Multiple concert venues in my city use these, so I interact with them all the time. They have replaced standard metal detectors, bag searches, and manual patdowns w/ hands and/or metal-detecting wands. Security checkpoints are the primary point of delay for getting into venues, and places that have rolled these out process people through about 95% faster. It's a huge difference. If it does trigger, you just get the m…
I guess on a more general level, I'm confused why a metal detector with bit some machine learning on top wouldn't make a better widget? You'd think that different shape metal object produce different magnetic flux, and there's probably more dimensions to that than just size?
If you have a conveyor belt system and a CT scanner like setup then yes, you could build a better metal detector.