The study aims at examining the behaviour of electromagnetic actuator as inductive
sensor. The electromagnets are integrated in an alternative Wheatstone bridge and powered
with alternative tension. This circuit allows the measurement of the electromagnet
inductance variation, and as this variation is a function of the air gap, the displacement
can be deduced. The effect of eddy currents is assessed in order to choose the suitable
bridge frequency. Finally, a demodulator is used to obtain the tension proportional to the
air gap value. The behaviour is assessed experimentally. Experiments are carried out on a
simple beam; clamped at one end and simply supported at the other. The displacements could
be measured by using four eddy current sensors and the inductive sensor. The inductive
sensor displacement and a modal approximation of the four eddy current sensors resulting
from impact testing are compared. Analysis of the results obtained predicts an efficient
and robust behaviour.