Ultra-compact TDLAS humidity measurement cell with advanced signal processing
Ultra-compact TDLAS humidity measurement cell with advanced signal processing
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DOI：
10.1007/s00340-013-5599-7
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发表时间：
2014-05
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影响因子：
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通讯作者：
A. Hartmann;R. Strzoda;R. Schrobenhauser;R. Weigel
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文献类型：
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作者：
A. Hartmann;R. Strzoda;R. Schrobenhauser;R. Weigel
在本文中，提出了使用超紧凑测量单元进行可调谐二极管激光吸收光谱湿度测量。光路长度为 2 厘米。该系统使用 1.854 μm 的垂直腔表面发射激光器。湿度分辨率的主要限制因素不是噪声，而是反射表面产生的干涉条纹。除了系统设置之外，还描述了一种基于吸收线的傅立叶域分析来消除这些条纹的新颖抑制方法。与其他条纹抑制方法相比，该方法能够处理自由光谱范围在吸收线半宽度范围内的条纹。所展示的电池可实现的湿度分辨率在室温下低于 0.25% 相对湿度。
In this paper, tunable diode laser absorption spectroscopy humidity measurements with an ultra-compact measurement cell are presented. The optical path length is 2 cm. The system uses a vertical cavity surface emitting laser at 1.854 μm. The main limiting factor of the humidity resolution is not the noise but interference fringes produced by reflecting surfaces. Next to the system setup, a novel rejection method to eliminate these fringes, based on Fourier domain analysis of the absorption line, is described. In contrast to other fringe rejection methods, the presented method is able to handle fringes, whose free spectral range is in the range of the half width of the absorption line. The achievable humidity resolution for the presented cell is below 0.25 % relative humidity at room temperature.