In a hybrid jumping (HJD) or hybrid scavengeless (HSD) development station used
in xerography, a control system avoids arcing conditions in a gap between a donor
member and an image receptor. In a set-up operation, a series of test patches are
produced while incrementing the AC amplitude in the gap. A change in reflectivity
of the patches as a function of the AC amplitude in the gap is measured and the
actual width of the gap is thus estimated. An accurate estimate of the gap width
can then be used in a control algorithm.
