METHOD AND SENSOR FOR SEARCHING FOR LEAKAGE HOLE OF GAS-FILLED COMMUNICATION CABLE IN CONDUIT

摘要

PURPOSE:To accurately measure the distance from a manhole to a leakage position by using searching sensors, where sound absorption walls are attached before and behind a sound collection sensor. CONSTITUTION:The searching sensors Y provided with the sound absorption walls 14 for preventing a sound and an ultrasonic wave from creeping is set at the head while holding the sound collection sensor 13 there between, a pipe is inserted into a conduit 1 along the gas-filled communication cable 2 and when the sound collection sensor 13 approahes to a position where a leakage hole 13 is formed,the level meter of a measuring instrument 15 shows swing and the sound of a speaker 16 becomes loud. The position where maximum swing and maximum speaker sound are obtained is the location generating the gas leakage hole 3. A scale is provided on the surface of the pipe 10 of the searching sensors Y at constant intervals, so the distance from the manhole 6a to the gas leakage hole 3 can easily be measured.