Renishaw: RESR angular encoder system RESR40USA209

RESR40 is a one-piece stainless steel ring with 20 µm pitch graduations marked directly on the periphery. Two versions are available in a wide range of sizes (Ø52 mm to Ø550 mm).‘A' section rings, which offer an impressive installed accuracy, feature a taper mount system which reduce the need for highly toleranced machined parts and eliminate eccentricity. ‘B' section thin rings, which are low inertia and mass, are also available. Both 'A' and 'B' section rings have a large internal diameter for flexible integration. The non-contact format eliminates backlash, shaft wind-up (torsion) and other mechanical hysteresis errors that are inherent in traditional enclosed encoders.
The RESR is a non-contact optical encoder that provides good immunity against contaminants such as dust, fingerprints and light oils. However, in harsh environments such as machine tool applications, protection should be provided to prevent ingress of coolant or oil.