Abstract

Fourier-transform (FT) spectroscopy is used to determine the concentrations and temperature profiles of different species in 20-Torr flames. Some of the species that have been analyzed are CO in a C₂H₄/O₂/Ar flame and NO and N₂O in a H₂/N₂O/Ar flame. Temperature profiles are calculated by using Boltzmann rotational distributions of these species. The concentration profiles are determined by two different methods. In method one, the absolute concentrations are determined by measuring the integrated absorbance of a vibrational band. In method two, the relative concentrations are determined by measuring the intensity of the rotational line that is least sensitive to temperature change. Species such as CO are more difficult to measure since they are combustion products that diffuse throughout the chamber, resulting in absorption due to both hot and cold gases.

© 1992 Optical Society of America