Open path Differential Optical Absorption Spectrometer (DOAS)

Funded through the Department of Science and Technology-PCASTRD grant (2008-present), the Differential Optical Absorption Spectrometer (DOAS) an instrument under development with the Air Quality Dynamics group.

DOAS is used for measuring air pollution concentration. DOAS transmits ultraviolet light through the atmosphere, with the absorption signatures of various gases in the path of the light beam as a means to analyze the pollution rate. Among the gases that were tested on this device are sulphur dioxide (SO2) and ozone (O3).

Currently, an undergraduate student from the Physics Department is working on measuring nitrogen dioxide (NO2) with this instrument. The AQD also plans to test it on BTX or benzene, toluene and xylene, or the traces found on gasoline emissions.