Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523, USA.
Sensors (Basel). 2023 May 23;23(11):4989. doi: 10.3390/s23114989.
We present a novel sensing approach for ambient ozone detection based on deep-ultraviolet (DUV) cavity-enhanced absorption spectroscopy (CEAS) using a laser driven light source (LDLS). The LDLS has broadband spectral output which, with filtering, provides illumination between 230-280 nm. The lamp light is coupled to an optical cavity formed from a pair of high-reflectivity (R0.99) mirrors to yield an effective path length of 58 m. The CEAS signal is detected with a UV spectrometer at the cavity output and spectra are fitted to yield the ozone concentration. We find a good sensor accuracy of <2% error and sensor precision of 0.3 ppb (for measurement times of ~5 s). The small-volume (<0.1 L) optical cavity is amenable to a fast response with a sensor (10-90%) response time of ~0.5 s. Demonstrative sampling of outdoor air is also shown with favorable agreement against a reference analyzer. The DUV-CEAS sensor compares favorably against other ozone detection instruments and may be particularly useful for ground-level sampling including that from mobile platforms. The sensor development work presented here can also inform of the possibilities of DUV-CEAS with LDLSs for the detection of other ambient species including volatile organic compounds.
我们提出了一种基于深紫外（DUV）腔增强吸收光谱（CEAS）的新型环境臭氧检测传感方法，该方法使用激光驱动光源（LDLS）。LDLS 具有宽带光谱输出，经过滤波后可提供 230-280nm 之间的照明。灯的光线与一对高反射率（R0.99）的镜子形成的光学腔耦合，从而产生约 58m 的有效光程。腔输出处的紫外光谱仪检测 CEAS 信号，并对光谱进行拟合以得出臭氧浓度。我们发现传感器的精度误差小于2%，而精度约为 0.3ppb（测量时间约为 5 秒）。小体积（<~0.1L）的光学腔具有快速响应的能力，传感器（10-90%）的响应时间约为 0.5 秒。还对户外空气进行了示范采样，与参考分析仪的结果吻合良好。DUV-CEAS 传感器与其他臭氧检测仪器相比具有优势，对于包括来自移动平台的地面采样可能特别有用。这里提出的传感器开发工作也可以为使用 LDLS 进行其他环境物种（包括挥发性有机化合物）检测的 DUV-CEAS 提供信息。
