World Environment Day — X-ray security inspection machine
June 5 is World Environment Day determined by the United Nations General Assembly. It reflects the understanding and attitudes of people around the world on environmental issues and expresses humanity’s yearning and pursuit of a better environment. It is one of the main media through which the United Nations promotes global environmental awareness, raises the government's attention to environmental issues and takes action.
On this day, most countries in the world will hold a series of publicity activities to raise the awareness of the whole society to participate in environmental protection and build a beautiful home on the earth. In the next few days, we will share with you the knowledge of World Environment Day and promote the better participation of all sectors of society in the work of biodiversity conservation. Today, the editor will take you to understand "X-ray safety".
Friends who often take the subway, train, and plane. I will not be unfamiliar with this machine. Yes, this is the X-ray security inspection machine that plays an important role in traffic security.
I believe that when everyone saw this magical machine for the first time when they were young children, they would definitely cast a curious look at this machine that can see through without opening the luggage. How can the X-ray security inspection machine see? What? Will the X-ray security screening opportunities that we often pass have an impact on our health?
What can the X-ray security inspection machine see? How did you see it?
X-ray is also called roentgen ray. It is a kind of ray that is invisible to the naked eye. It has the ability to penetrate materials, but its penetration power is different for different materials, so the amount of X-ray reaching the screen or film is different. By forming images with different contrasts between black and white on a screen or X-ray film, you can clearly see the inside of the object.
I believe everyone has been irradiated with X-rays during the physical examination. However, the X-ray security inspection machine is very different from the X-ray machine used in the hospital. The internal components of the human body are very consistent. They are all meat and bones. However, our luggage is diverse. Security checks not only need to observe the shape of the objects in the luggage, but also very important for the identification of the materials in the luggage. The medical X-ray machine uses a single set of detectors and can only generate black and white images. How to distinguish dangerous items in luggage? This can't trouble the smart and intelligent R&D personnel. The researchers used two sets of detectors in the X-ray security inspection machine to emit high-energy and low-energy signals, so that two sets of data can be obtained. It seems that a point can be determined by determining x and y on a rectangular coordinate system. By analyzing the two sets of signals through the computer, the material of the object can be more accurately known, and then the items in the package can be basically reflected through different color markings.
On the monitor of the X-ray security inspection machine. The picture you see looks like this