Tedious queues at security are up there with the most irritating things about flying, but hey – it’s worth being patient when it comes to our safety, right?
But how, exactly, do those luggage and body scanners actually keep us safe? What’s the point of the conveyor belt that ferries through your hand luggage, your little plastic bag of liquids and your devices? Read on, curious traveller – we’ve got all the answers.
What are airport body scanners actually looking for?
First, let’s start with a bit about how these scanners work. R. Carter Langston, a spokesperson for the TSA, spoke to Reader’s Digest and said: ‘Body scanners use a technology called Advanced Imaging Technology (AIT) for full-body scans at airport checkpoints. It’s a millimetre wave scanner that detects a wide range of metallic and non-metallic threats in a matter of seconds.’
‘Essentially, the machines send millimetre waves toward a passenger’s insides,’ said Shawna Malvini Redden, PhD, the author of 101 Pat-Downs, ‘The waves go through clothing and reflect off the passenger’s skin (and whatever else is concealed) and bounce back an image, which is interpreted by the machine.’
The scanners provide an avatar-like image (for individual privacy) to whoever is looking at the screen, and if the waves identify something suss (like something you’ve left in your pocket), the machine will put an alarm note on the avatar so security people know where to look. That’s why you should always remove watches, belts, coins, keys, and devices and put them in a tray.
What are they looking for? Mainly weapons, particularly those that aren’t caught by metal detectors. However, there are a few pretty random things which can set off the scanners:
- Thick hair (especially in braids or buns)
- Hair clips
- Body piercings
- Wire supports in bras
- External tumours
- Sweat (which is due to how those electromagnetic waves bounce off water)
What are airport luggage scanners actually looking for?
Scanners are looking to identify potential threats, and according to the BBC, that’s done by identifying colours and strange shapes. The ones that examine our luggage release X-rays that pass through our bags and calculate the density and mass of the contents, including metallic, non-metallic and organic objects, according to Point Security Inc. Metal comes out blue, organic materials come out orange and lighter metals come out green.
Items such as pills and money are easy for the scanners to identify, but while they can’t specifically identify drugs, they can provide clues to where they might be located – organic materials such as food, paper, explosives and drugs are marked with an orange colour on the scanners, and if your luggage contains anything that looks a bit suspicious, security will take a look.
There’s also something called ‘slicing’ luggage – though that doesn’t mean cutting it open. Instead, some airports have CT (computed tomography) scanners, like those you find in a hospital, which ‘slice’ through bags, providing a cross-section of the contents every few millimetres to alleviate any doubt.
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