Non-Contact Sensing
Mounted above the liquid surface with zero contact, zero mechanical wear, and zero buildup on submerged components.
Level Instruments
Ultrasonic Level Transmitter
Non-Contact Continuous Acoustic Echo Level Measurement
Accurate. Non-Contact. Built for Demanding Liquid Levels.
The FlowDo Ultrasonic Level Transmitter provides continuous, non-contact liquid level measurement for open tanks, process vessels, sumps, reservoirs, and drainage basins. With intelligent echo-processing algorithms and automatic temperature compensation, it delivers highly dependable 4–20 mA output.
ULTRASONIC ECHO
Technology
NON-CONTACT
Measurement Type
UP TO 15 METERS
Measuring Range
4–20 mA / RS485
Output & Protocol
Product Overview
Dependable Non-Contact Acoustic Sensing
Continuous ultrasonic level measurement engineered for industrial liquid storage, water management, and wastewater vessels.
The FlowDo Ultrasonic Level Transmitter emits high-frequency acoustic sound pulses from its top-mounted transducer toward the liquid surface. The sound waves travel through the air, reflect off the liquid interface, and return to the transducer receiver.
The on-board microcomputer precisely measures the time delay between transmission and reception, automatically applies speed-of-sound temperature compensation, and calculates the exact tank liquid level: Level = Tank Reference Height − Measured Distance. Because no sensor elements touch the liquid, maintenance and chemical fouling are virtually eliminated.
Key Engineering Highlights
- 100% non-contact sensing with zero immersion in process liquids
- Built-in temperature sensor for automatic speed-of-sound compensation
- Measuring spans up to 5 m, 10 m, and 15 meters for small to large vessels
- Rugged PVDF / Polypropylene wetted acoustic transducer face
- Standard 4–20 mA current loop output with optional RS485 Modbus RTU
Verified catalogue data
Technical Specifications
Technical parameters for FlowDo Ultrasonic Level Transmitters.
Brand / Manufacturer
FlowDo Process Instruments
Product Name
FlowDo Ultrasonic Level Transmitter
Measurement Type
Continuous Non-Contact Liquid Level (0–100%)
Operating Principle
Acoustic Echo Time-of-Flight with Temperature Compensation
Measuring Range
0–5 m / 0–10 m / 0–15 m (Model Dependent)
Blind Zone (Dead Zone)
0.25 m to 0.5 m (depending on model range)
Accuracy
±0.25% to ±0.5% of Full Scale
Output Signal
4–20 mA DC (2-Wire / 4-Wire) / RS485 Modbus RTU
Power Supply
24 V DC (18–30 V DC) or 230 V AC (Optional)
Transducer Material
Polypropylene (PP) / PVDF (Corrosion Resistant)
Process Connection
G2", 2" NPT Male Thread or Universal Bracket / Flange Mount
Operating Temperature
-20°C to +60°C
Enclosure Rating
IP65 / IP66 Weatherproof Polycarbonate / Cast Aluminum
Product design
Key Features
Non-contact acoustic technology engineered for reliable water and chemical tank monitoring.
Auto Temperature Compensation
Integrated temperature sensor constantly calibrates sound velocity across changing weather and diurnal temperature swings.
Configurable 5 m / 10 m / 15 m Spans
Multiple frequency models optimize beam angle, acoustic power, and resolution for small tanks up to deep reservoirs.
PVDF Chemical Resistant Face
Transducer housing options in Polypropylene or PVDF resist corrosive fumes, acids, and wastewater gases.
4–20 mA & RS485 Modbus
Standard analog 4–20 mA current loop output with optional RS485 Modbus RTU for digital plant bus networks.
Easy Top Threaded Installation
Standard G2" / 2" NPT male thread or universal mounting brackets for open channels and sump basins.
Industries and processes
Applications
Non-contact continuous liquid level monitoring across industrial water and process facilities.
Water Storage Tanks & Reservoirs
Raw water tanks, treated water reservoirs, municipal water towers, and overhead industrial storage vessels.
Effluent & Sewage Sumps
Wastewater collection sumps, lift stations, clarifier basins, and equalization tanks in ETP and STP plants.
Chemical & Dosing Tanks
Chemical storage tanks, acid dosing vessels, and water treatment coagulant tanks with PVDF transducer face.
Open Channel Flow & Basins
Weirs, flumes, stormwater drainage channels, intake canals, and environmental monitoring stations.
Cooling Tower Makeup Basins
Cooling tower cold water basins, makeup water sumps, and industrial condenser water reservoirs.
Packaged Water Treatment Skids
OEM integration in reverse osmosis (RO) skids, demineralization (DM) plants, and filtration units.
System Integration
From Tank Level to Process Control
Seamless signal integration from non-contact field measurement into plant automation architecture.
Ultrasonic Level Transmitter
Non-Contact Field Sensor
↓
Continuous Measured Level
Calibrated Process Variable
↓
4–20 mA / Supported Output
Standard Industrial Signal
↓
Local Indicator
FlowDo Level / Process Indicator
PLC / Controller
Pump Automation & Alarm Logic
↓
SCADA & Plant Monitoring
Real-time telemetry, automated pump interlocks & analytics
Level Technology Overview
Choose the Right Continuous Level Technology
Comparison of primary FlowDo continuous level measurement instruments.
Ultrasonic Transmitter
- Principle
- Sound-wave / acoustic echo
- Installation
- Tank top
- Process Contact
- Non-contact
- Best Suited
- Compatible open/closed tanks where ultrasonic conditions are suitable.
Radar Level Transmitter
- Principle
- Electromagnetic radar / microwave
- Installation
- Tank top (Flanged / Horn antenna)
- Process Contact
- Non-contact for applicable models
- Best Suited
- Challenging process vessels, storage tanks, and non-contact continuous monitoring.
Hydrostatic Transmitter
- Principle
- Liquid hydrostatic pressure
- Installation
- Submerged / pressure sensing
- Process Contact
- Yes (sensor exposed to liquid)
- Best Suited
- Compatible liquids where hydrostatic measurement is appropriate (sumps, borewells, tanks).
Technology selection should consider medium characteristics, tank geometry, installation access, measurement range, temperature, pressure, atmosphere and required accuracy.
Product Range
Available Level Transmitter Configurations
FlowDo level instruments can be selected according to measurement range, process connection, material compatibility, output and installation requirements.
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View details & specs →Frequently Asked Questions
Frequently Asked Questions
Common questions regarding ultrasonic level measurement, installation and configuration.
What is an ultrasonic level transmitter?
An ultrasonic level transmitter uses sound pulses and their reflected echoes to determine the distance to a material surface and calculate the corresponding level.
Does the ultrasonic sensor contact the liquid?
In a typical ultrasonic installation, the transmitter is mounted above the measured surface and performs the measurement without continuous contact with the liquid.
Can it be used for water tanks?
Yes, ultrasonic level measurement is commonly applicable to water storage and similar tank applications when the tank geometry, measurement range and environmental conditions are suitable.
Can the transmitter connect to a PLC or SCADA system?
Compatible FlowDo configurations can provide industrial process outputs for integration with monitoring or control systems. Available output and communication options should be selected according to the specific model.
What measurement range should I select?
The required range depends on tank height, maximum and minimum level, mounting position and the instrument's required blind zone. The product should be configured for the actual installation.
Can ultrasonic measurement be affected by foam or turbulence?
Heavy foam, turbulence, vapour, obstructions and certain process conditions can affect ultrasonic echo quality, so these conditions should be reviewed during instrument selection.
Need Help With Level Measurement?
Configure the Right Ultrasonic Level Transmitter for Your Application
Share your tank dimensions, process medium, measurement range, temperature, pressure, process connection and output requirements with FlowDo to identify a suitable configuration.
For faster selection, provide: Tank Height • Measured Medium • Range • Temperature • Pressure • Connection • Blind Zone Consideration • Output Requirements