The most common method of ozone generation has been the corona discharge method wherein an oxygen molecule is split into highly unstable nascent oxygen which then attaches itself to the incoming oxygen molecule and forms ozone.
The voltage required to produce ozone by corona discharge is proportional to the pressure of the source gas in the generator and the width of the discharge gap. Theoretically, the highest yield (ozone produced per unit area of dielectric) would result from a high voltage, a high frequency, a large dielectric constant, and a thin dielectric. Because of the adverse impact of temperature on the production of ozone, adequate cooling should be provided to maintain generator efficiency. Excess heat is removed usually by water flowing around the stainless steel ground electrodes.