Abstract: The probe comprises two inductance windings mounted in opposition and conted to an a.c. generator, a measurement winding placed at right angles between the two inductance windings and a measurement voltage detector. A compensation winding is placed coaxially and symmetrically with the measurement winding in relation to the axis of the inductance windings, thus permitting enhanced sensitivity of the probe and a directional effect. Potential applications include continuous recording of magnetic susceptibility along a vertical borehole wall and ore sorting on a conveyor belt.