Determination of the hydrogen diffusion coefficient in transformer oil

The hydrogen diffusion coefficient in transformer oil is determined by optically monitoring the dynamics of the hydrogen bubble dissolution in pure degassed oil. The diffusion coefficient is found to be roughly two orders of magnitude smaller than those determined earlier. This result is of great importance for chromatographic analysis of gases dissolved in transformer oil, since it gives grounds to suspect that hydrogen is not so volatile as implicitly believed in a number of works. Accordingly, the reliability of diagnostic data for high-voltage oil-filled equipment improves.