When material touches the fork tines, it effectively damps the mechanical vibrations. This-way material de-tunes the tuning fork off its resonance. This lack of resonance causes fall of amplitude as seen by electronics inside the LSV level limit switch. Which then generates presence of material signal at its output.

When material touches the fork tines, it effectively damps the mechanical vibrations. This-way material de-tunes the tuning fork off its resonance. This lack of resonance causes fall of amplitude as seen by electronics inside the LSV level limit switch. Which then generates presence of material signal at its output.