Manufacturing parts of position measuring system, comprises providing metallic piston rod of pneumatic cylinder with ferromagnetic core, providing core surface with surface structure, and applying coating system covering surface structure

The process comprises providing a metallic piston rod (1) of a pneumatic cylinder with a ferromagnetic core having high magnetic susceptibility, where the metallic piston rod is operated along a magnetic sensor device during a measuring process, providing a surface of the core with a surface structure changing the magnetic susceptibility along a predetermined measuring direction, and applying a coating system (9) covering the surface structure, where the coating system has low susceptibility than the core, and is partially applied by a powder coating such as a powder flame spraying process. The process comprises providing a metallic piston rod (1) of a pneumatic cylinder with a ferromagnetic core having high magnetic susceptibility, where the metallic piston rod is operated along a magnetic sensor device during a measuring process, providing a surface of the core with a surface structure changing the magnetic susceptibility along a predetermined measuring direction, and applying a coating system (9) covering the surface structure, where the coating system has low susceptibility than the core, and is partially applied by a powder coating such as a powder flame spraying process. The surface structure is formed in the form of radially symmetrical grooves (5, 7), which form wave crests and wave troughs in sinusoidal flow at an outer side (11) of the core. The grooves are formed by winding with a depth of 500 mu m. A coating completely filling the grooves is produced by the powder flame spraying process, is thermally treated, and is sharpened for the formation of a smooth outer side. The thermally sprayed coating is post-treated by induction melting. A chromium layer is thermally sprayed for the formation of the coating. A layer made of non-ferromagnetic nickel is thermally sprayed onto the groove structure and the chromium layer is sprayed on the non-ferromagnetic nickel layer. The coating is thermally sprayed in a layer thickness such that the smooth outer side formed after sharpening is present about 50 mu m above the wave crests of the grooves. An independent claim is included for a measuring device. Ein Verfahren zum Herstellen von Teilen eines Positionsmesssystems, bei dem die metallische Kolbenstange (1) eines Arbeitszylinders beim Messvorgang entlang zumindest einer Magnetsensoreinrichtung verfährt, mit den folgenden Schritten: - Vorsehen einer Kolbenstange (1) mit einem ferromagnetischen Kern hoher magnetischer Suszeptibilität; - Versehen der Oberfläch