Flexible probe for insertion into an auxiliary pipe extending from a main pipe

摘要

A flexible probe for insertion into an auxiliary pipe indicates the proximity of the auxiliary pipe to a device within a main pipe. The probe includes an apparatus for generating a magnetic field for detection within the main pipe. An indicator associated with the probe generates a signal when the probe is adjacent the main pipe. The magnetic field generating apparatus includes a coil with an electronic circuit for generating an alternating current signal and also includes a switch operable when the probe contacts the main pipe.