UVP's Stable Ozone Generators are designed as sources of stable ozone production in the range from 0.1 ppm to 5 ppm (parts per million). These devices utilize the photochemical reaction of the 185nm emission line of mercury to produce ozone from oxygen. A unit consists of a stable source of 185nm radiation, a quartz reaction duct and radiation housing. The stable radiation source consists of a Pen-Ray® mercury discharge lamp inserted into the radiation housing and an external ballast power supply. This system, coupled with an appropriate supply of dry air or oxygen of uniform flow rate, will provide a stable source of ozone for hundreds of hours of operation in instrumentation or other ozone-utilizing systems.