This paper presents a method for detecting faults in the induction machine
using a flux sensor which measures the external radial leakage magnetic
field of the machine. The procedure uses the spectral lines that correspond
to the slotting effect which causes harmonics in the machine air gap. These
harmonic frequencies, which are about a few kHz occur in a part of the
spectra which is not very dense compared to the one that corresponds to the
low frequencies due to the supply or the rotor revolution speed. The
considered components can also be detected in the radial magnetic field
flowing out of the machine. It can be shown that specific faults lead to
additional spectral lines which appear clearly near the original ones due to
the slotting effect. Two faults, which can be detected with the same
magnetic flux sensor, are presented in this paper: the first one
corresponds to a broken rotor bar, the second one is a stator inter turn
short circuit.