This CDC developed invention is a novel device for a miniature, nonradioactive bipolar charger to electrically charge aerosol particles for use in personal and portable aerosol instrumentation. Such devices are an integral component of aerosol instruments employing electrical mobility-based techniques. Current, commercial state-of-the-art mobility instruments employ aerosol chargers using radioactivity to achieve bipolar particle charging and, therefore, are not suitable for field-portable instruments. Due to strict regulatory restrictions on use of radioactive materials, these radioactive chargers also tend to be too bulky for use in compact aerosolization instruments.

This invention circumvents these two critical drawbacks by eliminating radioactivity and miniaturizing overall unit size (1x0.75 x 0.5 inch). Other unique aspects of the invention entail elimination of the need for additional air flows (other than the aerosol sample flow), minimal power consumption, a low per-unit cost, and simplicity of operation. In all, excellent transmission efficiency, steady-state charging characteristics and the miniature size make this bipolar particle charger well-suited for integration with portable or personal aerosol instrumentation.