Hydrostatic Pressure to Level Calculator
Convert the reading of a hydrostatic level sensor (submersible probe or pressure transmitter at the tank bottom) into liquid level, and find the transmitter range for a given level span.
- h = P ÷ (SG × 9806.65) = 25,000 ÷ 9,806.65 = 2.549 m
- Level = h + sensor height = 2.649 m
Hydrostatic Level Formula
Level = h + sensor mounting height
ρwater × g = 9806.65 Pa per metre, so 1 m of water reads 98.07 mbar.
Worked example
A probe 0.1 m above the tank bottom reads 250 mbar in water: h = 25,000 ÷ 9806.65 = 2.549 m, level = 2.649 m.
Frequently Asked Questions
How does a submersible level sensor work?
It measures the hydrostatic pressure of the liquid above it, which is proportional to depth and density.
What happens if the density changes?
The level reading changes in proportion. A 2 % density error gives a 2 % level error.
Can I use this in a closed tank?
Only if the tank is vented. Pressurised tanks need a DP transmitter or two sensors.
Learn more on the blog
Basics of level measurement
A practical, field focused guide on instrumentationblog.in that explains the theory behind this calculator and how engineers apply it on real plants.
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