They're also used in larger capacities in the loading area of airports. Some are so large that a huge platform palette can be loaded onto an X-ray to image hundreds of bags at once. Linescan is also utilized in protecting against the threat of explosives being brought on the aircraft. Automated explosive detection systems were developed to answer the limitations of linescan capabilities. Explosives generally have a lower atomic number than other common objects such as clothing, wood, plastic and glass.
High density is indicative of an explosive.
If you find something which has a low atomic number and high density, you have a pretty good guess that object is explosive. The images are fed into a computer, which is used to reconstruct an image of the internal structure of the person or object. Increase presence of uniformed and plainclothes security personnel in all areas of the airport. Develop a schedule for increasing security inspections in passenger terminals. Increase frequency of random ID checks.