configurations can be used to remove vapor-space pressure influence and isolate true liquid head.

The method is valued for stable measurement in conditions that disturb surface-based technologies. Foam, turbulence, splashing, and vapor space variability generally do not prevent accurate hydrostatic sensing because the measurement is based on static pressure, not a surface echo. With correct materials and sealing strategy, it is applicable to corrosive or dirty services where non-contact methods may struggle.

Key engineering considerations include density variability, temperature effects, and the need for accurate reference conditions. For open tanks, atmospheric reference is required; for pressurized vessels, DP arrangements or appropriate compensation strategies are used. Impulse line plugging, diaphragm seal selection, and mounting elevation must be addressed to avoid offsets and drift in slurry or crystallizing services.

Hydrostatic level is common in sumps, wells, basins, and process tanks across water and wastewater, chemical processing, and utilities. It is also widely applied to dosing and batching vessels, scrubbers, and storage tanks where level-to-volume conversion is straightforward and where continuous, dependable measurement is required.

These transmitters integrate seamlessly into control systems for continuous indication, pump control, and alarming. With disciplined installation (sealing, venting, and maintenance access) and density-aware configuration, hydrostatic level measurement delivers a strong balance of reliability, cost effectiveness, and application breadth.

Field Instruments & Controls, Inc. an exclusive authorized representative of sales and service for Endress+Hauser.