traveling on airplanes means checking in at airports and having you luggage scanned.The machines that perform this duty are typically metal detectors or X-ray scanners.The principle of a metal detector involves wire coils,a transmitter and current that creates a(n) electromagnetic field.Any metallic object that enters this electromagnetic field will interrupt the current and signal a(n) alarm X-ray or CT scanning technology is used to detect the density and mass of objects.even their chemical components.In busy airports,large trucks with built-in X-ray scanners are used to scan large amounts of baggage at one time.