Non-contact linear scale offers high speed-high accuracy

The RELM high accuracy linear scale is part of Renishaw's SiGNUM range of intelligent encoders. It offers high speed, reliability, non-contact performance combined with advanced features, including the 'IN-TRAC' auto-phase optical reference mark and dynamic signal processing. The system comprises the SR readhead, Si interface and 20µm RELM scale, which is offered in defined lengths. The linear scale is currently available in Invar, which provides a low thermal expansion of 1.4µm/m/°C. The system is offered with a choice of IN-TRAC reference mark positions and dual optical limits. The IN-TRAC optical reference mark is repeatable in both directions across the entire speed and temperature range (over 12m/s and up to 85°C). According to Renishaw, the robust, yet highly precise, 20µm linear scales offer a level of performance only previously available from more delicate, fine pitch encoder systems. With ±1µm accuracy and resolution to 20nm, RELM can satisfy the most demanding precision motion applications. The company's SR readhead is sealed to IP64 and offers high speed, high temperature performance (over 12m/s and up to 85°C). Like all Renishaw encoders, it benefits from unique filtering optics, which provide excellent immunity to dirt, dust and scratches. The RELM scale is easy to install and can be mounted directly to the substrate using mechanical clips or a specially formulated adhesive backing tape. The Si interface can be mounted remotely and a small connector on the readhead can easily be fed through machines where access is restricted. As part of the SiGNUM range, the RELM encoder system benefits from SiGNUM intelligent signal processing, which ensures excellent reliability and ultra-low cyclic error (typically less than ±40nm). SiGNUM software is also available which enables optimum set up and real time system diagnostics via a PC's USB port.