OPTISWITCH is a level sensor with tuning fork for level detection. It is designed for industrial use in all areas of process technology and is preferably used for bulk solids.
The vibrating element (tuning fork) is energized piezoelectrically and vibrates at its mechanical resonance frequency. The piezos are separated mechanically and are hence not subject to temperature shock limitations.When the vibrating element is immersed in the product, the vibrating frequency changes. This change is detected by the integrated oscillator and converted into a switching command.


  •  Highly robust tuning fork.
  •  Insensitive to build-up.
  •  Set-up without filling.
  •  Detection of solids in water.
  •  Maintenance-free.
Benefits Product Specifications Applications Technical Documentation
 Fault monitoring

The electronics of OPTISWITCH continuously monitors the following criteria:

•     correct vibrating frequency
•     line break to the piezo drive

If one of the listed faults is detected or in case of voltage loss, the electronics takes on a defined switching condition, i.e. the relay deenergizes (safe condition).

Solid detection in water

With the OPTISWITCH (3100 C, 3200 C, 3300 C) version for solid detection in water (option), the vibrating element is adjusted to the density of water. If submerged in water (density 1 g/cm³), OPTISWITCH signals "uncovered". Only if the vibrating element is also covered with solids (e.g. sand, sludge, etc.) will the sensor signal "covered".