The SDX optical level switches uses the principle of light reflection in a prism to sense the absence or presence of a liquid at the point where the sensor is installed in a tank, pipeline or other type of container.

The SDX optical level switches emit a beam of infrared light into the tip (prism) of the sensor. In the absence of the liquid at the sensor tip the light is reflected back to the sensor’s receiver. When the target liquid is present surrounding the sensor tip, the light is refracted into the liquid and away from the SD series level switch receiving component thus how liquid presence and absence is determined. The SD series output will be activated accordingly. These optical level switch devices are compact, cost-effective and ideal for a wide variety of fluids.