An eye test for x-ray vision
New technology a boon to maintaining border security screening.
Anyone who has patiently queued through airport security with their jacket off and laptop in hand knows how seriously countries take border security. Bags, computers and even shoes are carefully checked by X-ray machines for clandestine objects. On a grander scale, X-ray machines large enough to scan whole shipping containers protect our seaports and airports from the importation of illegal goods.
In tip-top condition, these giant machines can spot items as fine as the spokes of a bicycle wheel in a densely packed shipping container. But the scanners need careful maintenance to keep their X-ray vision sharp.
Giving one of these machines an eye test was once a labourious, two-day task, but a new test kit developed by ANSTO cuts this process to half an hour. The kit is already used around Australia, and has just been licensed by a Singapore-based firm called Lighthouse Global Technologies for sale across Asia, with an option to go global.
ANSTO first developed the technology after its X-ray experts were asked to help assess whether container-scale X-ray scanners used at Australia’s ports were performing as well at detecting explosives as their manufacturers claimed. The team soon decided that the painfully slow test process, which involved repeated scans to detect progressively smaller metal objects, could be streamlined, explains Mark Reinhard, ANSTO’s program leader for nuclear security research.
The group designed a pair of truck-mountable metal frames, which contain a variety of different X-ray imaging tests. In one test a series of increasingly fine metal rods is attached, hidden behind multiple layers of steel, to accurately measure a machine’s resolving power in just a single scan.
“We can drive that truck into the screening facility, perform the X-ray analysis, and complete the test in about 30 minutes,” says Reinhard. Accompanying software gives the scanner a score that indicates whether a tweak or two will be needed in the next scheduled maintenance round, or whether more urgent attention is warranted.