In Situ Photoacoustic Detection System for SO2 in High-Pressure SF6 Buffer Gas Using UV LED

Autor: Wei Hu, Kang Li, Tunan Chen, Zongjia Qiu, Guoqiang Zhang
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Sensors, Vol 22, Iss 24, p 9846 (2022)
Druh dokumentu: article
ISSN: 1424-8220
DOI: 10.3390/s22249846
Popis: Sulfur dioxide (SO2) is a key indicator for fault diagnosis in sulfur hexafluoride (SF6) gas-insulated equipment. In this work, an in situ photoacoustic detection system using an ultraviolet (UV) LED light as the excitation source was established to detect SO2 in high-pressure SF6 buffer gas. The selection of the SO2 absorption band is discussed in detail in the UV spectral regions. Based on the result of the spectrum selection, a UV LED with a nominal wavelength of 285 nm and a bandwidth of 13 nm was selected. A photoacoustic cell, as well as a high-pressure sealed gas vessel containing it, were designed to match the output optical beam and to generate a PA signal in the high-pressure SF6 buffer gas. The performance of the proposed system was assessed in terms of linearity and detection limit. An SO2 detection limit (1σ) of 0.17 ppm was achieved. Additionally, a correction method was supplied to solve PA signal derivation induced by pressure fluctuation. The method can reduce the derivation from about 5% to 1% in the confirmation experiment.
Databáze: Directory of Open Access Journals
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