A method of determining a surface profile of an electrically conductive object, using probe comprising a transmitter/receiver arrangement for inducing transient eddy currents in the object, for providing a signal indicative of a magnetic field property, the method comprising: a) selecting a calibration point on the surface, and a number of calibration positions of the transmitter/receiver arrangement; b) determining a set of calibration values by determining, for each of the calibration positions, a characteristic value of the signal generated in the receiver in response to transient eddy currents induced in the object by the transmitter, wherein the characteristic value relates to the amplitude of the signal; c) determining a calibration function which relates the calibration values to the relative location of calibration position and calibration point; d) selecting a set of inspection points on the surface of the object, and a set of corresponding inspection positions of the transmitter/receiver arrangement; e) determining a set of inspection values by determining, for each of the inspection positions, a characteristic value of the signal generated in the receiver in response to transient eddy currents induced in the object by the transmitter; and f) determining the surface profile by interpreting the set of inspection values, using the calibration function, wherein the relative location of inspection points and corresponding inspection positions is derived.