基于DLAS技术的现场在线气体浓度分析仪半导体激光吸收光谱气体浓度分析仪器可现场在线分析工业过程气体浓度，具有无需采样预处理、响应速度快、不受背景气体和粉尘影响以及恶劣工业环境适应能力强等突出优势。在介绍调制吸收光谱基本原理的基础上详细介绍了仪器的性能特点和组成结构。实验显示该仪器具有小于±１％的线性误差和长时间稳定性。现场应用证实了该仪器优越的工业环境适应性和高可靠性。An in situ gas concentration analyzer based on diode-laser absorption spectroscopy (DLAS) has been developed for gas sensing in industrial processes with fast time response, immunity to background gas and dust, and exceptional harsh-environment suitability. After introducing the principle of modulation spectroscopy, this paper describes the features and configuration of the analyzer. Laboratory and field experiments demonstrate that the analyzer has less than 1% linearity and long-term stability, and high reliability even in industrial environment.