How to identify supermarket burglar antenna
August 29, 2023
At present, there are many EAS brands in China, and the quality is quite different. The price is mixed. In fact, there are not many real production and R&D capabilities. What is a cost-effective burglar antenna? Generally can be distinguished from the following aspects.
Effective detection rate:
It can be called a blind spot, which can also be called a missed report rate. Whether it is domestic or imported, there will be blind spots due to the influence of the environment. The blind zone refers to the area called the blind zone when the effective tag passes through any detection area of the anti-theft antenna and the alarm signal cannot be detected by the anti-theft antenna. The blind area can be affected by environmental interference, installation distance, etc. In the ideal electromagnetic field environment, the general installation distance is 90CM, the detection label is a domestic 4*4CM soft label, except that there is a certain blind area in the middle of the anti-theft antenna in the horizontal direction. There is no blind spot in any direction. The blind spot in the horizontal direction is not terrible. Who can guarantee that the goods that are taken out are kept at a “level”? As long as there is a slight inclination, the anti-theft antenna will send out an alarm. Who has the level to try this "level"?
False alarm rate:
The false alarm rate is a measure of the main performance indicators of anti-theft antennas. False positives are inevitable in RF systems. A blind spot that is too large can only lose a small amount of individual goods, but too many false positives can cause a lot of trouble between the mall and the customer. False alarm refers to false alarms that are triggered when no anti-theft tag passes through the detection area of the anti-theft antenna. Of course, such explanation is too narrow. However, there are many reasons for causing false alarms in practical applications. Some reasons are not clear at all because radio signals cannot be seen or touched without an instrument, and false alarms have no regularity. Secondly, the cause of false positives is mostly determined by the performance of the machine. Traditional methods using analog signals have lower anti-jamming capability and can easily cause false positives. It is even better to use a single-chip chip to process signals, except for similar labels. In addition to the signals, basically a false alarm can be caused; and with a DSP digital signal processing system, the false alarm rate is even lower. In any case, the anti-theft antenna for analog signals has also been used for more than ten years in China. There are still simulators on the market for sale, and at least 40% of simulators are on the market. However, the majority of the general site environment is still ideal, can be installed normally, even if there is a phenomenon of false positives, as long as we handle properly, it can still play a good anti-theft effect.
