Technical Characteristics and Rope Versatility
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Flexible Extension Rope: The FTM52 utilizes a high-strength extension rope available in lengths from 750 mm to 20,000 mm. This flexibility allows the sensor to be suspended from the top of the silo to monitor levels deep within the vessel, providing a reliable switching point that is immune to the mechanical stresses that might bend a rigid pipe.
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Vibronic Measuring Principle: The tuning fork is piezo-electrically driven to its resonance frequency. When covered by solid material, the vibration is dampened. The electronics detect this change and trigger the switching signal. This method is exceptionally reliable for materials with low bulk density (≥ 10 g/l).
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Maintenance-Free Operation: With no mechanically moving parts, the FTM52 eliminates the wear-and-tear issues common with rotary paddle switches. It is unaffected by external vibrations from silo discharge aids or heavy material build-up on the fork itself.
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Advanced Diagnostics: The device features selectable monitoring for build-up and abrasion. It can actively detect if the sensor is being worn down by abrasive powders or if excessive build-up is occurring, allowing for predictive maintenance before a failure occurs.
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Safety and Integration: Developed according to IEC 61508, it is SIL2-rated for use in safety-instrumented systems. It offers a variety of electronic inserts (NAMUR, relay, PNP, PFM) to ensure seamless integration into existing control architectures.
Technical Specification Matrix
| Feature | Technical Details |
| Measuring Principle | Vibronic (Tuning Fork for Solids) |
| Device Design | Extension rope version (up to 20 m / 66 ft) |
| Process Temperature | -40 to +80 °C (-40 to +170 °F) |
| Process Pressure | -1 to +2 bar (-14.5 to +30 psi) |
| Sensor Material | 316L (optional PTFE coating) |
| Surface Roughness | 3.2 µm or 0.8 µm (polished) |
| Output Signal | Relay, PNP, NAMUR, PFM, Thyristor |
| Safety & Compliance | SIL2, ATEX, IECEx, FM, CSA |
Primary Applications
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Massive Flour and Grain Silos: Providing low-level alarms in storage structures reaching 20 meters in height.
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Powdered Animal Feed: Monitoring demand levels in large-scale mixing and distribution bins.
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Chemical and Plastic Granules: Reliable point level switching for plastic powders or fine chemical additives in tall vessels.
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Dye and Pigment Silos: Using the polished or coated fork options to prevent material sticking and ensure clean switching.
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Dust Hazardous Environments: Fully certified for use in areas where combustible dusts (Zone 20/21/22) are present.
