DFS-IR1907 optical level sensor is as all know as photoelectric level sensor, infrared liquid level switch and etc. The theory is infrared, when DFS-IR1907 detects water or other liquid, it outputs a low voltage signal; when it detect air, the output signal is high voltage value. DFS-IR1907 is a noon-contact type sensor, the size is small, the structure is simple. Compared with magnetic float switch, there is not a stuck issue. The installation way is fixable, such as placed up or down, sideways or diagonally mounted, multi-direction installation. The level sensor has long using life, it has more than 50,000h life time.