Absolute CH concentration in flames measured by cavity ring-down spectroscopy

Abstract

Cavity ring-down spectroscopy (CRDS) was used to measure absolute concentration profiles of the CH radical in low-pressure methane/air flames. The Q1(4) rotational line of the C2∑+ ← X2Π band at 315 nm was used for concentration measurements. Very high sensitivity (2 × 1010 cm-3) is demonstrated. The measured profiles are in good agreement with that calculated using the GRI-Mech mechanism. © 1999 Elsevier Science B.V. All rights reserved.