We have developed a complete infrared absorption and tomographic inversion system. The source, a computer-controlled KCl:Li color center laser, is tunable over the 2.45-2.82 mu m range, allowing spectral access to many combustion and incineration products. A fast wavelength-locking algorithm, in conjunction with the laser linewidth of similar to 0.1 cm(-1), ensures line-center measurements for determination of temperature and concentration. The newly developed tomographic inversion method takes maximum advantage of a priori information, and can require only a small number of well-configured line-of-sight measurements to produce accurate reconstructions. Numerical experiments using simulated absorption data to reconstruct both temperature and concentration distributions have been performed. As few as 20 line-of-sight measurements are required to produce high-fidelity reconstructions in these numerical experiments.