Abstract: An apparatus for measuring differences by incrementally counting graduations has additional equidistant graduations as well as a corresponding sensor and evaluation device. The intervals between the marks of each additional graduation are multiples of one interval of an incremental graduation. The intervals of one additional graduation differ from those of others by an integral number of incremental intervals. A simple determination of the absolute position of marks from a zero position is done by using an incremental counter for counting the steps between successive marks of two of the additional graduations. This method requires only small motions of the carrier and sensing of the zero position itself is not required.