Abstract: The apparatus described is intended for the treatment of small volumes of room air for the removal of odors. Since the ozone output of the apparatus is calibrated in terms of the readily measured corona current, this type of apparatus can be intelligently applied to odor control problems. If the volume to be treated is known, then the output in mg/hr necessary to produce ozone backgrounds of 0.04 ppm and below can be readily computed. Such concentrations are comparable to the natural background and generally acceptable for continuous human occupation.