The anti-theft alarm system uses physical methods or electronic technology to automatically detect the intrusion that occurs in the deployment monitoring area, generate an alarm signal, and prompt the on-duty personnel to place an alarm in the area where the countermeasures may be taken.
Anti-theft alarm is an electronic device that generates alarm function through physical method or electronic technology. It is mainly composed of anti-theft alarm host and anti-theft alarm accessories. Usually in the process of use, the anti-theft alarm accessories detect the intrusion occurred in the deployment of the monitoring area, or actively triggered by the accessories, generate an alarm signal, the alarm signal is transmitted to the alarm host, the alarm host issued an alarm.
Anti-theft alarm alarm is generally divided into two types: one is the scene alarm sounded, the other is through the network or communication methods to send alarm information to the designated person or system platform.
There are mainly several reasons for false positives and false negatives in the alarm system. The wireless detector's anti-jamming capability shows that the same-frequency interference is likely to cause false positives and false negatives. Infrared detectors are inaccurate in judgment of intrusion behavior and cause false reports. Infrared detectors are susceptible to false alarms due to environmental factors such as temperature and light. The power supply system of the wireless detector lacks power. When the power is low, there is no effective information transmission so that the detection distance of the detector becomes shorter or it does not work, resulting in missed false alarms. Because the host and the detector are all set by wireless encoding, there is repetition and the host and detector re-encoding result in false alarms.
1 false alarm system caused by improper device selection is the key to system design, and a wide range of alarm equipment, but also have their own characteristics, scope of application and limitations, improper selection will cause false alarm. For example, the use of seismic detectors near the near-earth source (airfield and railroad side) can easily cause false alarms in the system. The use of ultrasonic detectors in places where bats are frequent can also cause false alarms. This is because bats emit ultrasonic waves. High-frequency sounds such as electric bell and metal impact can cause false alarms for single-technology glass break detectors. Therefore, to reduce false alarms caused by improper equipment selection, system designers must be familiar with various alarm devices. The principle, characteristics, application scope and limitations. At the same time, we must also grasp the on-site environmental conditions, climate conditions, electromagnetic field strength, and changes in illuminance in order to select alarm equipment according to local conditions.
In addition to the selection of equipment and equipment, the improper design of the system also manifests itself in the equipment installation location, installation angle, protective measures, and system wiring. For example, when a passive infrared intrusion detector is installed facing an air conditioner and ventilation fan, it will cause a false alarm of the system; if an active outdoor infrared detector is not used for proper sun protection (the sun shield is also best for protection), it is bound to Caused by the system of false alarms; alarm lines and power lines, lighting lines and other strong electric circuit spacing is less than 1.5m, without the protection against electromagnetic interference, the system will also generate false alarms.
2 Misuse caused by improper construction
This part of the problem is mainly manifested in the following aspects:
(1) No strict construction according to design requirements. (2) Improperly installed equipment or improper inclination. (3) Solder joints have vacant welds, burrs, or shielding measures. (4) The sensitivity of the device is poorly adjusted. (5) Inspection equipment for construction does not meet the measurement requirements. The solution to the above problems is to strengthen the supervision and management of the construction process and implement the safety supervision system as soon as possible. This will help improve the quality of the project and reduce the number of false alarms due to construction.
3 Misuse caused by improper use of the user
Improper user use often causes false alarms in the alarm system. For example, the window with a magnetic switch was not inserted, and it was blown away by night; the staff strayed into the warning area; the emergency alarm device was accidentally triggered; the system check-in personnel operated erroneously; The cause of the system's false alarm. To analyze the user's improper use, find out where the error is, and improve the user's level, can greatly reduce the number of false alarms in the alarm system.
4 false alarm caused by environmental noise
The false alarm caused by the environmental nuisance refers to the alarm system being generated under normal working conditions. It is unavoidable from the principle, but the facts are not needed and it belongs to false alarm. For example, thermal airflow causes false alarms from passive infrared intrusion detectors; high-frequency sounds cause false alarms from single-technology glass break detectors; and ultrasonic sources cause false alarms from ultrasonic detectors. The most effective measure to reduce such false alarms is to use dual-mode detectors (two different principle detectors detect the 'target' at the same time, and the alarm only sends an alarm signal). The current products include: microwave-passive infrared double detector, voice-activated glass broken double detector, ultrasonic-passive infrared double detector and so on. However, some environmental noise detectors can't do anything, such as: rats infestation areas; pets walking in the room and so on. To this end, scientific and technical personnel have introduced micro-processing technology into the alarm system so that they have a certain ability to identify and think, and can judge to some extent whether it is an intruder or an alarm caused by environmental noise.
Therefore, to reduce false alarms, it is indispensable to proceed from the aspect of air defense. The establishment of alarm information confirmation mechanism can reduce the number of alarms. After the alarm center receives the alarm information, it shall send a confirmation signal to the alarm host to indicate that the center has received it, and the alarm host shall retransmit if it does not receive the confirmation signal. In terms of technology, alarm signals are confirmed by various means. For example, multiple detectors (commonly used by dual infrared + infrared plus microwave) are installed, and alarm signals are sent to the host when multiple probes detect an intruder signal at the same time. , thereby reducing the false positive rate.
In addition, the state may also formulate some laws and regulations concerning false alarms. For example, some local government agencies in foreign countries may take measures such as inspections, fines, and penalties against alarm users or security companies. If the number of alarms exceeds the specified number within a certain period, fines will be imposed. This can play a role in restricting human error.
Casual Shoes For Men,Mens Casual Dress Shoes,Mens Black Casual Shoes,Mens Brown Casual Shoes
Shangqiu JIAYING SHOES CO.,LTD. , https://www.jysportshoes.com