The optical level switches of this series are ideal for the detection of fluids with low DK value, such as lubrication oil or hydrocarbons. Optical level sensors detect the change of the refractive index at medium contact with the transparent tip from polyethersulphone (PES) or glass. The sensors with stainless steel housing and glass tip are also suited for the detection of aggressive media, such as solvents. Also available with Ex certification according to ATEX and IECEx.