Technical Characteristics and Operational Safety
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Mechanical Reliability: The FMM20 uses a tried-and-tested electromechanical principle that remains unaffected by the dielectric constant of the material, dust clouds, or vapor, making it a “go-to” solution when radar or ultrasonic sensors face challenges.
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Advanced Fail-Safe Control: It features a fully electronic digital minimum fail-safe control. This critical safety feature prevents the sensor weight from accidentally running down into the silo outlet, protecting downstream conveying systems from damage.
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User-Friendly Interface: Commissioning is simplified through a menu-guided local operation using a clear, 4-line text display. This allows for quick setup of measuring intervals and silo height parameters.
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Versatile Power Options: The device is equipped with a wide-range power unit (90 to 253VAC) or a 24VDC version, ensuring compatibility with various industrial electrical infrastructures.
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High Dust Tolerance: Because the measurement is mechanical, the FMM20 provides safe and accurate readings even in environments with extreme dust concentrations where non-contact sensors might suffer from signal attenuation.
Technical Specification Matrix
| Feature | Technical Details |
| Measuring Principle | Electromechanical (Weight and Cable) |
| Application | Light bulk solids (wheat, plastic, powder), liquids |
| Measuring Range | Up to 32 m (105 ft) |
| Process Temperature | -20 to +150 °C (-4 to +302 °F) |
| Process Pressure | 0.8 to 1.1 bar (11.6 to 15.9 psi) |
| Accuracy | ±1 pulse (approx. ±5 cm or ±2″) |
| Output | 0/4-20mA, Relay (Counting pulses / Active) |
Primary Applications
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Agricultural Silos: Accurate level monitoring of wheat, corn, and other cereals where dust is constantly present during filling.
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Plastic Processing: Measuring plastic granulates and resin powders in storage bunkers.
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Powder Storage: Ideal for fine-grain powders in the chemical or food industry that tend to create heavy dust blankets.
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Construction Materials: Monitoring sand or dry mortar levels in medium-sized silos.
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Liquid Tanks: Can be used in liquid tanks where surface foam or heavy vapor prevents the use of ultrasonic or radar technology.
