Jesper Vinther – oil and grease analysis advisor
Jesper Vinther is Managing Director and Partner of TriboTech ApS, a consulting engineering firm in Aarhus, Denmark. He holds a PhD, is a Certified Lubrication Specialist (CLS) and chairs Danish Standards committee S-510. He advises owners of transformers, wind turbines and industrial plant on what their oil and grease analyses show and what to do about it.
Where I come in
Our partner laboratories run the analyses. I am your sounding board and advisor from the moment you plan the programme until you have acted on the recommendation.
- The analysis programme. We set it up for your asset, fluid and operating conditions: which analyses, how often, and against which limits.
- Sampling. A result is never better than the sample behind it. We provide sampling guidance and, by agreement, take the samples and train your staff on site.
- Interpretation. I assess DGA and oil properties against the relevant IEC standards and read the result against the asset's history and operating conditions.
- The recommendation. You get a written recommendation with standard references, in the report format we have agreed with you.
- The larger decisions. Remaining life, regeneration, retrofill and disposal, and expert-witness assignments. During regeneration we help with ongoing measurements of the oil properties, so treatment can be steered by when the agreed criteria are met.
Scope and price are agreed in writing before work starts.
Areas of expertise
- Transformer fluids: DGA and oil properties in mineral oil, natural and synthetic ester, and silicone
- Sampling of oil and grease according to the Theory of Sampling
- Grease in wind turbine bearings: grease analysis for early detection of bearing failure
- Gear and hydraulic oil: additives, particle counting, elemental analysis and viscosity
- Treatment and documentation of transformer oil: drying, regeneration and contaminants such as PCB
- Tribology: lubrication, friction and wear
Education and credentials
- PhD, Nanotechnology, Aarhus University (2010–2014)
- MSc Eng (cand.polyt.), Process Engineering, Aarhus University (2009–2012)
- BSc, Process Engineering, Aarhus University (2006–2009)
- Studies in electrical and electronic engineering, Aarhus University (2015–2017)
- Visiting researcher at Caltech (2013), DTU Danchip and University College Cork (2009)
- Certified Lubrication Specialist (CLS), Society of Tribologists and Lubrication Engineers (STLE) – verify on Credly
- Trained in the Theory of Sampling under Kim H. Esbensen
- Peer-reviewed papers in journals including Nature Nanotechnology, JACS, Advanced Science, Langmuir and Small
- Co-inventor on patent application WO/2020/173822, Detection and quantification of small molecules
S-510 and CIGRE – what it means for you
I chair Danish Standards committee S-510, Væsker til elektroteknisk anvendelse (fluids for electrotechnical applications). The committee follows the European committee CLC/SR 10 and the international committee IEC/TC 10 Fluids for Electrotechnical Applications. IEC/TC 10 prepares, among others, IEC 60422 on supervision and maintenance of mineral insulating oils, IEC 60599 on interpreting dissolved and free gas analysis, and IEC 63585 on DGA in natural and synthetic esters.
For you, this means I follow the work on the IEC standards for insulating liquids that many oil programmes rest on. When a new edition is published, we can go through what it changes for your limits and sampling intervals.
I am also a member of CIGRE. Several of the methods we use rest on CIGRE publications; the Duval Pentagons in our tools, for example, follow the corrected coordinates in CIGRE ICTRAM06-2023.
Articles
Articles on tribotech.dk credited to me as author, for which I hold editorial responsibility.
DGA and fault diagnosis
- Navigating the DGA Maze: A Practical Comparison of IEC, IEEE, and CIGRE Standards
- Which Duval Method Should You Use? Triangles, Pentagons and the Right Choice for Your Fluid
- How Duval diagrams are constructed: ternary geometry, pentagon centroids, and zone vertices
- Inside Duval Triangle 1 and Pentagon 1 — coordinates, zones, and live diagnostics
- When the Fluid Changes the Diagnosis: DGA Across Mineral Oil, Ester and Silicone
- DGA in Load Tap Changers: Don't Read the Sample Like the Main Tank
- Thermodynamic DGA: Gibbs Energy, Fault-Energy Indices, and Why We Don't Use Them as Field Diagnostics
Transformer oil: properties and condition
- What Your Transformer Oil Is Trying to Tell You
- Interfacial Tension: The Most Underrated Test in Your Transformer Oil Programme
- Breakdown Voltage: Why the Method — Not the Oil — Defines the Number
- Dissipation Factor: The Oil Sample's Tan Delta Is Not the Transformer's
- Why Your ppm Water Number Lies — and What %RS Tells You Instead
- Where the Water Actually Is — Oil, Paper, and the Ester Difference
- Rethinking 'End-of-Life': Is a Low DP Score Really a Death Sentence for Your Transformer?
- Which Table Applies? Acceptance, After Filling, and In-Service Limits for Insulating Fluids
- Technical Whitepaper: Corrosive Sulfur in Transformer Oil
- Transformer Oils: Chemistry, Performance and Sustainable Alternatives
- Fire Point and the Less-Flammable Ester Transformer
- Is Silicone Transformer Oil a PFAS? No — and Here Is the Test That Proves It
Treatment and documentation
- Drying Out a Wet Transformer: What It Buys You, and What It Doesn't
- Transformer Oil Regeneration: It Restores the Oil, Not the Transformer
- PCB in Transformer Oil: The Removal Deadline Has Passed — What the 50 mg/kg Line Means Now
- Documenting transformer oil contaminants: what owners must show in 2026 and beyond
Sampling
Lubricating oil, hydraulics and particles
- Counting Particles: PAMAS, Microscopes and Mesh Filters — Why One Number Is Never Enough
- ICP Elemental Analysis: What It Sees, What It Misses, and Why That Matters
- Gear Oil Additives: What Oil Analysis Actually Sees
- Hydraulic Oil Condition Monitoring: Additive Depletion and Particle Count First
- RULER and Antioxidant Depletion: the Earliest Warning Your Oil Will Give You
- Viscosity and the Viscosity Index: what the numbers mean, and what they don't
Contact
Call or write if you want to discuss an asset or an analysis programme.
- Phone: +45 60 76 97 45
- Email: jvinther@tribotech.dk
Hans Møller, Market Director and Partner, also advises on all our services.