SHG-A precision linear glass scale reader assembly

Newall Measurement Systems supplies linear encoders for machine tools and metrology, and the SHG range is a long-established family of glass scale encoders. A glass scale with a fine grating is read by an optical readhead that generates incremental signals as it moves along the scale. The assembly is used as a position feedback device on manual machine tools with digital readouts, as well as on CNC axes. Resolution depends on the output type and interpolation, and can reach fractions of a micron. Output options are typically TTL square-wave or sinusoidal signals. The scales are mounted along the axis with the readhead on the moving carriage, and are sealed or protected against coolant and contamination. Typical applications include milling machines, lathes, grinders, EDM machines, coordinate measuring machines and inspection equipment.