Vibronic Point Level Detection

Vibronic Point Level Detection

Vibronic point level detection is a robust switching technology used for overfill prevention and point level control in both liquids and bulk solids. It is positioned as highly reliable across changing process conditions and is described as unaffected by factors such as changing media properties, turbulence, foam, vibration, or build-up. The category includes tuning-fork style sensors for liquids (Liquiphant) and rod-style sensors for solids (Soliphant), supporting a wide range of industries and applications.

The measuring principle is based on resonance behavior. For liquids, a tuning fork is excited at its resonant frequency using a piezoelectric drive; when the fork is covered by liquid, the oscillation frequency changes and the instrument converts that change into a switching signal. For solids, a one-rod sensor is excited similarly; as material covers the sensor, the oscillation amplitude changes and is analyzed to produce the switch output. This resonance-based detection provides a clear covered/uncovered indication without relying on conductivity or dielectric thresholds.

Benefits include broad media independence, simple installation, and readiness for use without calibration in typical point level roles. The category is also described as self-monitoring, maintenance-free, and without wear and tear - an advantage where frequent cleaning or mechanical servicing would be costly. Vibronic devices are highlighted as suitable for functional safety applications (SIL 2/3) and as a “second line of defense” for overfill prevention, supporting high availability and safety strategies.

Typical applications range from basic minimum/maximum level control to certified leakage monitoring and overfill prevention, including duties tied to protective equipment and safety-rated plant sections. In solids service, vibronic switches are applied in fine-grained or powdery materials and can be used in hazardous areas with appropriate device selection. Common use cases include overfill alarms in storage silos, low-level detection for feeder protection, and reliable switching in processes where foam or turbulence would compromise float or conductive solutions.

Implementation considerations include selecting the correct sensor form factor (fork vs. rod), process connection, and insertion length to ensure the switch point represents the desired control/alarm condition. Mounting should avoid direct mechanical impact and excessive buildup zones when possible, even though the method is designed to tolerate many challenging effects. For safety functions, proof-test intervals, diagnostic coverage expectations, and fail-safe output behavior should be aligned with the overall safety lifecycle and site standards.

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