The characteristics of oxy-methane flames in atmospheric conditions (298 K and 1 bar) were studied in a lab-scale slot burner. As a diagnostic tool, OH*, CH*, and C-2* measurements were used to analyze the flame structure. To estimate the flame stabilization, the flow velocity was varied from u(F) = 7-50 m/s for methane gas and u(OX) = 10-170 m/s for oxygen gas. From the experimental results, the flame stability was enhanced when the slot width became narrower. The flame length increased with increasing fuel quantity, while the lift-off height increased with increase in the fuel jet and oxygen velocity. Using the concept of effective diameter, an empirical formula for flame length was suggested for use in a combustor design. (C) 2012 Elsevier Ltd. All rights reserved.