Work out level sensor range instantly with clear inputs, formula shown and shareable results.
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.
Level from distance
level = tank height - measured distance; volume = level x cross-sectional area
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.
Use a separate point-level switch, or mount the sensor in a nozzle so the dead band sits above the maximum working level.