Characterization of six clustered methane-air diffusion microflames through spectroscopic and tomographic analysis of CH* and C2* chemiluminescence

•Filtered imaging and emission spectroscopy were applied to clustered microflames.•Tomographic analyses of the CH* images were used to characterize the 3D flame zones.•Flame temperatures were determined from C2* and CH* spectra.•Spatial information from tomography were assigned to the C2* temperatures.•The combination of these two techniques was found a powerful diagnostic tool.