Technical Characteristics and Safety Excellence
-
Functional Safety (SIL2/SIL3): Developed according to IEC 61508 and IEC 61511-1, the FTL51 is suitable for use in high-integrity safety instrumented systems. It provides the necessary reliability for critical safety loops.
-
Second Line of Defense: The device features a gas-tight feedthrough between the process and the electronics compartment. This “second line of defense” ensures that even if the sensor diaphragm is breached by aggressive media, the process remains contained, protecting both the environment and the electronics.
-
Media-Independent Reliability: The tuning fork principle is immune to changes in density, conductivity, or dielectric constant. It reliably detects the liquid level even in the presence of heavy foam, air bubbles, or significant build-up on the fork.
-
Continuous Self-Monitoring: The FTL51 actively monitors the tuning fork for mechanical damage or heavy corrosion. If the resonance frequency shifts outside of expected parameters, the device triggers a fault signal, ensuring the safety function is always guaranteed.
-
High-Pressure Resistance: With the ability to withstand process pressures up to 100 bar, the FTL51 is suitable for demanding reactor vessels and high-pressure storage tanks.
-
Alloy Material Options: For highly corrosive environments where 316L stainless steel is insufficient, the sensor is available in high-performance alloys to ensure maximum durability and chemical resistance.
Technical Specification Matrix
| Feature | Technical Details |
| Measuring Principle | Vibronic (Tuning Fork) |
| Device Design | Extension tube version |
| Process Temperature | -50 to +150 °C (-58 to +302 °F) |
| Process Pressure | -1 to +100 bar (-14.5 to +1,450 psi) |
| Sensor Material | 316L Stainless Steel, Alloy (e.g., C22) |
| Output Signal | FEL51 (AC), FEL52 (DC-PNP), FEL54 (Relay), FEL58 (NAMUR), PFM |
| Safety & Compliance | SIL2/SIL3, WHG, ATEX, IECEx, FM, CSA |
Primary Applications
-
High-Level Overfill Protection: Serving as the primary or secondary safety alarm in chemical, oil, and gas storage tanks to prevent environmental spills.
-
Pump Dry-Run Protection: Safeguarding expensive pumps by detecting the absence of liquid in suction lines, even with aerated or viscous fluids.
-
Hazardous Area Monitoring: Certified for use in Zone 0, 1, and 2 environments where explosive gases or vapors are present.
-
Corrosive Media Handling: Utilizing Alloy sensor materials for point level detection in aggressive acids or alkalis.
-
Safety Instrumented Systems (SIS): Integration into safety loops where a high Safety Integrity Level (SIL) is required by international standards.
