炉口火焰是在转炉炼钢过程中最重要的对炉内钢水温度和成分含量判定的一个重要依据。将炉口火焰光谱分为两部分频谱：背景光谱和原子发射光谱特征。假设背景光谱光强度补偿了特征原子的受激而产生的自吸或者自蚀光强度损失，基于火焰发射光谱(FES)原理和转炉炼钢过程中的火焰光谱，推导出特征原子光谱和强度与火焰温度之间的关系。结果表明，火焰发射光谱测温法所测得的温度与实际温度的误差能够在理想的范围内。

Flame of basic oxygen furnace is the most important evident in the steel making process. The flame spectrum is divided into the background spectrum and the characteristic atomic emission spectrum. Compared with the figure of the characteristic atomic emission spectrum measured by spectrometer with the Gaussian function, the conclusion shows that the background spectrum can compensate the loss of the light intensity due to the stimulated absorption of characteristic atomic. Based on the flame emission spectrometer (FES) and spectrum in the basic oxygen furnace (BOF′s) flame, a new relationship between the intensity of characteristic atomic spectrum and the temperature of the flame is deduced. The results indicate that the temperature measured by FES is inosculated to the temperature obtained by converter sub-lance comparatively.