Measurement of Aerial Ozone Concentration for the Prototype Atmospheric Plasma Jets

Aerial ozone concentration during the operation of an atmospheric pressure pencil-type plasma jet, a proto type for biomedical applications, is measured as a function of the distance from the jet nozzle. Ozone concentration is below time weighted average (TWA) allowable concentration of 0.08 ppm for inert gases of (He, Ne, and Ar)-jets in the plasma current of less than 10 mA. However, air-plasma jet of a current 20-40 mA, operated with a higher voltage, generates a higher ozone concentration in the air, which exceeds the TWA limitation. Ozone concentration decreases exponentially; proportional to the distance from the area of discharge cavity, where we presume the ozone concentration to be the order of 10
²
ppm. The solutions of the diffusion equation confirm that the concentration diminishes to below 1 ppm at 20 cm away from the growth area of 10
²
ppm without considering the destruction of ozone during diffusion in the air.