Coefficient of haze

The coefficient of haze (also known as smoke shade) is a measurement of visibility interference in the atmosphere.

One way to measure this is to draw about 1000 cubic feet of air sample through an air filter and obtain the radiation intensity through the filter. The coefficient is then calculated based on the absorbance formula

$COH=-100\log _{10}\left({\frac {I_{1}}{I_{0}}}\right)$

where $I_{1}$ is the radiation (400 nm light) intensity transmitted through the sampled filter, and $I_{0}$ is the radiation intensity transmitted through a clean (control) filter.

Further reading

• Alan D. McNaught and Andrew Wilkinson (1997). "Coefficient of Haze". IUPAC Compendium of Chemical Terminology (PDF) (2nd ed.). International Union of Pure and Applied Chemistry. ISBN 978-0-86542-684-9.
• James P. Lodge (1988). "Continuous Tape Sampling of Coefficient of Haze". Methods of air sampling and analysis (3rd ed.). CRC Press. ISBN 9780873711418.