Method for detecting at least one reference mark (57) of a set of increment marks of a sensor wheel (53, 54), wherein the set of increment marks comprises normal increment marks (55) and at least one reference mark (57), wherein a first sensor
signal is detected upon a rotational movement of the sensor wheel (53, 54), wherein a normal increment mark (55) and a space (56) following the normal increment mark (55) generate a first increment profile with a first increment period in the first sensor
signal, wherein the reference mark (57) and a space (56) following the reference mark (57) generate a second increment profile with a second increment period in the first sensor
signal, wherein a second sensor signal is detected at the same time, wherein the second sensor signal is equal to the first sensor signal but phase-shifted by a first
phase angle with respect to the first sensor signal,wherein at least one unit (26) for determining a direction of rotation determines a first or second direction of rotation, wherein at least one unit (40) for detecting the reference mark (57) detects the reference mark (57) as a function of the direction of rotation, the first and the second sensor signal, wherein the at least one unit (40) for detecting the reference mark (57) detects the reference mark (57) as a function of a difference signal (17), wherein the difference signal (17) is generated from a difference between the first sensor signal and the second sensor signal, characterized in that the at least one unit (40) for detecting the reference mark (57) additionally detects the reference mark (57) as a function of a summation signal (37), wherein the summation signal (37) is formed from a sum of the first and the second sensor signal.