When we take a bus to a subway station or a train station, we must pass through the security gate. Many people do not understand metal security gates very much, and they will also be curious about what substances can be detected by security gates; in fact, security gates can detect all prohibited items in our luggage packages, but some medicines cannot be accurately detected.

　　The security door is actually a metal detector, which uses the principle of electromagnetic induction: the coil through which alternating current passes generates a rapidly changing magnetic field, which generates eddy currents in metal objects; makes a sound. The accuracy and reliability of the metal detector depends on the stability of the electromagnetic radiation frequency, which generally uses an operating frequency of 80 kHz. The lower the working frequency, the better the detection performance of iron. The higher the working frequency, the better the detection performance of high carbon steel.

The general train station is to prevent dangerous goods such as knives and guns from entering or getting on the train. Such as metal belts, keys, mobile phones, etc., basically can check the results, including thin silver foil, these metals have no "leakage network."

If the passenger passes through the security gate of the train station, the security gate can detect what prohibited items at this time: such as knives, but according to regulations, it is prohibited to carry household knives such as vegetable knives, large scissors, large fruit knives, razors, etc., but passengers can be checked as luggage . The above provisions also apply to carving knives, spears, swords, knots, etc., as well as axes, chisels, hammers, cones, heavy or spiked canes, and iron-headed climbing rods. Passengers who carry the above-mentioned items in emergencies without knowing it can put them in the tool disposal box set up by the security inspection department, or request security personnel to go through temporary storage procedures.

Many people will ask, can metal detection security doors detect drugs and explosives carried by human bodies? In fact, neither domestic nor imported metal detection security doors can detect whether human bodies carry drugs or explosives and other prohibited items. Because the principle of the metal detection door is to detect the metal cutting magnetic force line through the magnetic field induction. Prohibited items such as drugs and explosives do not have metal components and do not meet the detection conditions of metal detection and security gates, so it is impossible to detect using metal security gates.

Frankly speaking, the metal detection security door only detects metal, as long as the sensitivity of the security door is high enough, ordinary metals can be detected. The detection sensitivity depends on the application. Of course, the higher the sensitivity, the higher the price. Choose the metal detection security door or according to your needs, what kind of metal needs to be detected, how big is the metal detected, not only depends on the sensitivity, but also choose the powerful x-ray security machine manufacturers.