Research on Low Cost Hydrogen Sulfide Sensor Based on Spectral Absorption
CHEN Shu-wang1, WANG Zhao-zhao1, TANG Dong-lin2
1. Institute of Information Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China
2. Institute of Electrical and Mechanical, Southwest Petroleum University, Chengdu 610500, China
Abstract：Nowadays, the development trend of H2S concentration detection is real-time detection. The method based on spectral absorption principle is one of the development directions. The broadband light source was used to replace the high cost narrow band light source used in the past, so as to reduce the cost of the whole system and improve the practicability of the detection system. Narrow band light can be obtained by Bragg grating filtering for broad band light source. The light wave obtained by this method must be noise and fluctuate. So it was filtered to eliminate the noise and fluctuation of part of the system, and then the light beam splitter was used to make the difference between the detected optical path and the reference optical path. The differential signal not only eliminated part of the system noise and fluctuation, but also eliminated fundamental wave component. The useful signal value was relatively large, and the signal-to-noise ratio was increased. The second harmonic signal was deduced by mathematical analysis. The second harmonic was observed by SIMILINK simulation. Different concentrations of H2S gas would have different output signals, and the concentration of gas would be obtained. The advantages of the dual optical path difference method, harmonic detection technique and narrow band filtering technology were that the cost was reduced, the signal-to-noise ratio was increased, and the detection capability of the system was improved. The experimental results showed that it was feasible to detect H2S gas concentration by using the dual optical path difference method to extract harmonic signal on the basic of LED broad band light source. This method will reduce the system cost and provide the possibility for large-scale practical application.
陈书旺，王昭昭，唐东林. 基于光谱吸收原则的低成本硫化氢传感器研究[J]. 光谱学与光谱分析, 2018, 38(02): 611-615.
CHEN Shu-wang, WANG Zhao-zhao, TANG Dong-lin. Research on Low Cost Hydrogen Sulfide Sensor Based on Spectral Absorption. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(02): 611-615.
