TELEDYNE API
M703E Calibrator Operator’s Manual Theory of Operation

9.5. O3 GENERATOR OPERATION

9.5.1. PRINCIPLE OF PHOTOLYTIC O3 GENERATION

Ozone is a naturally occurring substance that is sometimes called "activated oxygen". It contains three atoms of
oxygen (O3) instead of the usual two found in normal oxygen (O2) that is essential for life. Because of its
relatively short half-life, ozone cannot be bottled and stored for later use and there fore must always be
generated on-site by an ozone generator. The two main principles of ozone generation are UV-light and corona
discharge. While the corona-discharge method is most common because of its ability to generate very high
concentrations (up to 50%), it is inappropriate for calibration needs since the level of fine control over the O3
concentration is poor. Also, the corona discharge method produces a small amount of NO2 as a byproduct,
which also may be undesirable in a calibration application
The UV-light method is most feasible in calibration application where production of low, accurate concentrations
of ozone desired. This method mimics the radiation method that occurs naturally from the sun in the upper
atmosphere producing the ozone layer. An ultra-violet lamp inside the generator emits a precise wavelength of
UV Light (185 nm). Ambient air] is passed over an ultraviolet lamp, which splits some of the molecular oxygen
(O2) in the gas into individual oxygen atoms which attach to other existing oxygen molecules (O2), forming ozone
(O3).

Figure 9-13: O3 Generator Internal Pneumatics

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