The Science of Airport Security

This machine is either a backscatter X-ray  or millimeter wave scanner.  If the machine just looks like a flat wall,  it’s probably a backscatter X-ray scanner.  These use very small amounts of weak X-rays  that only penetrate your clothes, and don’t  go through your skin.  The machine detects the radiation reflected  by your skin and anything else under your  clothes, and generates an image that easily  shows anything you’re trying to conceal.  The amount of X-ray radiation you’re exposed  to in a backscatter scan is extremely low,  a tiny fraction of the amount you’re about  to be exposed to by flying on a plane.  But still, this technology isn’t used very  often, and it’s banned in many countries.  Instead, millimeter wave scanners are much  more common.  They’re the cylindrical machines that look  like futuristic phone booths, and they use  the same basic principles as backscatter scanners. if you either want to travel to airport select shuttle service

Checking Through X-rays

But instead of X-rays, they emit microwaves,  which are non-ionizing, meaning that they  can’t damage your DNA, and you don’t need  to worry about exposure.  Since millimeter waves can penetrate through  clothing, they can still show if you’re  hiding something that you shouldn’t be.  Once you make it through the scanner though, you might still be in for some follow-up tests.  If security finds anything in your bag  that looks suspicious, they’ll probably  swab you for traces of explosives.  A security officer might swab your hands,  your shoes, or your bag, then place the swab  in yet another machine for analysis.  This is the Explosives Trace Detection machine,  or ETD.  The idea here is that, if you’ve been handling  explosives, or if there were any inside your  bag, the swab will pick up traces of suspicious , compounds.  To analyze the swab, the ETD uses a process  called ion mobility spectrometry.  The machine gives the molecules on the swab  an electric charge, turning them into ions.  Then, a gas carries the ions through a tube.  Different ions will take different amounts  of time to pass through the tube, depending  on things like their mass and charge.  The machine then identifies different compounds  based on how long it took them to move through  the tube.  So, airport security might be tedious and  annoying.  But at least now you know what’s happening  to you and your carry-on. 

Leave a Reply

Your email address will not be published. Required fields are marked *