Abstract: An air ionizing module and method for generating ions of one and opposite polarities within a flowing stream of air or other gas includes a thin-filament electrode mounted within the flowing stream in regions thereof of maximum flow velocity. The thin-filament electrode is mounted in a multi-sided polygonal configuration to receive high ionizing voltage of alternating one and opposite polarities to form an intense stream of ions toward an electrically-isolated reference electrode positioned upstream of the filament electrode. Another reference electrode positioned within the flowing stream downstream of the filament electrode receives a bias voltage of selected polarity to control the quantities of generated ions of positive and negative polarities in an outlet stream of the ions and flowing gas.

Abstract: Apparatus and method for generating and controlling flows of positive and negative air ions includes interposing isolated sets of electrodes in a flowing air stream to separately produce positive and negative ions. The rates of separated production of positive and negative ions are sensed to control ionizing voltages applied to electrodes that produce the ions. Variations from a balance condition of substantially equal amounts of positive and negative ions flowing in the air stream are also sensed to alter bias voltage applied to a grid electrode through which the air stream and ions flow.

Abstract: An enclosure for transporting semiconductor wafers includes a pair of sensors that are responsive to electrostatic fields mounted on conductive grounded plates in facing orientations on opposite sides of a position within the enclosure at which a semiconductor wafer is to be located. Electronic circuitry within the enclosure in communication with the sensors supplies monitoring signals to remote circuitry external to the enclosure that isolates sources of contaminants and provides remote balance and gain adjustments. Calibration of the balance and gain adjustments uses a grounded plate for zero balance reference, and uses a plate of insulating material that is charged to a known potential for referencing gain adjustments to produce related outputs.