Patent ID: 8234942

Claim:
A nondestructive inspection apparatus adapted to inspect a structure having an interior opening portion defined by a plurality of walls having exterior and interior surfaces, comprising: an inspection apparatus outer probe unit having a plurality of outer probe unit walls each having a surface corresponding to a respective one of the plurality of exterior surfaces of a respective structure wall, the outer probe unit comprising a first outer probe member and a second outer probe member, magnetically coupled to each other to thereby force at least one outer probe unit wall on the first outer probe unit member and at least one outer probe unit wall on the second outer probe unit member into close proximity to a respective exterior surface of the structure, through magnetic attraction between a magnet on the first outer probe unit member and a magnet on the second outer probe unit member; and a magnetic balance positioned to force the second outer probe unit member in a direction of increased magnetic coupling of the second outer probe unit member to the first outer probe unit member through magnetic repulsion between a magnet on the magnetic balance and a magnet on the second outer probe unit member.