Infrared alarm points active and passive two. Active infrared alarm, the alarm unsolicited infrared, infrared encounter obstacles, it will bounce back and be received alarm probe. "Entrapment" in the infrared defense systems fall into this category. If the probe to monitor the infrared is stationary, which is issued with the red line and constantly bounce, then the alarm will not alarm. When there is an active object touched the root of an invisible line, when the probe will detect abnormalities, along with the police. Wuhan Star Popular Science Technology Co., Ltd. Main products include: science exhibits, teaching equipment, experimental box, Science and Technology Museum building, children's play equipment, laboratory construction, primary and secondary general education equipment, science museum exhibits, multimedia teaching vocational equipment, Warmly welcome all dealers or professional bodies to cooperate with our company, to develop the market and contribute to science and education.