RGS20 glass scale linear encoder system

The RGS20 is a linear encoder scale from Renishaw with a 20 micrometre pitch, used together with RGH series optical readheads such as the RGH22 and RGH24. Contrary to the ‘glass scale’ wording of the request, the RGS20 is a gold-plated stainless steel tape scale fixed with self-adhesive backing, and the version RGS20-S is the standard type. The scale is laid along a machine axis and read without contact by the readhead, giving incremental position feedback with resolutions down to the sub-micrometre range after interpolation. The tape has an expansion behaviour close to that of the substrate it is bonded to. Typical applications include machine tools, semiconductor and electronics assembly, and general precision linear axes.