Diode laser measurement of H₂O, CO₂, and temperature in gas turbine exhaust through the application of wavelength modulation spectroscopy

Tunable Diode Laser Absorption Spectroscopy (TDLAS) provides an accurate, fast, and non-intrusive solution for species and temperature measurement. The application of this technology to measure temperature, H₂O, and CO₂ content from an industrial gas turbine has been demonstrated by this research. The multi-gas sensor system, consisting of inexpensive commercially available tunable diode lasers used in the telecommunications industry, uses Wavelength Modulation Spectroscopy (WMS) to quantify path- averaged temperature and concentrations. H₂O and CO₂ spectroscopic information was first gathered in the laboratory and then the system was packaged for field use. The work culminated in an eight-day test in April 2006 where actual stationary gas turbine emissions data were captured. The results demonstrate the capability for measurement of temperature, H₂O, and CO₂ in an industrial environment using two tunable diode laser