Abstract
Absorption spectra of nitric oxide in the
γ(0,0) and
γ(1,0) bands have been measured for hard temperature conditions up to
1700
K
in order to validate a model for the simulation of these two bands. The good agreement between experiments and calculations (relative errors of 2–5% for the
γ(0,0) band and 10–15% for the
γ(1,0) band) consolidates the two important assumptions concerning the intermediate Hund's case between (a) and (b) for the X
2
Π state of the
γ(0,0) and
γ(1,0) absorption bands and the use of collisional broadening parameters of
γ(0,0) to simulate the
γ(1,0) band. Using this simulation, a study of the Beer–Lambert law behavior at high temperature has been carried out. With the instrument resolution used for these experiments, it was shown that a correction of the Beer–Lambert law is necessary. To apply this technique for the measurements of NO concentrations inside the combustion chamber of an optical SI engine, a new formulation of the Beer–Lambert law has been introduced, since the modified form proposed in the literature is no longer applicable in the total column range of interest.