WATER ALARM AND FAULT-LOCATING FOR AIR CORE PLASTIC-INSULATED TELEPHONE CABLE

摘要

A broad design for remote electrical detection of relative humidity level and liquid water in a telephone cable, while avoiding false alarms due to high relative humidity. The alarm circuit relies on a plastic barrier between one pulp insulated conductor and a second conductor. The barrier is interrupted at separated intervals along the cable, for which points only the pulp insulation separates the two conductors.