Renishaw: REXA ultra-high accuracy absolute angle encoder REXA30USA255B

With zero coupling losses and exceptional repeatability, the REXA ultra-high accuracy angle encoder achieves better than ±1 arc second total installed accuracy.

Like the RESA encoder, the REXA is a stainless steel ring with the scale graduations marked axially onto the periphery, but with a number of differences to improve upon RESA’s already impressive accuracy.

REXA has a thicker cross-section to ensure that the only significant installation error is eccentricity. Eccentricity is easily removed by using 2 readheads, and combining the signals inside the host controller.

The only errors remaining are graduation errors and readhead SDE, both of which are so small they are often negligible. As a non-contact encoder, REXA offers dynamic performance advantages, eliminating coupling losses, oscillation, shaft torsion and other hysteresis errors that plague enclosed encoders. The REXA system operates at temperatures up to +80 °C and speeds to 8500 rev/min