A failure indicator seal includes a nonmagnetic housing, a plurality of annular pole pieces having distal ends, the plurality of annular pole pieces disposed within the nonmagnetic housing, an annular, non-conducting magnet disposed between the pole pieces, a predefined quantity of magnetic fluid disposed between each of the distal ends of the plurality of annular pole pieces and the rotary shaft of a rotary feedthrough forming a plurality of magnetic fluid O-ring seals, and means for measuring resistance through the plurality of annular pole pieces, the plurality of magnetic fluid O-ring seals and the rotary shaft.