Sony Laserscale is an ultra-high accuracy linear scale using hologram grating and semi conductor laser read head.     The BL55 high accuracy scales require no separate interface, resolution to 0.01µm.   BL55-RU (Enclosed scale with zero point) BL55-RE (Open scale with zero point) BL55-NE (Compact open scale)     BS76/78 ultra-high accuracy system requires BD interface detector, resolution to 0.14 nanometer can be achieved.   BS76-NS/N (for use in vacuum) BS78 (latest compact model)   BD15 (Detector series VME card) BD60 (Detector, 0.1µm resolution) BD95 (Detector series to 0.14nm)