False alarm refers to the actual situation does not require the alarm and the system sent the alarm signal, which does not include the alarm signal caused by those due to harsh natural climate and other alarm companies and users can not manipulate the special environment. According to this definition, the United States UL standards:" Each alarm system can only have four false alarms per year.
False alarm caused by alarm device malfunction
False alarm caused by Alarm system design, improper construction caused
False alarm caused by Improper system design
False alarm caused by Improper construction
This part of the problem mainly in the following areas:
(1) not strictly in accordance with the design requirements of construction.
(2) The equipment is not installed properly or the inclination is not suitable.
(3) solder joints are Weld, burr, or shielding measures should not be.
(4) Poor sensitivity adjustment of the equipment.
(5) construction testing equipment does not meet the measurement requirements.
False alarm caused by environmental interference
The more effective measures to reduce such false alarms are the use of dual-detector (two different principles of the detector at the same time to detect the "target", then the alarm issue an alarm signal). The current products are: microwave - passive infrared dual detectors, voice - vibration glass broken double detector, ultrasonic - passive infrared dual detectors and so on. But some of the environmental interference dual-detector can do nothing, such as: mice usually haunt in the prevention area ; pets in the living room and so on. So now, the scientific and technical personnel will introduce micro-processing technology alarm system, so that it has a certain ability to identify and analyze. To certain extent, can judge whether the alarm caused by the intruder or environmental interference .