可调谐二极管激光吸收光谱(TDLAS)技术是利用二极管激光器的波长调谐特性，获得被选定的待测气体特征吸收谱线的吸收光谱，从而对待测气体进行定性或定量分析。TDLAS技术与开放式的多次反射池相结合，分别利用二次谐波探测方法和自平衡加波长调制的新型检测方法，测量了酒精喷灯火焰的CO浓度。测量结果表明，自平衡加波长调制的新型检测方法与二次谐波检测方法相比，不仅使检测限提高了16．3倍，还有效地消除了激光器、火焰的光强波动影响，可以应用在燃烧控制及喷焰气体CO浓度测量等多个领域。

Tunable diode laser absorption spectroscopy(TDLAS) is a new method to detect trace-gas qualitatively or quantitatively based on the scan characteristic of the diode laser to obtain the absorption spectroscopy in the characteristic absorption region. With the combination of TDLAS and the open-path multi-pass Herriot cell, using second harmonic detection and the auto-balanced detection with wavelength modulation respectively, the CO concentration of flame of alcohol blowtorch is measured. The result shows that, comparing with second harmonic detection, the new detection method of auto-balanced detection with wavelength modulation not only improves detectability of 16.3 times, but also eliminates impact from light-intensity fluctuation generated by laser and flame effectively, and could be applied for CO concentration monitoring in many fields including combustion control and component measurement of flame.