The RELM line of high accuracy encoders from Renishaw combine accuracy to +/1 micron/m and resolution to 23 nm with speeds above 10 m/s and temperatures up to 85 degrees C. Initially available in Invar, which provides a low thermal expansion of 1.3 microms/m/K, the RELM scale offers a choice of IN-TRAC reference mark positions and dual optical limits. Robust, yet precise, the 20 micron spars allow the RELM to offer a level of performance previously available only from more delicate fine-pitch encoder systems. Non-contact performance provides high reliability to satisfy demanding precision motion requirements and high throughput manufacturing operations. The advanced SiGNUM RELM linear encoder system comprises the SR readhead, Si interface, 20 micron RELM spar in defined lengths and advanced features including IN-TRAC and intelligent signal processing. The IN-TRAC auto phase optical reference mark is repeatable in both directions across the entire speed and temperature range. According to the company’s press release, the SR readhead is sealed to IP64. Its filtering optics provide immunity ot dirt, dust and scratches. The RELM scale can be mounted directly to the substrate using mechanical clips or a specially-formulated adhesive backing tape. The Si interface can be mounted remotel and a small connector on the readhead can easily be fed through machines where access is restricted.