There are several interpretation techniques on transformer oil dissolved gas analyzing results as follows:

1. IEC 60599 Ratios

2. IEEE C67.104, Limits, rates and TDCG

3. Rogers Ratios

4. Kay Gas Method

5. Duval Triangle

6. Trend Analysis

7. New Guidelines for Interpretation of DGA" CIGRE Tast force 15.01.01, Octorbor 1999

8. Companies guidelines

9. More...

Main diagnostic methods:

- IEC ratio codes

- IEEE methods (Dornenburg, Rogers and Key Gases methods)

- Duval Triangle