Level Sensor Range Calculator

Work out level sensor range instantly with clear inputs, formula shown and shareable results.

About Level Sensor Range Calculator

A downward-looking level sensor measures distance to the surface, so level is tank height minus that distance. The dead band immediately below the sensor cannot be measured, which caps the usable high-level reading and must be allowed for when setting high alarms.

Formula

Level from distance

level = tank height - measured distance; volume = level x cross-sectional area

Worked example

With the default values below, Level Sensor Range Calculator returns Liquid level of 1.90. Change any input above and every figure here is recalculated in your browser.

Inputs used

Tank height: 3 m
Sensor dead band: 0.3 m
Measured distance to surface: 1.1 m
Tank cross-sectional area: 4.5 m²

Results

Liquid level: 1.90 m
Volume in tank: 8.55 m³
Usable measuring range: 2.70 m
Tank fill: 63.33% %

Step by step

1Values used
2Level from distance
3Liquid level= 1.90 m
4Volume in tank= 8.55 m³
5Usable measuring range= 2.70 m
6Tank fill= 63.33 %

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

What causes the dead band?

Ultrasonic and radar sensors need time for the transmit burst to finish before listening, so targets within roughly 0.2-0.5 m cannot be resolved.

How do I get a high-level alarm above the dead band?

Use a separate point-level switch, or mount the sensor in a nozzle so the dead band sits above the maximum working level.