Is the security machine harmful to the body?

Is the security machine harmful to the body? Like the light we can see with the naked eye, X-ray is also an electromagnetic wave. Only the wavelength of visible light is long, the energy is small, and the penetration ability in the substance is weak; the X-ray wavelength is short, the energy is large, and the penetration ability in the substance is strong. The penetrating power of X-rays is also related to the density of matter. The greater the density of matter, the more absorption of X-rays. Medical X-ray imagers use this property of X-rays to distinguish between bone and soft tissue. X-ray irradiation is ionizing radiation, and excessive X-ray irradiation can cause damage to living organisms, so X-ray diagnosis and treatment cannot be abused unless necessary.

The baggage X-ray security instrument has the same principle as the medical X-ray imager, but because the imaging quality requirements of the baggage screening are not as high as medically, the intensity of the X-ray in the baggage security device is much smaller, and the radiation dose is about medical X. 1% of the light imager. When the baggage passes through the security device channel, the impact on the items is basically negligible. Moreover, the four sides of the baggage security device are shielded with a certain thickness of the lead plate, and the baggage security inspection channel is also blocked by the lead rubber curtain, which can reduce the radiation dose on the outer surface of the security device by about two orders of magnitude. The radiation outside the baggage X-ray security device is small, but care should be taken not to reach into the lead rubber curtain to take the baggage.

The airport security X-ray full-body scanner uses backscatter X-ray detection technology, which uses lower-energy X-rays and can only enter human skin tissue for a few millimeters. When X-ray collides with electrons in the object to be measured, energy is lost, and the amount of energy loss is related to the density of the object to be measured. The X-ray full-body scanner detects the X-ray energy and intensity changes reflected back, thereby distinguishing human skin tissue and metal objects such as weapons and weapons. Because the energy and intensity of the X-rays used in the whole body scanner are low, the radiation dose received by a whole body security test is about one-fifth of that of a X-ray film, and the effect is relatively small.

X-ray security inspection machine, also known as security inspection machine or baggage security inspection machine. Everyone is familiar with it. It is the main baggage screening equipment for subways and airports. The principle is simple, the ability to use X-rays to penetrate substances. The density is different, the thickness is different, the composition is different, and the penetration ability of x-ray is also different. X-ray machines are based on the ability to penetrate various substances to identify objects in the baggage.

Display image of various luggage under the X-ray security inspection machine

The X-ray machine not only recognizes the shape of the object, but also displays the color. The color of each substance is different. Like organic materials, such as paper, clothing, and a variety of foods, usually orange. Mixed materials and light metals, such as those containing sodium, silicon, and aluminum, are usually shown in green. Iron, copper, silver, etc. are shown in black and blue. The degree of lightness and darkness of the above various colors depends on the density and thickness of the material.

Many people are worried that the food in their own bag will be swept away by the X-ray security inspection machine and the food will be contaminated. There is no need to worry too much about this. The X-rays emitted by the baggage screening machine have a small power and are detected once. The received radiation dose is less than 5 micro-Swarth, which is far lower than those used for radiation sterilization of food. dose. Many of the foods we eat are actually irradiated. Other countries, such as the US Food and Drug Administration and the US Department of Agriculture, can sterilize and preserve the following foods, such as frozen or frozen red meat. Poultry, fresh fruits and vegetables, and grains.