摘要 |
A passive marker is placed adjacent to a structure in order to locate that structure after burial. The marker has a tuned circuit arrangement contained within a housing. The tuned circuit arrangement has plural tuned circuits that are oriented substantially orthogonally to each other. A multidirectional response pattern is produced by the tuned circuit arrangement, which pattern is broader than the directional response pattern of a single tuned circuit. The housing is divided into two hemispheres for ease of assembly. Each hemisphere has channels formed therein for receiving the respective tuned circuits. The channels can be formed by the exterior wall of the housing, interior walls of the housing, or in an interior spherical mandrel.
|