Plastic Fresnel Lens S9008 used in Alarm System

The fresnel lens is a optical element, one side is smooth, another side is by a ring a part of concentric garden composition. Fresnel lens arrays designed for Passive Infrared Sensor. The optical surface increases lens sensitivity for PIR sensor application. All the PIR sensor must work with the Fresnel Lens.

The Fresnel lens, simply say to be in the lens side have equi-distant tooth tattoo. Through these tooth tattoo, can achieve to specified spectrum light band tong (reflecting or refraction) role. The traditional grinding optical equipment band-pass optical filters are expensive. The Fresnel lens can greatly reduce costs. A typical example is PIR (passive infrared detector). PIR used widely in alarm.