metal detectors at entry
Apparatuses at the entrance which screen persons for metal objects being carried in.
Metal detectors at the entrance to an area are electronic devices where persons entering a building or other place are screened to detect any substantial metal objects being brought in. This is done mainly to prevent the ingress of firearms and explosives. Metal detectors are often accompanied by baggage inspection points, so that metal objects can be examined separately to ensure that they are harmless.
This feature is especially common in airports and government buildings.
The devices screen people entering for substantial metal objects. Baggage inspection can accompany them but is a separate feature; neither an airport location nor that companion inspection is mandatory.