Photoelectric Liquid Level Sensor, PNP/ NPN

A photoelectric liquid level sensor uses changes in the refraction and reflection of infrared light to determine the liquid level. When the probe tip is immersed in the liquid, the refractive index changes, the light intensity at the receiving end decreases, and thus an output liquid level signal is generated. It has a simple structure, fast response speed, and high reliability.

It can typically detect transparent or semi-transparent liquids such as water, oil, alcohol, coolant, and antifreeze. Some models can also detect opaque liquids, but this requires a specially designed probe. Before use, it is best to confirm that the refractive index, temperature, and corrosiveness of the medium meet the requirements.

It depends on the material. Commonly used materials include PPS, PC, PEI, and 304/316 stainless steel. If the medium is highly corrosive, such as acid, alkali, or solvent, an appropriate material or a specially designed probe should be selected. The composition and concentration of the medium must be provided for matching when selecting a model.