The measurements of monochromatic line-of-sight flame emission and light transmission in the same path having small spatial resolution by using pinhole array were performed in an axisymmetric laminar propane ($C_3H_8$) diffusion flame. The light wavelengthes of 632nm, 800nm and 900nm were used. From these measurements, local point soot radiance (by Kirchhoffs law) and absorption coefficient were reconstructed by tomography. Thus local point soot temperatures and concentrations were obtained.
The reconstructed soot temperature and concentration of local points has no differences between the case of visible range (632nm) and the case of infrared range (800nm and 900nm). In these ranges, the scattering coefficient is much lower than the absorption coefficient. Soot mean temperature over the path was also obtained. This result matches well with local soot temperature in outer region of the flame.
Temperature measurements by fine wire thermocouple with different bead diameters (222μm and 308μm) were performed in the same flame. Rapid insertion technique was used and radiation effect was considered. Radiation correction for the real temperature in the sooting region was carried out and the corrected result was in good agreement with the local soot temperature.
