Endress+Hauser Prosonic FDU93 – Long-Range Ultrasonic Sensor for Challenging Level Applications

The Prosonic FDU93 is a high-performance ultrasonic sensor designed for continuous, non-contact level measurement of liquids, pastes, sludges and bulk solids, as well as open channel flow measurement. Connected with Endress+Hauser FMU90 or FMU95 transmitters, it provides a reliable solution for large tanks, silos and demanding industrial environments.

With a measuring range of up to 25 m for liquids and 15 m for solids, the FDU93 is optimized for applications requiring extended measurement distances while maintaining stable and accurate performance.

Reliable Measurement Without Medium Contact

The Prosonic FDU93 uses the proven ultrasonic time-of-flight measuring principle. The sensor sends ultrasonic pulses toward the medium surface and calculates the level based on the time required for the echo signal to return.

Because the sensor does not contact the process medium, it avoids problems such as mechanical wear, contamination and corrosion, making it a practical solution for demanding level measurement applications.

Key performance:

• 
  Measuring principle: Ultrasonic time-of-flight
  
• 
  Accuracy: ±2 mm + 0.17% of measured distance
  
• 
  Maximum measuring range:
  
  
  Liquids: up to 25 m
  
  
  Solids: up to 15 m
  
  
  
• 
  Blocking distance: 0.6 m
  
• 
  Process temperature: –40 to +95 °C
  
• 
  Process pressure: 0.7 to 3 bar abs
  
• 
  Sensor material: UP (unsaturated polyester)
  
• 
  Protection rating: IP68 / NEMA 6P
  
• 
  Communication: Via FMU90/FMU95 transmitter with HART or PROFIBUS DP
  

Designed for Large Tanks and Bulk Material Measurement

The FDU93 is particularly suitable for applications where conventional level sensors may have limitations due to long measuring distances or difficult installation conditions.

Typical applications include:

• 
  Large storage tanks
  
• 
  Water and wastewater basins
  
• 
  Chemical process vessels
  
• 
  Bulk material silos
  
• 
  Stockpiles
  
• 
  Crushers and conveyors
  
• 
  Open channel flow measurement
  
• 
  Measuring weirs and channels
  

The measurement principle remains unaffected by changes in:

• 
  Dielectric constant
  
• 
  Density
  
• 
  Humidity
  

This allows reliable operation across different process materials.

Maintenance-Friendly Design with Self-Cleaning Effect

The sensor design of the FDU93 helps minimize material buildup on the measuring surface.

This self-cleaning effect improves measurement reliability in applications involving:

• 
  Dusty environments
  
• 
  Sludge and wastewater
  
• 
  Sticky materials
  
• 
  Condensation
  
• 
  Outdoor installations
  

The robust construction and IP68 protection rating allow reliable operation even in harsh environmental conditions.

Flexible Installation with Remote Transmitter

The Prosonic FDU93 uses a separated sensor and transmitter design, allowing flexible installation in industrial plants.

The sensor can be installed up to 300 m away from the transmitter, enabling the electronics to be mounted in a more convenient and protected location.

Compatible transmitters include:

• 
  Endress+Hauser FMU90
  
• 
  Endress+Hauser FMU95
  

This separated architecture is especially useful for:

• 
  Outdoor measurement points
  
• 
  Large storage facilities
  
• 
  Hazardous environments
  
• 
  Control room installation requirements
  

Stable Accuracy with Temperature Compensation

Changes in temperature can influence ultrasonic signal speed. The FDU93 integrates a temperature sensor to automatically compensate for temperature effects.

This helps maintain accurate measurement performance even when environmental temperatures fluctuate.

Suitable for Hazardous Area Applications

The Prosonic FDU93 supports international explosion protection approvals, making it suitable for industrial environments where dust or gas explosion protection is required.

Available approvals include:

• 
  ATEX
  
• 
  FM
  
• 
  CSA
  
• 
  IECEx
  
• 
  INMETRO
  
• 
  NEPSI
  
• 
  UK Ex
  

Typical industries include:

• 
  Oil & Gas
  
• 
  Chemical Processing
  
• 
  Water Treatment
  
• 
  Mining
  
• 
  Power Generation
  
• 
  Bulk Material Handling
  

Frequently Asked Questions

What is the Endress+Hauser Prosonic FDU93 used for?

The FDU93 is used for continuous non-contact level measurement of liquids, pastes, sludges and bulk solids, as well as open channel flow measurement.

What is the maximum measuring range of the FDU93?

The FDU93 can measure up to 25 m for liquids and 15 m for solids.

Does the FDU93 contact the measured medium?

No. The FDU93 uses a non-contact ultrasonic measuring principle, reducing maintenance requirements and improving long-term reliability.

Which transmitter works with the FDU93?

The FDU93 is designed for connection with Endress+Hauser FMU90 and FMU95 ultrasonic transmitters.

Can the FDU93 be installed outdoors?

Yes. The IP68 protection rating and robust design allow reliable operation in demanding outdoor environments.

Why choose FDU93 instead of a shorter-range ultrasonic sensor?

The FDU93 is designed for applications requiring longer measuring distances, making it ideal for large tanks, silos and bulk material storage areas.