24 hour
emergency oil
testing service

Range of Oil Analysis Services

Transoil Labortaory provides a comprehensive service for the analysis of insulating oil and othere insulating fluids such as Silicone and Midel 7131.


Monitoring and maintaining insulating oil/fluid quality and the integrity ofa  trasnformer are essential in ensuring reliable plant operation.


The Standard analysis process:


Oil/Fluid Condition


Acidity - Electric Strength - water Content - Appearance - Colour - Sediment - Odour - Fibres - Resistivity - Dielectric Dissipation Factor - Corrosive Sulphur - Inter Facial Tension (IFT).




Polychlorinated Biphenyls (P.C.B)

Wear Minerals


Polychlorinated Terphenyls (P.C.T)



Transformer Condition Monitoring


Dissolved Gas Analysis (DGA) - Furans Analysis


Following the above analyses a detailed diagnostic report is issued with the results and recommendations highlighted.  If further investigation is required into the possible fault condition this will also be reported.  We at Transoil will be on hand to assist you in determining the correct action to take if fault condition is found.




Reliable Performance of mineral insulating oil in an insulating system depends upon certain basis oil characteristics, which can affect the overall performance of the electrical equipment.


Resistivity & Dissipation Factor


These tests are sensitive to the presence of soluble polar contaminants, and products of oil ageing.




Acidity increases as a result of oxidative ageing and is used as a guide in determining when oil should be changed.


Water Content


Water can originate from the atmosphere or be produced by the deterioration of insulating materials, and in general remains in solution.  The solubility of water in oil increases with temperature and acidity.  In a transformer the total mass of water is in the cellulose insulation system and the oil.  The bulk of the water being present in the cellulose.  Small changes in temperature significantly change the water content of the oil but only slightly that of the cellulose.  In the case of transformers therefore the oil temperature at sampling is critical.


Electric Strength


Electric strength is a measure of the ability of oil to withstand electric stress.  Clean dry oil is confirmed with a high electric strength.  High water, solid particles and fibres in combination reduce electric strength values significantly.




Not a critical property, but gives a guide to the general condition of the oil.






Haziness may indicate the presence of free water, insoluble sludge, carbon or other contaminates.




An acid odour confirms the oil to be at an advanced stage of ageing.  Hydrocarbon gases require the analysis of Dissolved gases.




Visual examination, looking for the presence of oil oxidation products, colloidal carbon, bitumen and general debris.  The presence of sediment may deteriorate the electrical properties of the oil.




Visual examination through polarised light.  The excessive presence of fibres and moisture, significantly lower the electric strength.