CONNECTION BOX FOR OPTICAL FIBER-CONTAINING OVERHEAD EARTH-WIRE

摘要

PURPOSE:To enable the early detection of lowering of airtightness by fitting a connection box for optical fiber-containing overhead earth-wire with a pressure gauge. CONSTITUTION:A connection box 10 has an O-ring 15 so as to keep the inside airtight. A laid optical fiber-containing overhead earth-wire 7 is received by the side face 11a of the body part 11 and its termination is fixed at the connection box 10 by a clamping part 20. A gas pressure gauge 25 and a valve 26 are fitted in the through hole 21 of said connection box 10. If a filler gas is charged via a valve 26 and its pressure is monitored by said gas pressure gauge 25, the inspection of airtightness can be performed easily.