A process of adapting mechanical tolerances of a transmitter wheel provided with a plurality of approximately equidistant markings which are sensed by a pick-up supplying a pulse train whose time interval is measured and stored, includes connecting a transmitter wheel with a rotating shaft of an internal combustion engine, carrying out a check as to whether or not the internal combustion engine is in thrust operation, and placing a second and following time intervals in relation to a first time interval when the thrust operation is detected.