(Nevit Dilmen (talk)/Wikimedia Commons)
One of the main differences is the type of wave used in each device. The so-called X-rays are waves of higher energy and very short length, capable of penetrating the human body. The body scanner, on the other hand, uses radiofrequency waves – like MRI devices – which have lower energy and longer length, being reflected by the body. This technology is increasingly present in airports, for the passenger magazine. After all, it is a much safer option than X-rays – which only come into play to analyze suitcases and objects. Due to their more invasive characteristic, X-rays emit radiation that is accumulated in the body, which would be a serious problem for anyone who travels a lot by plane.
QUESTION X
In the body scanner, waves are reflected from the body instead of passing through it.
X-RAY
1) The X-ray machine emits electromagnetic waves that cross the person’s body. Denser spots, such as bone, absorb these waves more than tissues such as skin and fat.
2) After passing through the body, the X-ray waves sensitize a photographic film. When it is “developed”, the dense parts – which retained waves – appear whiter on the plate, and the rest of the body takes on a darker tone.
BODY SCANNER
1) In the body scanner cabin there are transmitters that emit radio frequency waves. Unlike X-rays, they do not pass through the human body. As they are larger, the waves hit the person and are reflected back, being collected by various receivers.
2) Transmitters and receivers are positioned in two columns that rotate 360º, repeating the scan several times, from different angles. With this, the final image formed is a perfect 3D model of the scanned person.
3) An employee analyzes the images on a monitor, which is in an isolated room, far from the cabin. The person’s face is blurred to avoid embarrassment and, according to airport management, images are always destroyed after analysis