The Banner QS30H2O series water sensor was developed to detect the presence of water. Its electro-optical components are tuned to one absorption band of water in the long infrared spectrum. The emitted infrared light penetrates many types of plastic and glass containers, but will not pass through water-based fluids, nor through opaque substances such as wood, metal or cardboard. Accessory apertures are available to attenuate or shape the beam for low-gain applications, for example, clear water in a clear bottle.

Low-gain models are recommended for sensing applications where the liquid container is transparent or when the thickness of liquid being detected is small. Some examples are clear glass test tubes and clear PET beverage bottles. High-gain models are recommended when the liquid container is light-blocking (translucent) and when the thickness of liquid being detected is large. Some examples are HDPE milk containers, colored PET beverage bottles, and etched glass containers.

For all applications, the sensors must be installed to maximize the optical contrast between the clear and blocked states. The installer can use apertures and mechanical alignment of the sensors to achieve the best results. The Banner QS30H2O sensor enhances the available contrast by taking advantage of the absorption band of water.

Each discrete output model has two bipolar outputs that switch simultaneously: one each NPN (sinking) and PNP (sourcing). Light Operate and Dark Operate models are available. The versatile housing provides multiple mounting configurations in a minimum of space. These sensors are extremely rugged, powerful and leakproof, with epoxy-encapsulated electronics for maximum resistance to mechanical shock and vibration. They are powerful enough to burn through dust and many types of industrial and process contamination.