Abstract: A method and apparatus for determining the absolute position of displacement and angle transmitters. Two individual sensors are mechanically coupled to one another in such a way that they generate sawtooth output signals with a number of periods that differ by one within a predetermined measuring range. In a first step, a difference signal is formed from the output signals of both sensors and, if negative, is corrected by a constant value. A period number signal is obtained from the corrected difference signal by deriving an integer. This period number signal and the output signal of one sensor are added to form a highly accurate, absolute output signal. Since the absolute output signal still contains errors, an auxiliary signal is formed from the absolute output signal and the modified, corrected difference signal. A window discriminator determines whether the auxiliary signal lies within a predetermined limiting range. If not, the absolute output signal is corrected by a predetermined amount.

Abstract: Position sensor having two pairs of flux-concentrating pieces, arranged in succession along a shifting direction of a permanent magnet. The pieces form a primary air gap in which the magnet may be linearly shifted and form a working air gap in which a Hall probe is arranged. To eliminate the influence of foreign magnetic fields in the axial direction, the Hall probe is arranged in the working air gap so that its direction of measuring sensitivity is perpendicular to the shifting direction of the magnet.