Passive Infrared Sensor 07
Passive Infrared Sensor 07 : PIR-Based Motion Detector: (4) Focusing: Different mechanisms can be used to focus the distant infrared energy onto the sensor surface. (4. 1) Lenses: The plastic window covering may have multiple facets molded into it, to focus the infrared energy onto the sensor. Each individual facet is a Fresnel lens. Multi-Fresnel lens type of PIR: PIR motion detector housing with cylindrical faceted window. The animation highlights individual facets, each of which is a Fresnel lens, focusing light on the sensor element underneath. PIR front cover only (electronics removed), with point light source behind, to show individual lenses. PIR with front cover removed, showing location of pyroelectric sensor (green arrow). (4. 2) Mirrors: Some PIRs are manufactured with internal, segmented parabolic mirrors to focus the infrared energy. Where mirrors are used, the plastic window cover generally has no Fresnel lenses molded into it
No records Found