IED Trap Range

[ahowe42]

What is the range of damage for an IED trap?  I like to put them near my turrets, so when raiders try to walk up to the turret and damage it, they blow up.  Each time I do, though, even if the turret is protected by a sandbag, it also blows up.  I'm happy the raider dies, but then I defeated the purpose of protecting the turret...

Andrew