UHV true-absolute optical encoder is 'world's first'

Said to be the first in the industry, Renishaw's new RESOLUTE range of ultra-high vacuum (UHV) encoders is designed to offer true-absolute position feedback, sub-micron accuracy and resolutions to 1nm for both linear and rotary applications.

The devices are constructed from clean vacuum-compatible materials and adhesives to give low out-gassing rates and clean residual gas analysis, making them suitable for high performance semiconductor and scientific applications requiring vacuum compatibility to 10-10 Torr. Like the standard range of RESOLUTE true-absolute encoders, the new ultra-high vacuum variants are optimised to determine position immediately upon switch-on, without the need for any movement or battery back-up. Instant commutation means that axes are immediately under complete control after power loss, thus eliminating risks of unchecked movements or collisions. Safety is assured by a built-in separate and independent position-checking algorithm. This actively checks every reading, ensuring any potential problem is flagged before it reaches the controller. In addition, the devices use pure serial communications with cyclic redundancy check which eliminates the need for auxiliary 1Vpp signals and offers higher noise immunity. Designers can choose from a variety of linear scales in either stainless steel or ZeroMet low thermal expansion alloy with accuracy to ±1µm on lengths up to 1.13m. Mounting can be either self-adhesive, mechanical or track-mounted. Stainless steel rotary rings feature large through-holes and patented taper mounting for quick, easy and precise adjustment of eccentricity, whilst minimising shaft preparation costs.