What is an optical level switch?

Optical level switches are basically similar to radar sensors; The difference is that instead of waves, optical light is emitted. Light is transmitted and returned in a cone-shaped prism structure. This means that the light will not travel all the way to the medium, but will be confined within a structure. When there is no medium in this structure, the light will reflect back. If there is a medium present then the light will not be reflected back. This causes the electrical output to change.