In the combustion process, the nitric oxide (NO) concentration and temperature are considered to be highly related to the combustion efficiency. Currently, ultraviolet differential absorption optical spectroscopy (UV-DOAS) has become an ideal method for NO analysis due to its strong absorption characteristics in the UV spectral regime. However, since temperature and concentration have similar effects and complex correspondences on intensity, it is a challenge to achieve dual-indicator sensing of NO at this time. In this paper, we first report a system based on UV-DOAS that allows simultaneous detection of NO temperature and concentration. Specifically, NO temperature was acquired by spectral blueshift, and then, concentration could be calculated based on Gaussian spectral reconstruction combined with the dual parametric surface. First, the mechanism of the temperature-induced blueshift for the NO spectrum was explained based on the energy level distribution theory. On this basis, the relationship between blueshift and temperature has been established based on multipeak spectral autocorrelation algorithm. Second, we introduced a Gaussian spectral reconstruction method based on the mapping domain transformation to improve the data quality. Then, the dual parametric surface about NO temperature and concentration was constructed using the reconstructed optical parameter. After the temperature has been acquired using the blueshift, the NO concentration can also be calculated. The test results indicated that the mean relative error for NO temperature and concentration detection was 1.86 and 2.55% in the ranges 295.15–773.15 K and 0–50 ppm, respectively. Meanwhile, this system exhibited excellent long-term stability with a detection limit of 22.5 ppb∗m.

中文翻译：

---

一种新的光学分析系统，用于在线测量燃烧过程中的 NO 温度和浓度


在燃烧过程中，一氧化氮 （NO） 浓度和温度被认为与燃烧效率高度相关。目前，紫外差分吸收光谱法 （UV-DOAS） 因其在紫外光谱范围内具有很强的吸收特性而成为 NO 分析的理想方法。然而，由于温度和浓度对强度的影响相似且对应关系复杂，因此此时实现 NO 的双指示器感应是一项挑战。在本文中，我们首先报道了一种基于 UV-DOAS 的系统，该系统可以同时检测 NO 温度和浓度。具体来说，通过光谱蓝移获取 NO 温度，然后基于高斯光谱重建结合双参数表面计算浓度。首先，基于能级分布理论解释了 NO 光谱温度诱导蓝移的机制。在此基础上，基于多峰谱自相关算法建立了蓝移与温度的关系。其次，我们引入了一种基于映射域变换的高斯谱重建方法，以提高数据质量。然后，利用重构的光学参数构建关于 NO 温度和浓度的双参数表面。使用 blueshift 采集温度后，还可以计算 NO 浓度。测试结果表明，在 295.15–773.15 K 和 0–50 ppm 范围内，NO 温度和浓度检测的平均相对误差分别为 1.86% 和 2.55%。同时，该系统表现出优异的长期稳定性，检出限为 22.5 ppb∗m。