Photo Interrupter are the optical sensors that are equipped with light emitting and receiving elements that are aligned facing each other inside a single package. These equipments works by detecting the light blockage when a target objects comes in the vicinity of both the elements. They acts as an optical switch that do not make any contact with the objects. Photo Interrupter improves the reliability by preventing wear and tear due to abrasion. The detector part are protected with shield to ensure that they detects beam from the coupled source. They can be used for many applications which includes limit switches, pellet dispensing, general object detection, etc.