Pass the security check

The security inspection machine is a device that is often seen at stations, airports, exhibitions, etc., and is used to check the electronic equipment that the entry and exit personnel carry with them.

Security inspection principle:

When the baggage enters the X-ray inspection channel, the package detection sensor will be blocked and the detection signal will be sent to the system control part to generate an X-ray trigger signal, and the X-ray source will emit an X-ray beam. The X-ray beam passes through the inspected object on the conveyor belt, X-rays are absorbed by the inspected object, and finally the semiconductor detector installed in the channel is bombarded. The detector converts X-rays into signals. These weak signals are amplified and sent to the signal processing chassis for further processing. These signals are processed and displayed on the display. And displayed as yellow, green, black and so on. Generally yellow objects are organic, such as plastics, food, etc., are safe, while green, black objects need attention, if there are many green or black objects, or in the shape of a head or knife, it is generally *branch, **, Controlled * items and other items; In addition, X-ray security inspection machine display image system, there will be * * Drug auxiliary functions: auxiliary detection * product * medicine and other dangerous goods, and sound and light alarm function: sound and alarm when the conditions are met Light signal.

The security machine checks the baggage, but if the person enters the security inspection machine, it is unsafe. The harm is mainly reflected in two aspects. One is the radiation effect of the security inspection machine, and the other is that the child will be stuck.

It is understood that the lead screen of the X-ray security inspection machine can prevent radiation from radiating. When the machine is in normal use, passengers must not lift the lead curtain. Although the amount of radiation that the hand puts into the lead curtain is better than the X-ray exposure, The amount of radiation received by the film is even smaller, but it is still not necessary to lift the lead curtain. Some passengers are not allowed to take the lead curtain immediately after they are stopped by the lead curtain because they are carrying a small bag. The act of doing so must not be carried out. The transport belt will bring the bag out. Although the radiation of the security inspection machine is an important factor for everyone's concern, but everyone does not have to worry too much. Shenzhen once investigated the subway security inspection machine. Meet the relevant requirements of GBZ127-2002, compliance rate was 100%. The security inspectors work for an average of 8 hours a day, with an exposure dose of approximately 0.4 millisieverts/year, well below the national standard of 20 millisieverts/year.

While sitting in the National Security Examination of the Metro, it is often seen in the process that children play with their hands and touch the security machine, but many parents do not pay attention. There have been experiments with this situation.

In Beijing, a large-scale company specializing in the production of security inspection equipment, there is a warning sign that carefully handles the hand in the gap between the security inspection conveyor and the shelf. Purchased a child's arm model from the medical supply store for experimentation. The model's size is equivalent to that of a 7-year-old child's arm, and the surface is made of silicone material, giving it almost the same texture as the real arm.

Move the model arm to the gap between the security inspection machine and the rack. As soon as the model's hand was caught in the crevice, the roller on the shelf was suddenly arched. Slightly upward, the model arm is removed from the gap. Originally, this roller was not directly fixed to the rack, but was connected to the U-shaped ports on both sides through steel wires. The staff member said that on the basis of the strict implementation of the standards, the addition of this design can better ensure safety. Once the person's hands are accidentally caught in this gap, the roller will be arched and the gap will immediately follow. Broadening, the hand will have the opportunity to pull out from the gap, thereby reducing accidents.

But what if the arms are not removed in time? In just 3 seconds, the model arm was firmly stuck in the gap between the conveyor belt and the rack. What's even more frightening is that the silicone-mimicking skin has also been crushed. If this is a real child's arm, the damage can be imagined!

So, is it really easy for real children's hands to fit into this gap? Using a caliper, measure the width of this gap. It also measured the thickness of the fingers of four children aged 5 to 7 who were fat and thin. It is approximately between 7.93 mm and 9.76 mm and less than the width of this gap 11.05 mm. It seems that children's hands can not only enter this gap, but if they panic after being pinched, they cannot get it out in time or they will be pinched.