Principle of anti-theft alarm to reduce false alarms

The anti-theft alarm is an alarm instrument that uses modern science and technology to prevent crime and detect criminal activities in time. There are many types, from the working principle can be divided into switch alarm, sound alarm, sensor alarm, infrared alarm, laser alarm and so on. With the development of television technology and electronic computer technology, advanced monitoring, control and alarm systems using televisions and computers have emerged. There are two ways to transmit the alarm signal: wireless and wired. With the strengthening of crime prevention work. The anti-theft alarm has played an obvious role.

The anti-theft alarm system uses physical methods or electronic technology to automatically detect intrusions that occur in the defense monitoring area, generate an alarm signal, and remind the duty personnel of the area where the alarm has occurred, and display the system that may take countermeasures.

Principle of reducing false alarms

The current false alarms and omissions in the alarm system are mainly due to the following reasons. The anti-jamming capability of wireless detectors shows that the same frequency interference can easily cause false alarms and false alarms. Infrared detectors are not accurate enough to judge intrusions, causing false alarms and false alarms. Infrared detectors are susceptible to temperature, light and other environmental factors to produce false alarms. The power supply system of the wireless detector lacks power, and the information is not effectively transmitted when the power is low, so that the detection range of the detector becomes shorter or does not work, resulting in false alarms. Because both the host and the detector use the wireless encoding method to set the repeated code, the host and the detector re-code and cause false alarms.

Let's analyze the main reasons for the infrared detection alarm that will cause false alarms and omissions. The current false alarms and omissions in the alarm system are mainly due to the following reasons. The anti-interference ability of wireless detectors is manifested as co-channel interference is easy to cause false alarms and false alarms. Infrared detectors are not accurate enough to judge intrusions, causing false alarms and false negatives. Infrared detectors are susceptible to temperature, light and other environmental factors to produce false alarms. The power supply system of the wireless detector is short of power, and the information is not effectively transmitted when the power is low, which makes the detection range of the detector shorter or does not work, resulting in false alarms and false alarms. Because both the host and the detector adopt the wireless encoding method to set up the code, the repeated codes cause the host and the detector to re-code and cause false alarms. The quality of some alarms is too ashamed to cause false alarms due to component damage and poor production technology. It is also related to the selected equipment, installation method, angle, and location. For example, the selected detector is a vibration detector installed in Places with relatively large seismic sources (such as airports, railways, etc.) will cause false alarms when planes and trains are in motion. If bats often appear in places where ultrasonic detectors are used, false alarms may be easily caused, which may be affected by the environment For example, air movement, pet actions, etc., there are also human factors such as improper operation by the user, accidental triggering of the alarm, mistaken entry, mistaken entry into the fortified visit area, etc., which will cause false alarms. The reasons for false positives and under-reports are many and complex. Therefore, to reduce the false alarms and false negatives of anti-theft alarms, the most important thing is to consider various factors, such as the selection of detectors from technology and performance, including the selection of sensor probes, and the shape design of Fresnel lenses. Microprocessor program, multi-identification technology, automatic code hopping rolling coding technology, production technology, usage method, temperature compensation, sensitivity detection distance adjustment, etc. These comprehensive factors all determine the performance and false alarm rate of the detector.