The Mercury II digital encoder, for high-performance motion-control applications, is available in four models with resolutions ranging from 5- µm to 1.2-nm linear or 20k to 268M-CPR rotary. The encoder achieves ±25-nm accuracy with glass scales. Operating speed at 50-nm resolution is 2 m/sec. The miniature sensor fits space-restricted motion-platform designs and works with adhesive-backed PurePrecision laser-tape scales, as well as glass-linear and glass-rotary scales. The encoder has stick-on bidirectional optical index and limit markers, which let designers configure the scale to the application during production. The Mercury II has a ±2° sensor-alignment tolerance.