Vaisala Optimus OPT100 - Figure 17 Duval Triangles on the DGA Diagnostics Page

DGA Diagnostics is an optional feature and requires a license. Contact Vaisala for
acquiring the license.
Figure 17 Duval triangles on the DGA diagnostics page
DGA Diagnostics page shows the progression of selected data points from the past year
overlaid on top of Duval triangles:
• Triangle 1: Classic Duval triangle for DGA in oil-filled transformers using methane,
ethylene, and acetylene
• Triangle 4: Diagnosis of low-temperature faults in oil-filled transformers using hydrogen,
methane, and ethane
• Triangle 5: Diagnosis of low-temperature faults in oil-filled transformers using methane,
ethylene, and ethane
DGA monitor automatically selects the data points according to criteria described in section
Criteria for data points in DGA diagnostics (page 39). The data points are listed in a table
below the triangles. Clicking a table row highlights the data point in the overlay and displays
the gas ratios as percentages.
3.1.4.1
Criteria for data points in DGA diagnostics
DGA Diagnostics view shows up to 26 data points from the past year. A data point that meets
selection criteria is automatically selected at roughly two week intervals. If less than one year
of data is available, all of the data is used.
The data points are 24 hour average values for the included gases and must meet the
following criteria for each point:
Chapter 3 – User interface
39