Title :
Comparison of terahertz and infrared spectroscopy for degraded hydrocarbon liquid
Author :
Ogura, Ryuichi ; Noorden, Zulkarnain A. ; Nam, Nguyen Nhat ; Matsumoto, Satoshi
Author_Institution :
Shibaura Inst. of Technol., Tokyo, Japan
Abstract :
Terahertz (THz) spectroscopy has high sensitivity for the interaction between molecules and vibration of large molecules. Besides, it is well known that infrared (IR) spectroscopy can be used to detect the vibration of functional groups. Hence, the comparison of the conventional diagnosis method using IR spectroscopy and THz spectroscopy is expected for more potential diagnosis. In this study, the comparison between THz spectroscopy and IR spectroscopy for deteriorated hydrocarbon liquids has been conducted for the degraded insulating oils. The surveyed samples are pure dodecane and mineral oil. The degraded samples are made by heating in the oxygen atmosphere. In addition, we also measured the breakdown voltage and the volume resistivity to know the states of degraded insulating oil. The experimental results show that oxidation causes spectral changes in the both of THz and IR regions. The spectral change in the IR region is due to carbonyl group and hydroxyl group vibrations. Whereas, in the THz region, the spectral change originates from the modification of intermolecular interaction. The degradation phenomena of the insulating oil contribute to higher carbonyl/hydroxyl content and associated by stronger intermolecular interaction that leads to its lower breakdown voltage.
Keywords :
electric breakdown; infrared spectroscopy; insulating oils; terahertz waves; vibrations; IR spectroscopy; THz spectroscopy; breakdown voltage; carbonyl group; degradation phenomena; degraded hydrocarbon liquid; degraded insulating oil; diagnosis method; dodecane; hydrocarbon liquids; hydroxyl content; hydroxyl group vibrations; infrared spectroscopy; intermolecular interaction; mineral oil; terahertz; vibration; volume resistivity; Conductivity; Degradation; Heating; Oxidation; Spectroscopy; Vibrations; Voltage measurement;
Conference_Titel :
Electrical Insulation and Dielectric Phenomena (CEIDP), 2012 Annual Report Conference on
Conference_Location :
Montreal, QC
Print_ISBN :
978-1-4673-1253-0
Electronic_ISBN :
0084-9162
DOI :
10.1109/CEIDP.2012.6378818