Department of Chemistry, Snow College, Richfield, UT 84701, USA.
Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA.
Sensors (Basel). 2022 Mar 29;22(7):2626. doi: 10.3390/s22072626.
Sulfur dioxide (SO) is an important precursor for the formation of atmospheric sulfate aerosol and acid rain. We present an instrument using Broadband Cavity-Enhanced Absorption Spectroscopy (BBCEAS) for the measurement of SO with a minimum limit of detection of 0.75 ppbv (3-σ) using the spectral range 305.5-312 nm and an averaging time of 5 min. The instrument consists of high-reflectivity mirrors (0.9985 at 310 nm) and a deep UV light source (Light Emitting Diode). The effective absorption path length of the instrument is 610 m with a 0.966 m base length. Published reference absorption cross sections were used to fit and retrieve the SO concentrations and were compared to fluorescence standard measurements for SO. The comparison was well correlated, R = 0.9998 with a correlation slope of 1.04. Interferences for fluorescence measurements were tested and the BBCEAS showed no interference, while ambient measurements responded similarly to standard measurement techniques.
二氧化硫（SO）是大气硫酸盐气溶胶和酸雨形成的重要前体。我们介绍了一种使用宽带腔增强吸收光谱（BBCEAS）的仪器，该仪器可在 305.5-312nm 的光谱范围内使用 5 分钟的平均时间测量 SO，最低检测限为 0.75ppbv（3-σ）。该仪器由高反射率镜子（310nm 时为 0.9985）和深紫外光源（发光二极管）组成。仪器的有效吸收路径长度为 610m，基底长度为 0.966m。使用已发表的参考吸收截面来拟合和反演 SO 浓度，并与 SO 的荧光标准测量进行比较。比较结果相关性很好，R=0.9998，相关斜率为 1.04。对荧光测量的干扰进行了测试，BBCEAS 显示没有干扰，而环境测量对标准测量技术的响应相似。
