What happened when you went through security?
When you walk into the subway station with a bag and water on your back, you will be asked by the staff to put the bag on a conveyor belt of the detector, and when you pass through "a door", and the security inspector will hold a black Your "longboard" is waving on you while taking your water bottle to a machine for inspection. After completing these operations, even if you pass the security check smoothly, you can take the subway normally.
In the eyes of many people, these security inspection procedures have become a normal thing in life. Whether it is taking a plane, a high-speed train, a car, a subway, or visiting a museum, entering a convention and exhibition center, a performance venue, etc., you need to go through a "security inspection." "This off. So, do you know what happens every time you go through security?
As the name implies, "security inspection" is an inspection method adopted to reduce safety risks. By inspecting your luggage, goods, personal belongings, etc., you can prevent guns, explosives, controlled knives, inflammable and explosive materials, poisons, and other items that endanger safety. in a public place to cause an explosion or other terrorist threat.
To complete this series of inspections, it is necessary to use the help of security inspection equipment. The security inspection equipment mainly includes X-ray security inspection machines, security doors, hand-held metal detectors, dangerous liquid detectors, drug, and explosive detectors, etc. This principle is used to check whether you are carrying illegal items. It has been widely used in public security anti-terrorism, transportation, performances, and other fields. Let's look at the specific process below:
First, you put your backpack, luggage, etc. on the X-ray security inspection machine(X-ray baggage scanner), and the conveyor belt transmits your items to the inside of the machine for X-ray scanning, and outputs images for inspectors to determine whether contraband is entrained. With a clear imaging effect, with the help of multiple image processing functions, it can easily and quickly assist inspectors in distinguishing different substances.
Generally speaking, organic substances such as plastics, food, clothing, etc. are displayed in orange or yellow, metal inorganic substances such as iron, copper, steel, and silver are displayed in blue, and the overlapping places of organic and inorganic substances are displayed in green, and some are too thick or too dense. Since the object cannot be penetrated by X-rays, it is displayed in red (such as lead plate, gold, etc.).
(Safeagle X-ray baggage scanner scan image)
Next, you will walk through a security gate, which includes a metal detection gate and a temperature detection metal detection integrated security gate. The door panels on both sides are equipped with sensors that can transmit and receive alternating electromagnetic fields. When the metal conductor is affected by the alternating electromagnetic field, an eddy current will be generated inside, and the current will emit a magnetic field with the same frequency and opposite direction as the original magnetic field. Metal detectors capture the signal. When the metal carried by the person exceeds the preset parameter value according to the weight, quantity or shape, the security gate will immediately alarm and display the location of the metal that caused the alarm, so that the security personnel can find out the metal carried by the person in time. metal objects.
The temperature detection and metal detection integrated security inspection door is equipped with a high-precision body temperature detection probe at the door. The detection angle can be moved up and down, which can measure the surface temperature of the human forehead, and then obtain the actual body temperature according to the relationship between the temperature of the human forehead and the body temperature. . The optical components of the detector collect the energy emitted and reflected from the body to the sensor, and the electronic components convert this information into temperature readings and display them on the display panel. When the temperature reading exceeds the high-temperature alarm value, the instrument will sound an alarm.
Then, maybe the metal parts on your clothing trigger the security door alarm, and the security inspector scans your body back and forth with a hand-held metal detector. Similar to a metal detection door, it detects you through the principle of electromagnetic induction. When the hand-held metal detector sweeps over the human body, if it makes a low sound, and the sound will gradually disappear after the probe stays above the sounding place, it can be determined that it is a small piece of metal, such as a belt buckle, zipper, etc. . If the sound is very high-pitched, and the sound is continuous even when the probe is stationary, it is likely to be a larger piece of metal, such as a dagger, a pistol, etc.
Finally, after you passed the above inspection, the security inspector motioned you to take out the water bottle in your backpack and put it on the desktop dangerous liquid detector or check it with a hand-held dangerous liquid detector. The detector determines the type of liquid by measuring the dielectric constant and conductivity of the liquid to be measured by microwave reflection method, thermal conduction method, or quasi-static computed tomography. This detector can distinguish liquid explosives, gasoline, acetone, ethanol, banana water, and other flammable and explosive liquids from safe liquids such as water, cola, milk, juice, etc. without direct contact with the liquid. You are required to drink the liquid from the bottle to prove it is safe to drink.
The above is the security inspection methods that we often encounter in daily life. Of course, if you are going to the airport, there will also be processes such as drug and explosive detection. When entering the airport, the staff will take a small "test paper" to wipe your clothes, luggage, and even your hands, and then send the paper to the drug/dynamite detector for inspection.
What happened when you went through security? - Safeagle