Thursday, May 26, 2016

Dornenburg's Method

The Dornenburg ratio method makes use of the ratios of the concentration of the key gases hydrogen, methane, ethane, ethylene and acetylene. The following ratios are used CH4/H2, C2H2/CH4, C2H4/C2H6 and C2H2/C2H4.
For this method to be a viable diagnostic tool a few criteria have to be met. This in itself is the negative aspect of this diagnosis method as there are more frequent than not “no diagnosis” obtained.

The criteria are such that for the transformer to be considered to have a problem at least one of the key gas concentrations must exceed twice a predetermined limit with at least one of the remaining three key gases exceeding its predetermined limit. There is also a further validity check that at least one of the key gases in each of the four ratios must exceed the predetermined limit for the ratios to be significant. Only then can the combination be compared to the codes. Once this criteria is met the combination of the ratios into a code is established, where each four parameter code has a unique diagnosis that is able to identify
thermal faults, corona discharge and arcing [IEEE C57.104].



Use the following link to the "Analysis" section to get the Dornenburg diagnosis of the oil samples. Enter the oil sample under "Sample 5" to get the diagnosis.

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