Question 1

What does the Oil Condition Classifier do?

Accepted Answer

It classifies an in-service insulating liquid against the maintenance standard that governs it — Good/Fair/Poor under IEC 60422, IEC 61203 or IEC 62975, Class I/II/III under IEEE C57.106, acceptable/investigate under IEEE C57.147 and C57.111, or Group 1/2 under IEC 60944. This is the condition half of a fluid diagnosis; the Duval and IEC 60599 tools answer the separate question of whether a fault is active.

Question 2

Why does the parameter list change when I switch standard?

Accepted Answer

Because the parameters are not interchangeable. IEC paths use breakdown voltage per IEC 60156 with a 2.5 mm gap and dissipation factor at 90 °C. IEEE and ASTM paths use electrode-specific breakdown voltage (ASTM D1816 at 1 mm and 2 mm, D877, D3300 impulse) and dissipation factor at 25 °C and 100 °C. Scoring a D1816 result against an IEC 60156 limit — or vice versa — would be wrong, so the tool only ever asks for what the selected standard publishes.

Question 3

What is the difference between the IEC/IEEE and ASTM modes?

Accepted Answer

IEC and IEEE publish in-service condition assessments. ASTM publishes no in-service condition-classification standard for insulating liquids — D3487, D6871 and D4652 are new-fill acceptance specifications for unused liquid. So the ASTM mode is a within-spec / out-of-spec comparison against the delivery specification, it is labelled as such, and it ignores rated voltage and equipment type entirely.

Question 4

How is the overall verdict calculated?

Accepted Answer

Strict worst-of: the single worst parameter band across everything entered, with no weighting between parameters. Rows the standard cannot classify, and TriboTech operational bands, are shown but excluded from the verdict. IEEE C57.106 is the one exception — it publishes one continued-use limit per parameter, and Class I/II/III is an action classification derived over the whole result set: Class I when every limit is met, Class II when only dielectric strength and/or water fail (reconditioning territory), Class III when anything else fails.

Question 5

Where do the limits come from?

Accepted Answer

From a versioned data file in which every single limit carries its standard, table, row and page number. A build test fails if any value lacks that provenance. The values were compiled and render-verified against the source PDFs, then independently reviewed with the PDFs attached. Where a standard publishes no limit — IEEE C57.147 dissipation factor, footnote c — the tool says so instead of substituting a number.

Question 6

Can I treat the result as a diagnosis?

Accepted Answer

No, and the standards say so themselves. IEC 60422:2024 (Clause 9.4.1) states that classification and corrective action "should only be taken after due consideration of the results of all tests, the age and type of equipment", and that "the trend of such results over a period of time is considered essential information when arriving at a final decision". IEEE C57.106-2015 (§4.2) adds that "no single test can be used as the sole criterion", and §4.2.1.1 that it "is not intended that oil be removed from service when a single property limit is exceeded". This page does the standards comparison — one sample against one table. A defensible assessment also weighs trend and rate of change, the parameters against one another and against the DGA, the unit's age, design, duty and history, and its criticality if it fails. That is consulting work, and it is what TriboTech does.

Question 7

Is my data sent to TriboTech?

Accepted Answer

No. All computation runs in your browser. The page does not log, transmit, or persist any measured value.

Further reading

Breakdown Voltage: Why the Method — Not the Oil — Defines the Number

Why Your ppm Water Number Lies — and What %RS Tells You Instead

Interfacial Tension: The Most Underrated Test in Your Transformer Oil Programme

Dissipation Factor: The Oil Sample's Tan Delta Is Not the Transformer's

Further reading

Breakdown Voltage: Why the Method — Not the Oil — Defines the Number

Why Your ppm Water Number Lies — and What %RS Tells You Instead

Interfacial Tension: The Most Underrated Test in Your Transformer Oil Programme

Dissipation Factor: The Oil Sample's Tan Delta Is Not the Transformer's