A data signal indicative of a gap between a sensor and at least one of a surface of a rotor and a surface of a stator rotating relative to the sensor is sent to a computer processor. The computer implements defining a plurality of lowest values of the data signal over a revolution of relative rotation between the rotor and the stator, and displaying the plurality of lowest values for assessment of the distance between the sensor and a surface of at least one of the rotor and the stator in order to determine a position of the rotor relative to the stator.