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The content of dissolved furfural in oil is an important feature to determine the aging status of transformer insulation. Microfluidic chips are experimental devices that integrate chemical and biological analytical processes, including the synthesis, reaction, separation and detection onto one single microchip and complete the analysis. Moreover, Raman spectrum detection method of furfural in transformer oil based on microfluidic chip has very high sensitivity that could be easily used for monitoring environmental pollutants and biological analysis of samples. In this paper, a microfluidic chip has been designed. The intensity variation of the Raman characteristic peak of furfural reflects the concentration variation of furfural in oil. A direct measurement method of furfural Raman spectroscopy in oil based on microfluidic was established. The microfluidic Raman detection was carried out with deionized water as the dispersed phase, and the lowest concentration of furfural detected was 1.38 mg/L. It could be proved that the feasibility of microfluidic technology for in-situ detection of furfural Raman spectroscopy in oil, which laid the foundation for subsequent research.

As the insulating medium, sulfur hexafluoride (SF 6 ) is widely applied in gas insulation equipment. Over longterm operation, the solid insulation of the equipment is damaged by PD, causing it to react with SF 6 to generate COS and CF 4 which are critical SF 6 decomposition products inside the equipment. The detection of these two SF 6 decomposition products can help in assessment of the type and severity of insulation defects. Compared to the absorption spectroscopy and photoacoustic spectroscopy, FERS can using a single wavelength laser to simultaneously achieve the high sensitivity detection of mixture gases. In this paper, a highly sensitive SF 6 decomposition based on fiber-enhanced Raman spectroscopy is built up. The Raman spectroscopy of COS and CF 4 was acquired. The characteristic peak of COS at 859 cm−1 and that of CF 4 at 909 cm−1 were observed respectively. We study the relationship between laser power, pressure of fiber core and Raman scattering intensity, experimentally. The Raman scattering intensity is linear related to laser power and pressure. The response time of FERS which includes the filling time and evacuating time. was also examined. The filling time of the fiber is defined as the point when the intensity of the Raman peak does not change. FERS is promising to achieve the online monitoring technique to detect the SF 6 decomposition components with highly selective and sensitive.