In situ detection and analysis of dissolved furfural in oil based on Raman spectroscopy

Accurate detection of dissolved furfural in transformer oil is one of the keys to judge the aging degree of oil paper insulation equipment. As a non-contact and nondestructive testing method, Raman spectroscopy not only realizes the use of single wavelength laser to detect the dissolved aging features in the insulating oil, but also has the characteristics of fast detection speed and no need for extraction. In this paper, the Raman spectra of insulating oil, furfural and saturated samples are measured, and the Raman characteristic 1706 cm-1 furfural in oil is determined by comparison. The main reasons for the shift of the characteristic peaks were mainly due to the influence of the C=O bonds on the external factors, based on the simulation results. In addition, in situ test of different concentration of furfural solution is carried out, and the function relation between the ration of the peak area (I1615cm-1/ I1706cm-1) and concentration is established. The linear quantitative analysis model is obtained by using the least square method, and the minimum detection concentration can be determined to reach 2.4mg/L. The results show that laser Raman spectroscopy is an effective and convenient method for transformer aging diagnosis, and has great research value.