I know police are always equipped with guns in some areas.
And terrorist attack is increasing these years.
But for security members, especially for public security, is it necessary for them to carry metal detecting tools?
I've used the arches and the wands. Realistically, they are more trouble than they are worth. They give too many false triggers from belts, jewellery, metal bits in shoes etc. but aren't that good at finding things if they aren't close to the part where something is or are moved too fast. Realistically, you'd need about 8 sweeps down the body to get close enough to all areas, bodies are round, wands are flat.
Then you can have blades that aren't metal, explosives aren't metal and the little bits you need to detonate them could be hidden in a shoe or boot that has other metal.
I think if you're going to search pat-down searches are better, wand or arches are more just to give an appearance of security.