Irrigation and water-treatment vented tanks
Irrigation reservoirs and atmospheric water-treatment process tanks operate at ambient pressure with mostly clean liquid. Ultrasonic level gives a low-cost continuous reading for scheduling, dosing and overflow protection.
Confirm the site problem, the Volivue approach, and the expected operating benefit before final selection.
Operators lack a continuous reading for dosing and overflow control on vented process tanks.
Ultrasonic sensor reports continuous level and percent fill for SCADA-driven dosing and alarms.
Better dosing accuracy and overflow protection without a pressure-rated instrument.
Atmospheric process tanks where dosing depends on level
Vented tanks across water-treatment trains, including coagulation, settling feed, filter backwash and irrigation reservoirs, run at ambient pressure with mostly clean water and modest temperature swings. The challenges are operational: levels move with dosing cycles, recirculation keeps the surface lightly disturbed, and overflow protection has to keep working even when the SCADA link is down.
These are textbook ultrasonic conditions, and a Volivue sensor adds continuous level to existing tanks without a pressure-rated instrument. The boundary to respect is the headspace: dosing chemistry that generates vapor or persistent foam above the water, or any move to a sealed, pressurized stage of the train, degrades the echo and justifies stepping up to radar after review.
From a single tank reading to dosing-grade data
Fit the sensor to the top nozzle or a bridge bracket, keep the blind zone above maximum level, and reserve clearance from dosing lances and recirculation returns whose plumes disturb the surface. Temperature compensation handles day-night swings; on outdoor reservoirs add a sun shield so the housing stays inside its rated range and reads consistently across seasons.
Continuous level and percent fill feed the dosing controller over 4-20 mA, relays provide hard-wired overflow and dry-run protection independent of the network, and RS485/Modbus brings every tank into SCADA or the Volivue dashboard. Commissioning a small treatment train of several tanks is usually a matter of days, not weeks, with no process shutdown.
Four checks before ordering for vented treatment tanks
- Map each tank empty distance, span and blind zone against the 0.3-15 m planning range before fixing nozzle positions.
- Confirm dosing chemicals do not create persistent foam or vapor in the headspace; if they do, flag the tank for radar review.
- Keep the beam path clear of dosing lances, recirculation plumes, mixers and any level switches already in the tank.
- Decide which protections must be hard-wired: overflow and dry-run relay set points should operate without SCADA.
Can one sensor handle both the level trend for dosing and the overflow alarm?
Yes. The 4-20 mA output carries the continuous trend for the dosing controller while the relay channel switches the overflow alarm independently. Keep the alarm relay hard-wired to the local panel so protection still operates if the bus or SCADA link fails.
Recirculation keeps the surface moving — will percent fill jump around?
Mild surface movement averages out in the echo filtering, so the trend stays usable for dosing. If the return line discharges directly under the sensor, the reading can wander; relocate the sensor or angle the return outlet, which is usually a one-hour mechanical fix during installation.
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.