以可调谐激光二极管光谱技术（TDLAS）技术为核心的气体测量系统以其高精度、响应快和非接触式测量的优点而广泛应用于各种场景之中。本文基于波长调制光谱技术（WMS），以多反气室结构作为区分，搭建了两套适用于不同测量场景的氧气浓度实时监测系统。其中，封闭式测量系统的测量误差为 0.244%，最佳检测限达到 428.46ppm；开放式测量系统的测量误差为 0.19%， 最佳检测限达到 248.545ppm。对封闭式测量系统，在 5%~20%的范围内进行了 氧气浓度的梯度测量，验证了其良好的线性响应特征；由于该系统一般用于对 特定气体进行快速响应监测，因此对人体呼吸气体中的氧气浓度变化进行了测量。开放式测量系统往往用来检测大范围气体浓度变化，因此进行了密闭空 间中的蜡烛燃烧耗氧实验，结合各阶段观测现象对测量数据进行了分析处理；对比了不同数量的蜡烛燃烧时对空间氧气浓度变化的影响；验证了在一定氧 气浓度下，蜡烛耗氧速率与其数量的线性关系。

The gas measurement system based on TDLAS technology is widely used in various scenarios because of its high precision, fast response and non-contact measurement. In this paper, based on wavelength modulation spectroscopy (WMS), two sets of real-time oxygen concentration monitoring systems suitable for different measurement scenarios are built with multipass cell structure as a distinction. The measurement error of the closed measurement system is 0.244%, and the optimal detection limit is 428.46ppm. The measurement error of the open measurement system is 0.19%, and the optimal detection limit is 248.545ppm. For the closed measurement system, the oxygen concentration gradient measurement was carried out in the range of 5% ~20 %, and its good linear response characteristics were verified; since the system is generally used for rapid response monitoring of specific gases, the change of oxygen concentration in human respiratory gas is measured. The open measurement system is often used to detect a wide range of gas concentration changes. Therefore, the oxygen consumption experiment of candle combustion in confined space was carried out, and the measurement data were analyzed and processed in combination with the observation phenomena at each stage. The effects of different numbers of candles on the change of oxygen concentration in space were compared. The linear relationship between the oxygen consumption rate and the number of candles at a certain oxygen concentration was verified.