This project aimed at quantifying the accuracy of high temperature H 2O vapor absorption thermometry techniques. Toward this end, a novel gas cell was designed for quantitative spectroscopic studies at temperatures up to 2073 K. Using this cell, direct absorption measurements of neat H 2O vapor were demonstrated at temperatures up to 1723 K over the 7326?7812 cm-1 range. The temperature accuracy of a band-shape spectral temperature fitting technique was demonstrated to be within ? 9.2 K using spectra measured in the gas cell at temperatures spanning 950 K to 1723 K. Preliminary studies indicate better accuracy is obtained when inferring temperature from simulation based on BT2 database parameters as opposed to simulations based on parameters from the HITEMP2010 database.
In parallel to the development of the high temperature gas cell, a single-ended sensor based on the collection of back-reflected light was designed and demonstrated using polished and retro-reflective back-reflection surfaces. The sensor was demonstrated in a combustion fired furnace as well as in an HCCI engine. Initial testing with this sensor demonstrates compatibility with absorption thermometry techniques.