Air-side walk-through light boxes. What are they?

Question

To disembark in many European terminals, passengers must pass through a corridor with a bottleneck. On either side of the hallway there are tall, chubby boxes. The white or gray boxes are powered and sometimes illuminated.

Usually they are unattended, with red lettering reading "one person at a time" and ignored for the most part by passengers. Not to be confused with:

• light box ads
• body scanners
• metal detectors
• luggage screeners
• one way gates or airlocks

But referring specifically to these oversized panels which passengers must pass between. They are usually near passport control or near customs, prior to the arrivals lobby exits.

What are these?

(This image is the nearest can find to an example -- sometimes they are adjoined by overhead bar, sometimes not. Notice the absence of the boxes at the "goods to declare" passage)

Answer 1

The device in your image is most likely a Southern Scientific Pedestrian Radiation Portal Monitor. I'm only unsure of the bottom, darker protruding part, the rest looks exactly like the only image the producer released up to the position of dark spots.

The machine is used to detect traces of gamma and neutron radiation, which may be a result of nuclear weapons.

It's a bit better to see the device installed in this image.

The devices have been in use for quite a time. There even haven been several papers published such as this one in the medical journal The Lancet about setting those devices off after certain medical tests.