Technical Characteristics and Silo Integration
-
Vibronic Measurement Principle: The tuning fork is piezo-electrically excited to its resonance frequency. When covered by bulk solids, the vibration frequency is dampened; the electronics detect this shift and trigger a switching signal. This method is highly reliable for non-fluidized solids and is completely unaffected by flow noises or external vessel vibrations.
-
Rigid Extension Pipe: Available in three standard lengths, the extension pipe allows for precise positioning of the detection point. This is particularly useful for top-entry installations where the material surface is not immediately adjacent to the silo roof.
-
Maintenance-Free Durability: With no mechanically moving parts, the FTM21 eliminates the jamming and wear issues common with rotary paddle switches. The 316L stainless steel fork is highly abrasion-resistant, ensuring a long service life even when monitoring building materials like cement or lime.
-
Plug and Play Simplicity: No calibration or on-site media adjustment is required. The device is ready for operation immediately after installation, reducing commissioning time and costs.
-
Status Monitoring: The device is available with a transparent plastic housing cover, allowing operators to verify the switching status via an internal LED without opening the enclosure. A robust aluminum housing is also available for more demanding environments.
Technical Specification Matrix
| Feature | Technical Details |
| Measuring Principle | Vibronic (Tuning Fork for Solids) |
| Device Design | Extension pipe version (500 mm, 1,000 mm, 1,500 mm) |
| Process Temperature | -40 to +150 °C (-40 to +300 °F) |
| Process Pressure | -1 to +25 bar (-14.5 to +360 psi) |
| Sensor Material | 316L Stainless Steel |
| Housing Material | Plastic (PBT) or Aluminum |
| Output Signal | DC-PNP, 2-wire AC, Relay |
| Safety & Compliance | ATEX, IECEx, CSA (Dust/Gas ignition protection) |
Primary Applications
-
Building Materials: Monitoring sand, gravel, and cement in storage silos where top-entry detection is required.
-
Food and Grain: High-level detection in storage bins for wheat, corn, animal feed, or flour.
-
Plastics and Chemicals: Point level switching for plastic pellets, granules, or powdered chemical additives.
-
Wood Processing: Level monitoring for wood chips, pellets, or sawdust in collection hoppers.
-
Dust-Hazardous Environments: Fully certified for use in areas where combustible dusts (Zone 20/21/22) are present.
