Technical Characteristics and Thermal Resilience
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Extreme Temperature Range: The FTL64 is designed to operate safely in process temperatures from -60 °C to +280 °C. This makes it ideal for thermal oil systems, steam applications, and chemical reactors. For aggressive media at high temperatures, an optional PFA coating is available (up to +230 °C).
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High-Pressure Capability: The robust sensor design withstands process pressures up to 100 bar, providing stability in high-pressure steam or pressurized chemical vessels.
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SIL 2/3 Functional Safety: As a safety-by-design instrument, it is 3rd-party approved for use in high-integrity safety loops. It features a gas-tight feedthrough—the “Second Line of Defense”—to protect the environment and electronics if the primary sensor diaphragm is breached.
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Heartbeat Technology: This integrated diagnostic suite provides continuous self-monitoring. It can detect sensor damage, heavy buildup, or corrosion in real-time. Verification can be performed at any time via digital communication without interrupting the process.
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Guided Digital Proof Testing: Compliance with SIL, WHG, and API 2350 is simplified through guided wizards in the SmartBlue App. This allows for fast, documented testing of the safety loop from outside the vessel, reducing operational downtime.
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Reliable Vibronic Principle: The switching point remains accurate regardless of changing media properties, gas bubbles, foam, or vibrations. It handles high viscosities up to 10,000 mm2/s (cSt), ensuring performance in thick, hot fluids.
Technical Specification Matrix
| Feature | Technical Details |
| Measuring Principle | Vibronic (Tuning Fork) |
| Device Design | High-temperature extension tube version |
| Process Temperature | -60 °C to +280 °C (PFA coating: up to 230 °C) |
| Process Pressure | -1 to +100 bar (PFA coating: up to 40 bar) |
| Max. Viscosity | 10,000 $mm^2/s$ ($cSt$) |
| Output Signal | FEL61 (AC), FEL62 (DC-PNP), FEL64 (Relay), FEL68 (NAMUR), IO-Link |
| Safety & Compliance | SIL 2/3, WHG, API 2350, ATEX, IECEx, Marine |
Primary Applications
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Thermal Oil Systems: Reliable level monitoring in heaters and heat exchangers where temperatures exceed standard sensor limits.
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High-Pressure Steam Boilers: Acting as a low-level or high-level alarm in steam generation and condensate return systems.
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Chemical Synthesis: Level detection in reactors where exothermic reactions create high-temperature and high-pressure environments.
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Cryogenic Storage: Monitoring levels of liquefied gases or refrigerated chemicals at temperatures down to -60 °C.
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Safety-Instrumented Systems (SIS): Serving as a critical safety barrier in high-temperature processes that require SIL-rated instrumentation.




