Figure 3.

Absorption spectrum in the range 6638 – 6641 cm⁻¹ for the major absorbing reaction products (ring down time as a function of wavenumber for H₂O₂, H₂O and C₂H₄, absorption cross sections in 20⁻²¹ cm² taken from Staak et al for CH₂O) as well as the spectrum such as observed from the oxidation of n-butane at 638 K and 875 K. CH₄ line at 6640.72 cm⁻¹ al blue dotted line, CH₂O line at 6639.33 cm⁻¹ as green dotted line.