Set-up and evaluation of an in situ absorption spectrometer for trace gases and gas-borne particles
M.Sc. Fabian Hagen
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Students of chemical engineering/process engineering (or similar) with interest in experimental work as well as a preference for innovative analytical tools. Knowledge in aerosol or particle technology, physical chemistry and/or applied spectroscopy may help to get started but is not required.
In situ UV-VIS-NIR absorption spectroscopy allows the non-intrusive and time-resolved concentration measurement of trace gases and/or gas-borne particle ensembles. When trace gases and/or aerosol particles pass through a broadband light source with a defined emission spectrum, the molecules and particles leave a fingerprint in the absorption spectrum measured via spectrometer, which in turn allows quantification of their concentration. For specific trace gases, such as SO2, it even seems capable of simultaneously measuring gas phase temperature by sophisticated analysis of the absorption spectra.
The thesis deals with the set-up and evaluation of an in situ absorption spectrometer for trace gases and gas-borne particles. First, the spectrometer has to be set up, the light source must be characterized and finally quantitative concentrations of selected gas phase species as well as aerosol systems have to be analyzed. Second, it needs to be verified whether a temperature determination of gas samples by analysis of the absorption spectrum might be realized. Finally, the system is to be adapted in such a way that the detection of the elemental composition of gas-borne particles on the (sub-) micrometer scale (preferably of iron and its oxides) is possible.
Prof. Dr.-Ing. Dimosthenis Trimis