15 October 2013 Measurement methods in trace water vapor concentration detection system based on direct absorption spectroscopy
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Proceedings Volume 8924, Fourth Asia Pacific Optical Sensors Conference; 892421 (2013) https://doi.org/10.1117/12.2031728
Event: Asia Pacific Optical Sensors Conference 2013, 2013, Wuhan, China
In trace water vapor direct absorption spectroscopy, the absorption signal is buried in noise and up and downs of the light intensity, an effective signal extraction method is vital. In the basis of double-beam differential absorption, division method in voltage and an approach based on balanced ratiometer detection (BRD) were studied. Voltage division has an excellent stability to temperature variation, mechanical extrusion and fiber bend loss. As to the BRD method, it has an outstanding self-adjusting capability and it can also avoid an excess phase difference caused by current-to-voltage converting circuit, thus this method has a high sensitivity. Furthermore, a so called dual-peak method based on the differential value of two adjacent absorption lines is introduced, the differential value proved has a linear relation with water vapor concentration, and this method provides a way to measure the concentration at high pressure. In addition, the influence of water vapor inside the optical components has been discussed.
© (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
G. P. Lv, G. P. Lv, J. Chang, J. Chang, S. S. Zhang, S. S. Zhang, Q. P. Wang, Q. P. Wang, Y. N. Liu, Y. N. Liu, Z. Liu, Z. Liu, Q. Wang, Q. Wang, W. J. Wang, W. J. Wang, Z. L. Wang, Z. L. Wang, S. Jiang, S. Jiang, C. G. Zhu, C. G. Zhu, W. Wei, W. Wei, "Measurement methods in trace water vapor concentration detection system based on direct absorption spectroscopy", Proc. SPIE 8924, Fourth Asia Pacific Optical Sensors Conference, 892421 (15 October 2013); doi: 10.1117/12.2031728; https://doi.org/10.1117/12.2031728

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