In recent days, Western countries frequently witnessed various shootings, explosions, and other cases. In contrast, China's safe travel environment has been praised by more and more foreigners in China.

Our country attaches great importance to the safety of citizens’ travel. There are some common security detection devices around us, such as security doors, metal detectors, and X-ray scanners. Among them, the security door as a convenient and reliable security inspection equipment, made important contributions to people's travel security, whether it is the subway or the station or some stadium entrance can see it standing figure, today I will take you to find out about our common And strange security door.

      The security door is a detection device for detecting the presence or absence of carrying metal objects. It is also called a metal detection door. It is mainly used in airports, stations, large-scale meetings and other public places where people are relatively large. It is used to inspect metal objects hidden on the human body such as firearms. , control tools and so on. A few high-grade security doors on the market can be used when the inspected personnel pass through the security gate. When the metal carried by the person exceeds the preset parameter value according to the weight, quantity or shape, the security door immediately reports an alarm and displays an alarm. The place where the metal is located allows security personnel to discover in time the metal items that the person carries. The best security door can detect clip-size items.

      The reason why security gates can warn passing metal objects is due to the use of magnetic field sensing technology. There is a sensor behind the door panels on both sides that can sense the change of the electromagnetic field. When the metal is excited by the alternating electromagnetic field emitted by the sensor, an eddy current is generated internally, which generates a new magnetic field with a different direction from the original electromagnetic field. The sensor senses this change signal, and then undergoes amplification processing of the circuit, and the signal quantity reaches a preset value. When it is worth, an alert can be issued.

      Metal detector doors are widely used to protect our personal safety.