Abstract: The linear measuring system includes one part of a (usually steel) rod, beam or strip that is profiled with a trapezium like (subset of a) De Bruijn sequence. Each element of the alphabet is represented by a discrete height of the profile. The profile can be coated with a material with low magnetic susceptibility to enable the application on a piston rod of a pressure medium cylinder. The second part of the measuring system reads the subsequences of the main sequence by using the signals of arrays of linear Hall effect sensors, placed in a magnetic field as input for a signal processing algorithm. With a look-up table, the position of this second part of the measuring system with respect to the profile is determined. An interpolation algorithm can be used to improve the resolution to well below the sequence pitch.

Abstract: A piston rod defining a surface and including a structure on the surface configured to be traced by a position sensor during a stroke of the piston rod. The surface, and consequently the structure, are covered by a coating by build-up welding. The structure is produced in the same operation during the build-up welding of the coating. The entire structure may be formed by the build-up welding, or a coded basic profile is incorporated before the build-up welding.

Abstract: A piston rod defining a surface and including a structure on the surface configured to be traced by a position sensor during a stroke of the piston rod. The surface, and consequently the structure, are covered by a coating by buildup welding. The structure is produced in the same operation during the buildup welding of the coating. The entire structure may be formed by the buildup welding, or a coded basic profile is incorporated before the buildup welding.