Xtralis of Hemel Hempstead, United Kingdom, is offering a new generation of its ADPRO PRO external detectors. The highly sensitive, standalone passive infrared detectors detect human targets by sensing temperature differences between them and the background. Because the operation is passive, intruders cannot identify the area being protected. The new PRO 30 has a detection pattern of 30 by 20 meters, while the PRO 40 offers a 40- by 10-meter pattern and the PRO 50 has a detection pattern of 50 by 30 meters. The detectors trigger CCTV, pan-tilt-zoom, and dome cameras, in addition to video switchers and video transmission units. All models can adjust sensitivity to suit conditions, and adaptive threshold circuitry introduces an intuitive scene-learning capability to reduce false alarms. Detectors have weatherproof housings for reliable operation in harsh conditions.