How well do US Digital encoders work in a dusty environment?
US Digital encoders are fairly robust to dusty environments. The encoders look at multiple sets of window and bar pairs. Thus a speck of dust at any one window will be averaged out by the other sets of windows and bars. Because of this averaging effect, a number of windows can be covered completely and the module will still not lose a count. The phased array differential modules that read the disks have plenty of signal margin. An impressive demonstration of this is to color the disk completely black with a Sharpie pen. The encoder will continue to work without errors.
