Principles: |
Ozone has a strong absorption spectrum at the ultraviolet band (near 254nm) , so the ozone concentration is measured by the absorption photometry. Non dispersive ultraviolet ray is exposed to sample cell from Hg lamp. By the difference of ozone concentration, the absorbed light intencity differs. The ozone concentration is derived from Lambert-Beers Law. I = I0 exp(-eLC) I : Absorped light intensity (measure) I0 : Unabsorbed light intensity (blank) e : Molecular absorption coefficiency L : Light pass lenght C : Ozone concentration |