Prosonic S FDU91F

Summary

Product identification

• Product Name: Prosonic S FDU91F
• Type: Ultrasonic sensor for level and flow measurement
• Manufacturer: Endress+Hauser
• Document Revision: TI01471F/00/EN/01.20, dated 2020-09-14

Application

• Level Measurement: Continuous, non-contact measurement of liquids and bulk solids in silos, on conveyor belts, in material stockpiles, and in crushers.
• Flow Measurement: Measurement in open flumes and measuring weirs.
• Maximum Measuring Range: 10 m (33 ft) for liquids; 5 m (16 ft) for bulk solids.

Features

• Integrated temperature sensor for time-of-flight correction.
• Hermetically welded PVDF sensor for chemical resistance.
• Suitable for harsh ambient conditions with separate transmitter installation (up to 300 m / 984 ft).
• Self-cleaning effect to minimize deposit build-up.
• Weather resistant and flood-proof (IP68).
• International Dust-Ex and Gas-Ex certificates available.

Technical Specifications

Input

• Blocking Distance: 0.3 m (1.0 ft). Signals within this range cannot be measured.

Measuring Range

• Attenuation: Factors influencing the effective sensor range include surface conditions (calm, wavy, turbulent, frothy), dust formation, filling curtains, and temperature differences.
  • Surface of liquid: 0 dB (calm) to 20 dB (very turbulent).
  • Bulk solids surface: 40 dB (hard, rough) to 60 dB (soft).
  • Dust: 0 dB (none) to 20 dB (major).
  • Filling curtain: 0 dB (none) to 20 dB (large volumes).
  • Temperature difference: 0 dB (up to 20 °C) to 20 dB (up to 80 °C).
• Range Chart: Provided to estimate the sensor range based on total calculated attenuation.

Operating Frequency

• 42 kHz

Power Supply

• Supply voltage is provided by the transmitter.

Process

• Process Temperature:
  • Non-Ex: Max. 135 °C (275 °F) for 30 min (Tri-Clamp or flush mounting).
  • Ex: –40 to +80 °C (–40 to +176 °F).
• Process Pressure: 0.7 to 4 bar (10.15 to 58 psi).

Mechanical Construction

• Dimensions: Various dimensions are shown for different connection types (FAU80 slip-on flange, G1 thread, NPT1 thread, Tri-Clamp).
• Weight: Approximately 1.6 kg (3.53 lb) including a 5 m (16 ft) cable.
• Materials:
  • Sensor housing: 316L (1.4404/1.4435)
  • Cable gland: PA
  • Pipe adapter: CuZn nickel-plated
  • O-ring: EPDM
  • Connecting cable: PVC

Environment

• Degree of Protection: IP68 / NEMA6P (tested for 24 h at 1.83 m (6 ft) under water).
• Vibration Resistance: DIN EN 60068-2-64; 1 (m/s²)²/Hz for 3x100 min.
• Storage Temperature: Identical to process temperature.
• Thermal Shock Resistance: Based on DIN EN 60068-2-14.
• Electromagnetic Compatibility: Meets EN 61326 series and NAMUR Recommendation EMC (NE 21). Designed for use in an "industrial environment" and meets class A requirements for interference emission.

Certificates and Approvals

• CE mark
• RoHS (2011/65/EU)
• RCM-Tick marking
• Ex approval (details available in Product Configurator)

Installation

Level Measurement Conditions

• Recommended distance to vessel wall: 1/6 of vessel diameter.
• Avoid mounting in the center of the vessel.
• Do not measure through the filling curtain.
• No internal fixtures in the signal beam.
• For bulk solids, align sensor perpendicular to the product surface using the FAU40 alignment unit.
• The lower edge of the sensor should be inside the vessel.
• Maximum level must not enter the blocking distance.

Flow Measurement Conditions

• Mount sensor upstream of the maximum upstream level (Hmax) plus blocking distance.
• Position sensor in the center of the channel or weir.
• Align sensor perpendicular to the water surface.
• Observe mounting distance to flume constriction or weir edge.
• Protect sensor from sun and precipitation with a weather protection cover.

Installation Options

• Nozzle mounting (conditions for nozzle and maximum lengths specified).
• Mounting with U-rail or bracket.
• Mounting with FAU40 alignment unit.
• Mounting with a 1" sleeve welded to a grating.
• Flush mounting with slip-on flange (with or without adapter flange).

Accessories

• Sensor extension cable: Maximum total length 300 m (984 ft). Order number: 71027743.
• Mounting bracket for ceiling mounting: Material 316L (1.4404). Order No.: 71093130.
• FAU40 alignment unit: For aligning sensor with bulk solids surface, swivel range 15°.
• IP66 protective housing for RNB130 power supply unit: Order number: 51002468.

Supplementary Documentation

• Technical Information (TI) and Operating Instructions (BA) for FMU90 and FMU95 transmitters are available.
• Description of Device Parameters (GP) are available.

Ordering Information

• Detailed ordering information is available via the Endress+Hauser website and Product Configurator.
• 5-point linearity protocol: Available for the complete measuring system (sensor + transmitter) when specified during ordering. Span is defined by Empty (E) and Full (F) calibration values.
  • E ≤ 10,000 mm (394 in).
  • F = 100 to 9,700 mm (3.94 to 382 in).
  • A ≥ 300 mm (11.8 in).

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Disclaimer: This extraction may miss figures, footnotes, or revisions. Contractual data must match the OEM PDF revision used on the project.

Official datasheet (PDF)

Lenntech datasheet mirror