Technical Characteristics and Chemical Resilience
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High-Performance Coatings: The FTL51C offers a range of coatings to match specific chemical challenges. Enamel provides excellent resistance against strong acids and oxidizers, while PFA (available in Rubyred or conductive versions) offers superior non-stick properties and broad chemical compatibility. ECTFE (Halar) is also available for specialized industrial requirements.
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Functional Safety (SIL2/SIL3): Developed according to IEC 61508, the FTL51C is certified for use in high-risk safety loops. The electronics continuously monitor the tuning fork frequency to ensure the sensor is intact and functional.
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Second Line of Defense: This device is equipped with a gas-tight feedthrough as an additional safety barrier. This prevents hazardous or corrosive process media from entering the electronics housing or escaping into the environment if the primary sensor diaphragm is compromised.
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Media-Independent Switching: The vibronic principle ensures the switching point remains accurate regardless of changes in density, conductivity, or viscosity. It is unaffected by the presence of air bubbles, foam, or turbulence within the vessel.
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Maintenance-Free Operation: With no mechanically moving parts, the FTL51C eliminates the risks of jamming or wear. The coatings also help reduce material build-up, ensuring the fork remains active and sensitive even in “sticky” media.
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Hygienic Options: For aggressive cleaning agents or specialized food/pharma processes, FDA-conform PFA coatings are available, ensuring compliance with sanitary requirements while maintaining chemical resistance.
Technical Specification Matrix
| Feature | Technical Details |
| Measuring Principle | Vibronic (Tuning Fork) |
| Coating Materials | ECTFE, PFA (Edlon, Rubyred, conductive), Enamel |
| Process Temperature | -50 to +150 °C (-58 to +302 °F) |
| Process Pressure | -1 to +40 bar (-14.5 to +580 psi) |
| Output Signal | FEL51 (AC), FEL52 (DC-PNP), FEL54 (Relay), FEL58 (NAMUR), PFM |
| Safety & Compliance | SIL2/SIL3, WHG, ATEX, IECEx, FDA (for PFA) |
Primary Applications
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Acid and Alkali Storage: Monitoring levels in tanks containing hydrochloric acid, sulfuric acid, or sodium hydroxide where metal sensors would corrode.
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Chemical Reactors: Reliable point level detection in aggressive reaction environments with varying concentrations and temperatures.
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Toxic Media Containment: Utilizing the second line of defense to provide an extra layer of protection when handling hazardous chemicals.
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Aggressive Cleaning Processes: Use in industrial CIP systems where high concentrations of cleaning agents are used at elevated temperatures.
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Safety Instrumented Systems (SIS): Serving as a high-level alarm in SIL-rated loops for environmentally sensitive or dangerous process liquids.
