Cavity-enhanced Raman Spectroscopy for Simultaneous Detection of Characteristic Dissolved Gases in Oil

Abstract-The accurate detection of dissolved gas in oil is the key to realize the operation state evaluation of Oil-immersed power transformers. Raman spectroscopy, as a spectral gas sensing method, has the advantages of no consumption of samples and simultaneous detection of multicomponent gas. In this paper, a linear cavity enhanced Raman spectroscopy detection platform based on PDH is designed and developed. Intracavity powers of $300\mathrm{~W}$ are generated from $300\mathrm{~mW}$ of incident laser power, corresponding to a buildup factor of 1000. The Raman spectrum of air was analyzed and obtained. The CO
2
and CO are also detected in the environment. Two weak Raman peaks are observed at 1387 and $2143\mathrm{~cm}^{-1}$ respectively. The hydrocarbon of dissolved gas in oil are mainly analyzed. With $60\mathrm{~s}$ exposure time and $1\mathrm{~atm}$ total pressure, the detection limits of $\mathrm{CH}_{4},\mathrm{C}_{2}\mathrm{H}_{6},\mathrm{C}_{2}\mathrm{H}_{4}$ are $2.63,6.85$ and 2.92 respectively.