Endress+Hauser FMX21-1CE620 | Levelflex M Guided Wave Radar Transmitter, 2-Wire 4-20mA HART
Endress+Hauser FMX21-1CE620 Levelflex M guided radar (TDR) level transmitter. 2-wire 4-20mA HART, single rod probe, -1...40 bar, -196...+450°C, for liquids in tanks & stilling wells.
Product Overview
The Endress+Hauser FMX21-1CE620 is a 2-wire guided microwave (TDR/TDR – Time Domain Reflectometry) level transmitter from the Levelflex M FMX21 series, designed for continuous level measurement of liquids, pastes, and interface layers in storage tanks, process vessels, and stilling wells. This variant features a single rigid/flexible rod probe, 4-20mA HART output, and is suitable for applications with turbulent surfaces, foam, or changing dielectric constants where non-contact radar may struggle. It offers high accuracy (±3 mm) and is unaffected by changing media properties, dust, or vapor.
Technical Specifications (Measurement & Electrical)
|
Parameter
|
Specification
|
|
Model / Order Code
|
FMX21-1CE620
|
|
Product Family
|
Levelflex M FMX21 (Guided Wave Radar / TDR)
|
|
Measured Variable
|
Level (Distance, Volume, Interface — with second probe or known dielectric)
|
|
Measuring Principle
|
TDR (Time Domain Reflectometry) — Guided Microwave Pulse
|
|
Measuring Range (Probe Dependent)
|
Up to 20 m (flexible rope) / 6 m (rigid rod)
|
|
Accuracy
|
±3 mm (probe + electronics)
|
|
Dead Zone (Top/Bottom)
|
Probe-specific (typically 50–300 mm top dead zone)
|
|
Output Signal
|
4…20 mA with HART 7 (2-wire loop powered)
|
|
Supply Voltage
|
18…35 V DC (loop powered)
|
Technical Specifications (Mechanical & Process)
|
Parameter
|
Specification
|
|
Probe Type
|
Single Rod / Single Rope (Code E6xx — verify exact probe length from full config)
|
|
Process Connection
|
Flange / Thread (DN25…DN100 / 1"…4" — per order detail)
|
|
Max. Process Pressure
|
-1 … +40 bar (gauge)
|
|
Process Temperature
|
-196 … +450 °C (depends on probe & seal version)
|
|
Wetted Parts Material
|
316L (1.4404) / Hastelloy C-276 / Tantalum (probe-specific)
|
|
Housing Material
|
Aluminum (coated) / Stainless Steel (optional)
|
|
Protection Rating
|
IP66/IP67 / NEMA 4X (Transmitter Housing)
|
|
Approvals / Area
|
Non-hazardous / optionally Ex d / Ex i (check suffix)
|
Key Features
-
TDR Technology — Immune to Process Conditions: Unaffected by vapor, foam, turbulence, dust, or dielectric constant changes down to εᵣ > 1.4 — outperforms free-space radar in challenging tank conditions.
-
No Moving Parts: Solid-state measurement with no mechanical wear, ideal for sticky, coating, or crystallizing media (with appropriate probe choice — coated or segmented rods available).
-
HART 7 Communication: Full digital communication over the 4-20mA loop for remote configuration, diagnostics, and false-echo suppression (mapping tank obstructions).
-
Flexible Probe Options: Supports rigid rods (short tanks), flexible ropes with weight (deep tanks), and coaxial/cage probes (high turbulence or low dielectric).
Applications
-
Storage Tank Gauging: Continuous level of fuels, solvents, chemicals in above/below-ground tanks.
-
Process Vessels: Level in reactors, separators, and boiling pans — including under vacuum or high pressure.
-
Interface Measurement: Oil/water or solvent/aqueous layer detection (requires known dielectric contrast and dual-probe or single-probe + reference).
-
Problematic Media: Foaming liquids, turbulent surfaces, low-dielectric hydrocarbons where non-contact radar fails.
Note: The exact probe length, process connection (flange rating/size), and seal material are defined by the full 5th–8th character group in the order code (here "1CE620" represents a typical FMX21 base configuration with 4-20mA HART and standard electronics). Always verify the complete type code for probe specification.
