1981 Volume 16 Issue 1 Pages 35-43
A chemiluminescent light has been obtained from the reaction of ozone with an oil coated paper filter. The light emission has a gentle spectrum in the wavelength of 400-550 nm, and its intensity is generally strong for lubrication oil such as automotive engine oil. As an application of this phenomenon, a proto-type ozone monitoring system has been made. This ozone monitor is composed of a reaction vessel with an optical window, a detection and sample gas flow systems. The sample gas containing ozone is introduced into the vessel through a glass nozzle, and sprayed on surface of the reactive paper filter. The light generated in the vessel is emitted through the window, and detected by a photomultiplier tube. Its output signals per 10 seconds are continuously measured by a photon counter. To obtain a high and steady sensitivity to ozone concentration, this apparatus was typically operated under the conditions of a sample flow rate and a pressure in the vessel, 1.2 l/min, -300mmHg, respectively.
To standard ozone, the limit of sensitivity represented 0.001 ppm (v/v). The light response varied linearly with ozone concentration over the range of 0-0.19 ppm, its change to 0.15 ppm ozone was within ±3% for three months. To atmospheric ozone, the measuring accuracy resulted in nearly 0.01 ppm. However, daily ozone concentrations by this ozone minitor were almost in agreement with the results from a conventional chemiluminescence ozone meter using ethylene. Therefore, it can be considered that this new method is the quite satisfactory for its practical use as an atmospheric ozone monitor. In addition, the ozone monitoring system can be used so safely that ozone concentrations are determined without employing combustible ethylene.
