Clean water and utility liquid tanks
Vented water break tanks, buffer tanks and utility liquid storage have a calm, clean surface with little vapor. A non-contact ultrasonic liquid level sensor reads the level from the top nozzle without wetted parts, so there is nothing to corrode or recalibrate.

Confirm the site problem, the Volivue approach, and the expected operating benefit before final selection.
Float switches stick and manual dipping wastes labor on routine clean-water tanks.
Top-mounted ultrasonic sensor measures distance to the calm liquid surface and outputs continuous level.
Continuous, maintenance-light level with no wetted parts and a fast, low-cost retrofit.
Calm, clean surfaces are where ultrasonic earns its keep
Vented break tanks, buffer vessels and fire-water reserves hold clean water at ambient pressure, with a calm surface and almost no vapor load. The acoustic risks come from the surroundings rather than the water: a fill stream rippling the surface directly under the sensor, a ladder or pipe inside the beam path, and condensation forming on the transducer face in unheated plant rooms on cold nights.
Within these conditions a Volivue ultrasonic liquid level sensor is the economical choice, since the echo returns cleanly from a flat water surface across the 0.3-15 m planning range. The upgrade trigger is environmental, not the medium: if the tank is later sealed, heated until it steams, or dosed with foaming agents, echo quality degrades and the application should be reviewed for a radar transmitter instead.

A top nozzle, a bracket and one afternoon of wiring
Mount the sensor on the top nozzle or a rigid bracket so the transducer face sits parallel to the water surface, keep the model-specific blind zone above the maximum fill line, and route the beam clear of inlet pipes, ladders and tank walls. Built-in temperature compensation corrects the speed of sound, but the housing should still be shaded from direct summer sunlight to limit gradient error.
The 4-20 mA loop feeds the existing PLC, relay outputs handle high-level overflow alarm and low-level pump cut-off locally, and RS485/Modbus carries level and percent fill to SCADA or the Volivue dashboard. A single-tank retrofit is typically commissioned within one working day, since no tank entry, draining or wetted-part installation is needed.

Four checks before ordering for a clean-water tank
- Confirm the distance from sensor face to lowest measured level stays inside the 0.3-15 m planning range, with the blind zone above maximum fill.
- Verify a free acoustic path: no fill stream, ladder, pipe or agitator inside the beam cone between nozzle and water surface.
- Check the plant-room temperature span and condensation risk; allow a drip loop on cabling and shading if the roof is unheated.
- List the required outputs: 4-20 mA loop, relay set points for pump control, and the RS485/Modbus register map if SCADA reads the tank.
Will the reading drift when the fill valve opens and the surface ripples?
Light ripple widens the echo slightly but rarely shifts the averaged trend, and the sensor filtering smooths it further. Position the sensor away from the direct fill stream; if turbulence is constant, add a simple stilling section or enable a damped output so pump-control set points stop chattering.
Does condensation on the transducer face matter in winter?
Short-lived droplets are largely self-clearing because the transducer vibrates, but a persistent film in cold, humid rooms can attenuate the echo. Mount the face pointing straight down, avoid dead-air pockets, and check the face during seasonal inspection; heavy permanent condensation is a signal to review radar.
Five checks that decide the ultrasonic model, mounting, configuration and output scope.
Application review
We review medium, tank, vapor and foam to confirm ultrasonic fits or recommend radar.
Model and mounting selection
We size range, blind zone, output and nozzle or bracket mounting for your tank.
Configuration and tank profile
We set empty distance, blind zone and linearization so readings match real fill.
Commissioning support
We support installation, signal verification and PLC / SCADA integration on site or remotely.
Lifecycle support
We provide spares, documentation and guidance for expansions and technology changes.
Selection questions for engineers, procurement teams and site maintenance.
What is an ultrasonic liquid level sensor?
It is a non-contact sensor that emits an ultrasonic pulse from the top of a tank, times the echo from the liquid surface and converts that distance into continuous level, percent fill or a 4-20 mA / relay / RS485 signal, with no part touching the liquid.
When should I choose radar instead of ultrasonic?
Choose a Volivue radar liquid level sensor when the headspace has heavy steam or vapor, dense foam, condensation, the vessel is pressurized or sealed, or the area is classified hazardous. Radar is unaffected by vapor and works under pressure, where ultrasonic echoes weaken.
What liquids and tanks suit ultrasonic level?
Clean, vented, atmospheric tanks: water, wastewater, utility liquids and clean low-vapor chemicals with a stable surface. It is the cost-effective choice when pressure rating and vapor immunity are not required.
Does it measure volume or weight?
It measures level and distance to the surface. Volume or percent fill is derived from tank geometry and known density. It does not sense weight and is not a weighing instrument.
What is the blind zone?
The blind zone is a minimum distance below the sensor face where measurement is not reliable. The sensor must be mounted so the highest liquid level stays below this zone; the exact value is model-specific.
What outputs and protocols are available?
Standard outputs are 4-20 mA, relay thresholds and RS485 / Modbus, integrating directly with PLC, SCADA and the optional Volivue dashboard. An API can expose data to other plant systems.
Can it be used in hazardous areas?
Hazardous-area suitability is reviewed per project. Classified zones often require a different protection concept or a radar instrument; we confirm requirements before quoting and do not assume an approval that has not been verified.
Request an ultrasonic liquid level review
Tell us about your tanks, liquids and signal needs. We review the application, confirm whether ultrasonic suits the medium and return models, mounting and outputs – or recommend a radar liquid level sensor when conditions require it.