Vital is a compact level limit switch suitable for all kinds of free flowing solids and grains for overspilling and dry run detection. Vital is unaffected by spurious vibrations and is independent of the application material’s electrical properties. Vital can be made with a minimum of 1 1/4″ mounting and 100 mm tines.
Principle
A tuning fork made of stainless steel is kept vibrating at its resonant frequency by piezo ceramic elements. When the service material covers the tines of the fork, vibrations are damped. This damping is sensed electronically and the processed signal is used to energize a relay whose contacts in turn are used for annunciation and / or control.