Introduction
Model 420 Passive Infrared (PIR) Intrusion Sensor is an advanced stand-alone sensor designed for specialized outdoor intrusion detection applications. A four-zone, continuous and gap-free curtain sensing pattern detects intruders by sensing temperature (heat radiation) difference between the background scene and intruder. The pattern includes long, medium and short range detection segments, plus a controllable Creep Field that protects the area surrounding the mounting pole, which eliminates the detection ‘dead zone' characteristic of traditional PIR sensors.
Minimal clear zone requirements for the Model 420's detection pattern make this sensor ideal for intrusion detection in very narrow corridors.
The latest detector and signal processing technology, plus precision mirror optics, allow Model 420 to operate in broad-ranging environments. Double optical filtering, Digital Signal Processing (DSP), Signal Shape Analysis (SSA), and Adaptive Threshold Decoding (ATD) ensure reliable operation under changing climatic conditions. Nuisance alarms from rain, snow, wind, and fog are virtually eliminated.
Model 420 electronics and optics are housed in a rugged IP65 heavy-duty plastic enclosure. An internally regulated heater connected to sensor electronics and operating from the supply voltage prevents the unit's optical surface from fogging or frosting in cold weather. A universal mounting bracket allows mounting to flat surfaces or 100 mm (4 in) O.D. posts.
User-friendly installation software with flexible controls simplifies alignment, signal check and routine maintenance. Set-up is easily accomplished by aiming the sensor slightly downward into the area being protected, applying power and allowing the sensor to establish a reference level for operation. A walk test and final sensitivity adjustment optimizes detection.
Key Feature
* Detection to 122 m
* Well-defined, narrow field-of-view
* Double optical filtering blocks unwanted radiation from sunlight and other high intensity light sources
* Gap-free coverage: no finger-and-gap coverage patterns
* Anti-vandal function signals an alarm if sensor alignment is altered
* Adaptive threshold decoding
