Characteristics of Tin Oxide Chromatographic Detector for Dissolved Gases Analysis of Transformer Oil

The analysis of dissolved gases in insulation oil is of great significance to transformer status evaluation. In this paper, a chromatographic detector based on the nano-tin oxide fiber as well as a chromatography system is developed. The mechanism of the sensor for detecting six component feature gases (i.e., H-2, CO, CH4, C2H4, C2H6, and C2H2) in transformer oil is expounded, on basis of which the exponent-logarithmic model between conductance and gas concentrations is proposed. Then, the repeatability and accuracy of the nano-tin oxide detectors are tested. The experimental results show that the gases mixture can be separated well by the designed gas chromatography system, and six component gases mixture detection can be realized by the developed detector. Meanwhile, by using the proposed model, high precision of dissolved gas measurement can be achieved, thus the validity of the presented model is verified. Moreover, compared with other chromatographic detectors, i.e., flame ionization detector, the only carrier gas needed for the nano-tin oxide chromatographic detector is the synthetic air, the hardware cost and complexity of system are reduced largely, showing promising applicable value in the engineering practice.