Biased-plate characterization of pulsed DC ionizers

The operation of a pulsed DC air ionization system was studied in a side-by-side comparison using a charged-plate monitor (CPM) and a biased-plate monitor (BPM). When the pulse period is short compared to the decay time, both methods give equivalent results. When the pulse is not short, however, the CPM suffers from a random error on the order of the pulse period. In addition, the CPM method is quite sensitive to the motion of persons and other objects in its vicinity. Neither of these errors occurs with the BPM, which therefore provides a significantly faster way of adjusting pulsed DC ionizers.