The magnetic flux leakage (MFL) type non-destructive inspection can be performed only when the metal object
is sufficiently magnetically saturated. Therefore, since the general MFL sensor system used for pipeline inspection
must sufficiently saturate the pipe, the weight and size of MFL sensor system are inevitably increased
according to the diameter or thickness of the pipe. However, if the weight of the MFL sensor system is excessively
increased, it is difficult to drive, and thus it is difficult to inspect a pipe having a large diameter. In this
paper, the novel MFL sensor system which can be inspected large-diameter pipes without increasing the weight
of the MFL sensor system is proposed and compared to the conventional MFL sensor system used for the pipe
inspection. Since the proposed MFL sensor system is a system that saturates the pipe locally, it has the advantage
of being able to inspect the pipe regardless of the pipe diameter.