The AP669 Ceiling Mount PIR with Dual Optic Technology incorporates two independent pyros, two separate ASICs and two 180° mirrors that provide two independent 180° fields of view. This design enables the detector to substantially increase the overall volume of its coverage area, providing superior detection performance and enhanced false alarm immunity. Combining 4D signal image processing with the dual mirror optical system, the AP669 analyzes the size, shape, duration and speed of incoming signals, and actually adapts the alarm threshold when faced with harsh environments. The two separate 180° mirror segments provide additional flexibility by enabling one of the 180° mirrors segments to be shunted. One half of the coverage pattern is eliminated simply by programming a dip switch located in the back of the sensors housing. Unlike other ceiling-mount PIRs, the AP669’s patented mirror optical system yields 18 solid curtains that cover the room with detection. The curtains emanate from the detector's ceiling-mount position to the floor below and out 30 feet in all directions for maximum coverage at all mounting heights up to 16 feet. The AP669’s rotating base allows installers to shift the entire protection pattern by 15° in either direction for easier aiming.