What is tribology consultancy?

Tribology consultancy involves expert analysis and advisory services for lubricating oils, grease, transformer oil, and coolants to optimize equipment performance and reliability.

What industries does TriboTech serve?

TriboTech serves TSOs, DSOs, wind farm operators, data centers, solar parks, and industrial operators across Northern Europe.

How quickly can TriboTech respond to emergencies?

TriboTech offers 24/7 emergency support for critical infrastructure with analysis results typically within 48 hours.

Are TriboTech's diagnostic tools free to use?

Yes, all TriboTech diagnostic tools are 100% free to use with no registration required. This includes all 7 Duval Triangles, 5 Pentagon variants, and IEC 60599 ratio analysis. Duval Triangle 1 implements the zone geometry as published in IEEE Std C57.104-2019; Duval Pentagons 1 and 2 implement the zone geometry as published in CIGRE ICTRAM06-2023; and the ratio tool implements the method as published in IEC 60599:2022.

What is the ISO 4406 cleanliness code?

ISO 4406:2021 communicates the solid-particle contamination level of a hydraulic or lubricating fluid as three scale numbers separated by oblique strokes (e.g. 22/18/13). The numbers map cumulative particle counts ≥ 4 µm(c), ≥ 6 µm(c), and ≥ 14 µm(c) per millilitre to a scale defined in Table 1 of the standard.

What does "µm(c)" mean?

The "(c)" suffix denotes calibration per ISO 11171 (or PCM calibration per ISO 21018-3 / 21018-4). It distinguishes automatic-particle-counter (APC) sizes from optical-microscope sizes per ISO 4407, which are reported as 5 µm and 15 µm without the suffix.

How do I read 22/18/13?

Per Clause 4.4.5: more than 20 000 and up to 40 000 particles ≥ 4 µm(c) per mL, more than 1 300 and up to 2 500 ≥ 6 µm(c) per mL, and more than 40 and up to 80 ≥ 14 µm(c) per mL. Each "step" in the scale roughly doubles the population.

What if my particle count is too high to count or too low to be statistically valid?

Per Clauses 4.4.6–4.4.7: "*" replaces the scale number when too many particles are present to count; "—" indicates no requirement to count that channel; and "≥" labels a scale number when fewer than 20 particles were counted in that size range, indicating reduced statistical confidence (Cl. 4.4.7 example: 14/12/≥7). This calculator implements the "≥" label — tick "fewer than 20 particles counted" for a channel and its scale number is printed with the label, and that channel is left out of the cumulative-order plausibility check, because Cl. 4.4.7 allows a labelled scale number to be understated. The "*" and "—" notations are not offered here; enter only channels that were counted.

Where does the data for the calculator come from?

The implementation reproduces Table 1 of ISO 4406:2021 verbatim. Class boundaries use "up to and including" semantics — a count exactly at the upper bound maps to that scale number, not to the next one up. Counts above 2 500 000 / mL are reported as ">28" per the first row of Table 1.

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ISO 4406 Cleanliness Code Classifier

Name: TriboTech ISO 4406 Cleanliness Code Calculator
Author: TriboTech ApS

Convert cumulative particle counts (≥ 4 µm(c), ≥ 6 µm(c), ≥ 14 µm(c) per millilitre) into the ISO 4406:2021 three-number cleanliness code.

Inputs

Particles ≥ 4 µm(c) per mL

Cumulative count per ISO 11171-calibrated APC or PCM.

Fewer than 20 particles counted in this size range

Tick this if the lab counted fewer than 20 particles in the raw data for this channel. Its scale number is then printed with the "≥" label per ISO 4406:2021 Cl. 4.4.7, and the cumulative-order check is relaxed for that channel.

Particles ≥ 6 µm(c) per mL

Cumulative count per ISO 11171-calibrated APC or PCM.

Fewer than 20 particles counted in this size range

Particles ≥ 14 µm(c) per mL

Cumulative count per ISO 11171-calibrated APC or PCM.

Fewer than 20 particles counted in this size range

Result

Enter three cumulative particle counts to compute the cleanliness code.

Terms of use Use of the tools is entirely at the user's own risk. Quality assurance of the calculated result rests with the user. A result is an indication, not a diagnosis.

Worked examples

Standard's reference example (22/18/13)

40 000 / 2 500 / 80 particles per mL (≥4 / ≥6 / ≥14 µm(c)) → 22/18/13

Typical in-service hydraulic oil (18/16/13)

2 500 / 500 / 80 particles per mL (≥4 / ≥6 / ≥14 µm(c)) → 18/16/13 — a common OEM target, but too dirty for servo systems

Contaminated fluid (23/21/17)

80 000 / 20 000 / 1 300 particles per mL (≥4 / ≥6 / ≥14 µm(c)) → 23/21/17

Methodology

Scale numbers are allocated per ISO 4406:2021 Table 1. Each row uses "up to and including" semantics — boundary counts map to the lower scale number. Counts above 2 500 000 / mL are reported as ">28".

About the tools on tribotech.dk

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 calculations behind the tools on this site are versioned. When a correction changes the result a tool gives for the same input, that tool's version changes with it. What changed, and when

Terms

TriboTech ApS

Expert Tribology Consultancy

Inputs

Particles ≥ 4 µm(c) per mL

Cumulative count per ISO 11171-calibrated APC or PCM.

Fewer than 20 particles counted in this size range

Particles ≥ 6 µm(c) per mL

Cumulative count per ISO 11171-calibrated APC or PCM.

Fewer than 20 particles counted in this size range

Particles ≥ 14 µm(c) per mL

Cumulative count per ISO 11171-calibrated APC or PCM.

Fewer than 20 particles counted in this size range

Worked examples

Standard's reference example (22/18/13)

40 000 / 2 500 / 80 particles per mL (≥4 / ≥6 / ≥14 µm(c)) → 22/18/13

Typical in-service hydraulic oil (18/16/13)

2 500 / 500 / 80 particles per mL (≥4 / ≥6 / ≥14 µm(c)) → 18/16/13 — a common OEM target, but too dirty for servo systems

Contaminated fluid (23/21/17)

80 000 / 20 000 / 1 300 particles per mL (≥4 / ≥6 / ≥14 µm(c)) → 23/21/17

About the tools on tribotech.dk

Terms