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Unified diagnostic dashboard for all Duval Pentagon methods
5-gas analysis for power transformers, implementing the Duval Pentagon 1 and 2 methods described in IEEE Std C57.104-2019 Annex D with the corrected coordinates and centroid calculation of CIGRE ICTRAM06-2023.
Coordinate convention: the published sources for Pentagon 1–2 zone vertices disagree on some coordinates (Duval & Lamarre 2014; IEEE C57.104-2019 / CIGRE TB 771:2019; CIGRE ICTRAM06-2023). This tool follows CIGRE ICTRAM06-2023, the method authors’ corrected coordinate set. The full difference between the published conventions moves about 0.30 % of the reachable diagnostic area (Pentagon 1: 0.306 %, Pentagon 2: 0.300 %).
TriboTech's Duval Pentagon dashboard provides all five Duval pentagon variants with support for alternative fluids. Pentagon 3 covers four ester fluid types (rapeseed, soybean, sunflower and synthetic ester); Pentagon 4 relabels its thermal zones as O, C and T3-H, and Pentagon 4b adds the arcing-in-paper sub-zones D1-P and D2-P.
Implements the published zone geometry and calculation procedures of the 5-gas DPM method, following CIGRE ICTRAM06-2023
Rapeseed, Soybean, Sunflower natural esters plus Synthetic Ester (Midel 7131)
Pentagon 2, 4, 4b provide detailed thermal fault classification
The tools are calculation tools made available free of charge by TriboTech ApS as part of the professional communication of its engineering consultancy. The tools perform a calculation based on the values entered and the published methods identified. They do not constitute an examination of an asset, a diagnosis, or advice on any specific asset. The tools have no knowledge of the asset's design, history, loading or operating conditions, and a result cannot therefore serve on its own as the basis for a technical or operational decision. A result is an indication, not a diagnosis. Use of the tools does not create a client relationship and does not create an advisory relationship. TriboTech ApS provides advisory services only under a concluded framework agreement, and no advisory liability is assumed for the use of results from the tools outside such an agreement. Any decision taken on the basis of a result — including a decision not to act — is taken by the user on the user's own professional judgement and at the user's own risk. As CIGRE itself puts it: "Actual actions on the equipment are the sole responsibility of engineers in charge of the transformers" (CIGRE Technical Brochure 771, 2019, section C.8, printed page 54). Each tool states which published methods and which editions the calculation is based on. The standard itself is the authoritative source, and a standard may have been revised since the edition a tool uses.
Method implementation — The calculation behind this tool is versioned. When a correction changes the result the tool gives for the same input, the version below changes with it. Version 1.5 · 08-09-2026. What changed, and when
Terms
There is no single Duval method. Which triangle or pentagon to use is decided by fluid, then equipment, then the question you are answering — a practical selection guide.
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How the two most-used graphical DGA methods actually work. Step-by-step ternary and pentagon arithmetic, the zone boundaries that came from inspected transformer cases, and when each diagram earns its place on a real diagnosis.
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The geometry behind the two most-used graphical DGA methods — barycentric projection for Triangle 1 and an area-weighted polygon centroid for Pentagon 1. Step-by-step derivations, worked examples, and the deliberate asymmetry in how the zones are defined.
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Learn how to integrate IEC 60599, IEEE C57.104, and CIGRE TB 771 into a unified DGA interpretation workflow. Master the triage, quick check, and deep diagnosis methodology used by senior diagnosticians.
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