What is Displacer Level Switch?

Basically the displacer level switch works on the principle of shifting weight. A displacer is used, which is a kind of very heavy float, which is suspended by a spring. When the media level touches the displacer and submerges it in the water, due to the buoyant force, the weight of the displacer decreases compared to the acting medium. This releases spring pressure and changes electrical output. This means that the weight of the displacer must be greater than the weight of the media in normal conditions (when the media is not touching). Only then, it will detect the weight change.