Flame emission spectroscopy emerged as a technique for gas flow temperature monitoring in combustion chambers. The measurement could be based on soot emission or C 2∗ electronic vibrational–rotational lines. However, during the exploitation of a gas turbine, it is hard to resolve emission spectra sufficiently to differentiate rotational levels whereas soot emission does not provide satisfactory accuracy. This study proposes a method of measuring a gas flow temperature based on the combination of soot emission and C 2∗ electronic-vibrational spectra. C 2∗ vibrational temperatures are obtained with the help of electronic-vibrational lines. The variance between the C 2∗ vibrational temperatures obtained through the use of different emission bands are applied to correct the calculated value of the soot temperature and to find the gas flow temperature. The experimental study has demonstrated that the gas flow temperature in the primary zone of the combustion chamber varies from 2064 to 2318 K, with standard deviations from 0.3% to 1.5% of the measured value.