Municipal wastewater basins and sumps
Open wastewater basins, lift stations and sumps need continuous level for pump control. A non-contact ultrasonic liquid level sensor keeps the electronics above the dirty, abrasive water so there is no fouling on a wetted probe.
Confirm the site problem, the Volivue approach, and the expected operating benefit before final selection.
Submerged probes and floats foul quickly in gritty municipal wastewater.
Non-contact ultrasonic measurement from above the basin avoids contact with solids and grit.
Reliable pump-control level with far less cleaning and downtime than wetted sensors.
Grit, grease and foam pockets above a moving water line
Lift stations, inlet channels and wastewater sumps combine gritty, abrasive water with floating grease, patchy surface foam and bursts of turbulence from incoming flow. Wetted floats and submerged probes foul within weeks in this service, while a non-contact ultrasonic liquid level sensor keeps every component above the water line, so the medium never touches what measures it.
Ultrasonic remains the right choice as long as the foam stays patchy and the headspace is open to atmosphere. A continuous foam blanket, heavy hydrogen-sulfide vapor in a sealed wet well, or surface aeration that whips the water into froth all absorb the acoustic pulse; such stations belong in an application review, where a Volivue radar transmitter is usually the safer selection.
Pump control wired the way operators already think
Install the sensor on a cantilever bracket over the wet well, clear of the inlet splash zone and benching, with the blind zone reserved above the highest surcharge level. In confined sumps check the beam cone against the wall: a narrow well may need the sensor centered so that pump guide rails, lifting chains and cable trays stay outside the cone and cannot return false echoes.
Relay outputs map directly to lead/lag pump start-stop and the high-level alarm, the 4-20 mA loop trends level in the existing telemetry RTU, and RS485/Modbus can publish level to a Volivue dashboard for multi-station overview. A typical lift-station retrofit, bracket included, is commissioned in about a day per site without stopping the pumps.
Four checks before ordering for a wastewater lift station
- Measure the maximum surcharge level and confirm the blind zone keeps the sensor face above it with margin.
- Survey the wet well for in-beam obstacles such as guide rails, chains, cables and benching, then pick a mounting point with a clean cone to the water.
- Classify the foam and grease behavior: a patchy film is acceptable for ultrasonic, while a persistent blanket points to radar.
- Define pump-control logic up front: relay set points for lead/lag/stop, the alarm level, and the signals the RTU or SCADA expects.
Will foam on the wastewater surface make the level read low or drop out?
Thin, broken foam usually still returns a workable echo, though the reading may sit at the foam surface rather than the clear water line. A continuous, stiff foam blanket absorbs the pulse and can cause echo loss, so report persistent foaming during the application review; that is typically where we recommend radar instead.
How do we stop false echoes from pump rails and chains in a narrow wet well?
Position the sensor so the beam cone clears all fixed steelwork first, then use the commissioning software to map and suppress any residual fixed echo. If the well is too narrow for a clean cone, a small repositioning of the bracket is almost always cheaper and more reliable than filtering a bad mounting point.
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.