Endress+Hauer Ultrasonic measurement Time-of-Flight Prosonic FDU91F
007109-HW-ENDRESS-009
Overview
The FDU91F provides accurate, maintenance-free ultrasonic level and flow measurement with hygienic design options, high chemical resistance, and reliable performance in both liquid and solid applications.
Measuring principle
Ultrasonic
Characteristic / Application
Separated version with field housing or top hat rail housing for control cabinet instrumentation, 300 m in-between sensor and transmitter
Supply / Communication
4-wire (HART, PROFIBUS DP)
Accuracy
+/- 2 mm + 0.17% of measured distance
Ambient temperature
-40 °C ... 105 °C
(-40 °F ... 221 °F)
Process temperature
-40 °C ... 105 °C
(-40 °F ... 221 °F)
CIP: 30 min: 135 °C
(30 min: 275 °F)
Process pressure / max. overpressure limit
0.7 bar ... 4 bar abs
(10 psi ... 58 psi)
Main wetted parts
316L (fully welded IP68 / NEMA 6P)
Process connection
G / NPT 1", DN80 / 100, ASME 3" / 4"
Process connection hygienic
Tri-Clamp ISO2852, DN80 3 1/2", DN100 4"
Blocking distance
0.3 m (1 ft)
Max. measurement distance
Liquids: 10 m (33 ft),
Solids: 5 m (16 ft)
Communication
Transmitter:
4 ... 20 mA HART
PROFIBUS DP
Certificates / Approvals
ATEX, FM, CSA, IEC Ex, INMETRO, NEPSI, UK Ex
Design approvals
EN 10204-3.1
Hygienic approvals
3A
Components
Transmitter:
FMU90, FMU95
Application limits
Foam / high turbulence possible:
FDU92
For tank farms scanner:
FMU95
Designed for continuous non-contact measurement, the FDU91F ensures stable operation regardless of dielectric properties, density, humidity, or buildup. With measuring ranges up to 10m in liquids and 5m in solids, it is ideal for silos, belts, stockpiles, crushers, and open channel flow applications. Built-in temperature compensation ensures measurement accuracy, while fully welded 316L construction and Tri-Clamp hygienic process connections support the highest sanitary requirements. IP68 protection, long-distance transmitter mounting, and automatic detection with FMU90/FMU95 simplify commissioning and ensure reliable performance even in harsh environments.