Abstract: A technology of infrared spectroscopy diagnoses is introduced for the flame temperature and species concentration of exhaust emission of vehicles. Furthermore, the principle of infrared spectroscopy diagnosis technology is analysed on the basis of the theory of the exponential wide – band model of spectral radition – absorption of gas melecules, and a practical calculating method is given. Finally, an infrared spectroscopy diagnosis system has been established, and the flame temperature and species concentration are measured. The experimental results shows that not only the system can achieve the aim to synchronously measure flame temperature and species concentration, but it has the characteristics of high diagnostic accuracy and quick diagnosis.

Key words: Flame temperature, Infrared spectroscopy diagnosis, Species concentration