Patent ID: 7320249

Claim:
An apparatus for inspecting a structure comprising: a driven probe structured for traveling over a first surface of the structure, said driven probe comprising a ring magnet and an sensor disposed within said ring magnet for inspecting the structure as said driven probe is moved over the first surface of the structure; and a tracking probe structured for traveling over an opposed second surface of the structure, said tracking probe also comprising a ring magnet for cooperating with said ring magnet of said driven probe to draw the driven and tracking probes toward the first and second surfaces of the structure, respectively, wherein magnetic attraction between said driven and tracking probes causes said tracking probe to be moved over the second surface of the structure in response to corresponding movement of said driven probe, and wherein at least one of said driven probe and said tracking probe comprise a fluid conduit for injecting a fluid between said respective probe and the surface of the structure to create a fluid bearing.