The Isocom Components 2004 LTD H21A3 Optical Sensor is a slot type photointerrupter with a transistor output and PC pin. The device is designed to detect the presence of an object in a sensing area using an infrared light source and an infrared detector. It is ideal for applications requiring a small and precise optical sensing solution. The H21A3 features a wide viewing angle, low power consumption, and a fast response time. The sensor is capable of detecting changes in light intensity as small as 40µW/cm2. It features a high noise immunity and is RoHS compliant. The device is enclosed in a small package and is easy to mount making it perfect for small and space-constrained applications.