Electromechanical Level Measurement

Electromechanical Level Measurement

Electromechanical level measurement is a “sounding” method primarily used for continuous level measurement in bulk solids. It is well known for dependable performance in very dusty environments and for installations where non-contact or dielectric-dependent technologies may struggle with heavy dust clouds, irregular surfaces, or challenging silo geometry. The approach is especially common in tall silos and bins handling powders, granulates, and coarse solids.

The measuring principle uses a sensing weight lowered on a tape or cable into the vessel. When the weight reaches the product surface, a change in tensile force is detected; the drive reverses and rewinds while the system counts motion to determine distance traveled. With vessel height known, the measured distance converts to level. Modern systems incorporate safeguards to prevent the weight from running into outlets or conveying equipment by using fail-safe control logic.

Benefits include insensitivity to dielectric constant and many surface effects that complicate other continuous methods in solids. Because the measurement is physical and distance-based, it can be reliable even where dust, filling noise, or material properties vary. Cost-effectiveness is often favorable for bulk solids applications, particularly when the measurement can be periodic or cycled rather than requiring rapid, high-frequency tracking.

Typical applications include silos containing cereals and grain products, plastic pellets and granulate, powdered chemicals, and similar bulk solids. It is also applied where inventory visibility is required in high bins, railcar loading silos, or storage structures that experience frequent dust generation during filling and discharge.

Engineering considerations include cycle timing (continuous vs. interval measurement), mechanical wear of the tape/cable and drive components, and clearance to avoid internal obstructions. Material behavior matters: severe bridging, heavy crusting, or highly adhesive solids can influence the “surface detect” event and may require placement away from common hang-up zones. Dust explosion protection, sealing strategy, and maintenance access should be incorporated into the installation plan.

Forberg Smith, an exclusive authorized representative of sales and service for Endress+Hauser.