Endress+Hauser TW251-G2BE5S00 | Levelflex TDR Level Transmitter, 4-20mA HART, Single Rod
Endress+Hauser TW251-G2BE5S00 Levelflex TDR level transmitter. 2-wire 4-20mA HART, single rod probe, -1...40 bar, -196...+400°C, for liquids in tanks & stilling wells.
Product Overview
The Endress+Hauser TW251-G2BE5S00 is a 2-wire guided wave radar (TDR/TDR – Time Domain Reflectometry) level transmitter from the Levelflex TW251 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
|
TW251-G2BE5S00
|
|
Product Family
|
Levelflex TW251 (Guided Wave Radar / TDR)
|
|
Measured Variable
|
Level (Distance, Volume, Interface — with dual 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 (configured in suffix G2BE5S00 — verify exact probe length from full code)
|
|
Process Connection
|
Flange / Thread (DN25…DN100 / 1"…4" — per order detail)
|
|
Max. Process Pressure
|
-1 … +40 bar (gauge)
|
|
Process Temperature
|
-196 … +400 °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 "G2BE5S00" represents a typical TW251 base configuration with 4-20mA HART and standard electronics). Always verify the complete type code for probe specification.
