A barrier system comprises a housing, substantially vertical members, and vertical guide tubes. The sign may include a pair of walls that face in generally opposite directions so that messages can be displayed in two general directions, and a hook for hanging the walls from a support, such as a handrail assembly or other stanchion. The circuitry may generate a phase error signal based on the received time phase corrected Bluetooth signal, and generate a mean phase error signal based on the generated phase error signal. Scrap from edge trimming and exhaust from the suction box is returned to the formerhead. In yet another embodiment, the interrogation system includes metal interrogators capable of discerning the presence of a metal object, especially in a presence of another metal object.