Endress+Hauser Prosonic FDU90 – Compact Ultrasonic Sensor for Level and Flow Measurement
The Prosonic FDU90 is a non-contact ultrasonic sensor designed for continuous level measurement of liquids, pastes, sludges and bulk materials, as well as flow measurement in open channels and measuring weirs. Connected with Endress+Hauser FMU90 or FMU95 transmitters, it provides a reliable and cost-effective solution for ultrasonic measurement applications.
With a compact design, chemically resistant PVDF sensor material and separate installation from the transmitter, the FDU90 is suitable for applications where space, environmental protection and long-term reliability are important.
Accurate Time-of-Flight Ultrasonic Measurement
The FDU90 uses the proven time-of-flight ultrasonic measuring principle. The sensor sends ultrasonic pulses toward the medium surface and calculates the level based on the return signal time.
Because measurement is performed without contact with the medium, the sensor avoids mechanical wear and contamination-related problems commonly found in contact measurement technologies.
Key performance:
Measuring principle: Ultrasonic time-of-flight
Accuracy: ±2 mm + 0.17% of measured distance
Maximum measuring range:
Liquids: up to 3 m
Solids: up to 1.2 m
Blocking distance: 0.07 m
Process temperature: –40 to +80 °C
Process pressure: 0.7 to 4 bar abs
Sensor material: PVDF
Protection rating: IP68 / NEMA 6P
Communication (via transmitter): HART, PROFIBUS DP
Suitable for Liquids, Sludges and Bulk Solids
The Prosonic FDU90 provides stable measurement for a wide range of industrial media and is not affected by changes in:
Dielectric constant
Density
Humidity
Medium conductivity
The ultrasonic sensor is suitable for applications such as:
Water and wastewater level measurement
Chemical storage tanks
Sludge tanks
Silos and hoppers
Bulk material storage
Open channel flow measurement
Measuring weirs and channels
Reliable Performance in Difficult Installation Conditions
The FDU90 is designed as a separated sensor solution, allowing installation away from the transmitter.
The distance between sensor and transmitter can reach up to 300 m, providing flexibility for large tanks, outdoor installations and applications where the electronics need to be protected from harsh environments.
Its hermetically welded PVDF construction provides excellent chemical resistance, while the sensor design helps reduce material buildup through a self-cleaning effect.
Integrated Temperature Compensation for Stable Measurement
Ultrasonic measurement accuracy can be influenced by temperature variations because sound velocity changes with temperature.
The FDU90 includes an integrated temperature sensor that automatically compensates for temperature effects, helping maintain reliable measurement accuracy even when ambient conditions change.
Flexible Connection with Endress+Hauser FMU Transmitters
The FDU90 works together with Endress+Hauser ultrasonic transmitters:
This separated system design allows users to select the most suitable transmitter installation method, including field housing or DIN rail mounting solutions for control cabinets.
Explosion Protection and Industrial Applications
The FDU90 is available with international hazardous area approvals, making it suitable for applications where explosion protection is required.
Typical industries include:
Water & wastewater
Chemical processing
Mining and minerals
Power plants
Bulk material handling
Environmental engineering
Frequently Asked Questions
What is the Prosonic FDU90 used for?
The FDU90 is used for continuous, non-contact level measurement of liquids, sludges, pastes and bulk solids, as well as open channel flow measurement.
What is the maximum measuring distance of the FDU90?
The maximum measuring distance is 3 m for liquids and 1.2 m for solids.
Does the FDU90 contact the measured medium?
No. The FDU90 uses a non-contact ultrasonic measuring principle, which helps reduce maintenance requirements.
What transmitter is required for the FDU90?
The FDU90 is designed to connect with Endress+Hauser FMU90 or FMU95 ultrasonic transmitters.
Can the FDU90 be used outdoors?
Yes. With IP68 / NEMA 6P protection and robust PVDF construction, the sensor is suitable for demanding outdoor environments.
Why choose ultrasonic measurement instead of radar?
Ultrasonic measurement is a practical solution for many water, wastewater and bulk material applications where a cost-effective, reliable non-contact technology is required.
