Customs scanners
 

You know how some countries have big scanners that you walk through in the customs area when you arrive? They look like huge metal detectors. What are those things scanning for? Weapons? Electronics? Undeclared fruits and veggies?

Yes

My wife tripped one in Shanghai--nuclear. It caught the nuclear heart scan she had the day before. I was quite unimpressed with how they handled it--totally focused on finding the reason for the false positive, no attempt to figure out if it actually was real. (It would have been simple enough to check her for hot spots with a geiger counter, they didn't. She had left the card from the lab at home, they simply took her word for it. At least that was better than the US police that did the opposite--set up a radiation detector and threw everyone that tripped it in jail. 100% were from nuclear medicine, zero smugglers.)

Yes.. because a Geiger counter is standard equipment everywhere.... I carry my own of course... ;):D

If you're going to set up a big radiation detector you should give the people manning it small ones also to locate what the big one found. What China did was simply stupid. (And then we hit a second detector going out of customs. It triggered, we stopped and waited and eventually gave up and continued when nobody responded.)

A geiger counter isn't perfect because while the residue of nuclear testing will show up as whole-body radioactivity people with radioactive seeds implanted will show a hot spot like a smuggler. (I don't know how many of those would be traveling, though.) Radioiodine will also show up as whole body with a big hotspot.

I have noticed the radiation scanners in several airports on the Eurasian continent east of the Schengen area.

They do resemble metal detectors but don't have a roof IIRC, rather a big panel (bigger than a metal detector) left and right, seemingly always in gray colors.

The one we hit in Shanghai looked like a metal detector but it didn't make sense for there to be one at that location. I'm used to security-nonsense metal detectors in China, though, and didn't think anything of it until she triggered it.

The radiation detectors that I used to notice post-baggage claim in some parts of Europe reminded me of just more substantive anti-shoplifting walk-thru detectors that some stores have.

I got nabbed by one of these scanners in Chisinau. I didn't hear a beep or anything but the guy told me to come to the side for additional screening. They scanned by bags and asked me about laptops. They told me that I had to pay an import tax on one laptop as only a single laptop is allowed duty free. I showed them the laptops and showed them that one had my company sticker on it and the other was several years old. They finally let me pass. I guess people go abroad and buy laptops for cheap and bring them here without paying the tax.

Never seen these scanners in the US and I'm not even sure how they choose to screen passengers there.

Indonesia is big on conveyor belts at customs. I believe the Middle East is, too.

Some countries have the scanners before it is loaded onto the baggage belt. Then you see the secondary screening machines as you depart the customs area. It is also used for checking drug smuggling. The colour monitors show substance in the baggage and if they suspect then it is screened at the exit point again.