Testing of Lubricants

Testing of Lubricants 

& its significance 

Hussam Adeni 

Lube.specialist@gmail.com

Testing of lubricants 


Type of lubricants 

Automotive Lubricants 

Industrial lubricants 

Hussam Adeni 




Automotive Lubricants 

• Engine Oils 

• Gear Oils 

• Brake Fluids 

• Coolants 

• Automatic Transmission Fluid 

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Industrial Lubricants 

• Metal working Oils 

• Neat, Soluble, Synthetic, 

• Semi synthetic 

• Metal Deformation 

• Heat Treatment 

• Corrosion Preventives 

• Dewatering Fluids 

• Industrial Cleaners 

• Compressor Oils 

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Industrial Lubricants 

• Hydraulic Fluids 

• Industrial Gear Oils 

• Turbine Oils 

• Refrigeration Oils 

• Greases 

• Rock Drill Oils 

• Electrical Oils 

• Process Oils 

• Ginning Oils 

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Routine Lubricant tests 

Gear Oils 

• Color 

• Condition / Appearance 

• Acidity 

• Water content 

• Wear Metal Analysis (for used Oils) 

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Turbine Oils 

• Color 

• Condition Appearance 

• Acidity 


• Kinematic Viscosity at 40 °C 

• Demulsification value 


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Compressor Oils 

• Color 

• Condition Appearance 

• Acidity 




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Refrigeration Oils 

• Color 

• Pour /Floc point 

• Dielectric strength 

• Acidity 




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Common Lubricant tests 

Appearance 

• Fresh Oil is bright and clear 

• Presence of water or other contaminants make 

the oil hazy / cloudy 

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Density 

IP 160 /ASTM D 1298 

• Expressed as gm/cc 

• Measured at 15° C 

• Specific gravity ( or Relative density) is the 

density of the substance relative to density of 

water 

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Colour 

ASTM D 1500 

• Expressed on scale of 0.0 to 8.0, latter being 

the darkest – Lovibond Colour Comparator. 

• Natural colour of lighter oils pale/yellow or 

darker for heavier (high Vis. Oils) 

• During usage and onset of oxidation, oil is 

darkened by products of combustion 

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Kinematic Viscosity (KV) 

IP 71 / ASTM D 445 

• Viscosity of a liquid is its resistance to flow & 

is directly related/affected by temperature 

• Viscosity decreases with increase in 

temperature & increases with decrease in 

temperature. 

• Kinematic Viscosity (KV) is expressed in 

centistokes (cSt) 

• ISO Viscosity grades KV @ 40° C and 100°C 

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Viscosity Index ( VI) 

IP 226 / ASTM D 2270 

• VI of an oil is calculated from its Kinematic 

viscosities at 40° C and 100°C 

• High VI – Oils exhibit small decrease in KV with 

increase in temperature 

• Low VI - Oils exhibit large decrease in KV with 

increase in temperature. 

• Paraffinic Oils – have high VI’s ( 80 – 100) 

• Naphthenic Oils – have low VI’s ( 0 – 30) 

Hussam Adeni 



Flash Point (COC or PMCC) 

IP 34 / ASTM D 93, IP 36 / ASTM D 92 

• Lowest temperature at which a vapour above 

liquid will ignite when flame is applied 

• Expressed in Degrees Celsius (°C) 

• IP 34 – Pensky Marten Closed Cup (PMCC) 

• IP 36 – Clevland Open Cup ( COC) 

• Decrease on Flash Point – indicates thermal 

cracking of oil 

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Total Base Number (TBN) 

IP 276 / ASTM D 2896 

• Expressed as mgKOH/gm 

• It is the alkaline reserve incorporated into an 

oil to neutralize acid products of combustion 

derived from sulfur in the fuel. 

• TBN decrease result of 

• Oil oxidation 

• Water contamination 

• Fuel contamination 

• TBN depletion can be reduced by oil ‘top up’ 

Hussam Adeni 



Copper Strip corrosion 

IP 154 / ASTM D 130 

• To evaluate corrosive properties of oil. 

• Particular significance to Gear Oils 

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Dielectric Strength 

ASTM D877 ( Up to 230 kV) 

ASTM 1816 ( Higher voltages) 

• Measures resistivity between two electrodes. 

• Particularly for Transformer oils. 

• Dielectric Strength, drops / fails due to 

contamination, dust, dirt, moisture, etc.. 

• Also for refrigeration Oils for hermetically 

sealed compressors 

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Foaming characteristics 

IP 146 / ASTM D 892 

• Generally due to contamination with surface 

active materials. 

• Excessively high flow rates. 

• Depletion of anti foaming additive package 

• May result in cavitation, pressure drop, 

intermittent flow / circulation. 

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Pour point 

IP 15 / ASTM D 97 

• An indicator of the flow properties of oils at 

low temperature. 

• Crystallization of waxy components at low 

temperature restricts the flow of oil an d 

results in oil starvation. 

Hussam Adeni 



Acidity (TAN) 

IP 177:96 / ASTM D 664 

• Expressed as mgKOH/gm 

• Measures - total acidity of the oil i.e. presence 

of strong inorganic and weak organic acids 

• Increase of TAN indicates 

• Hydrolysis of oil 

• Oxidation 

• Contamination 

• High TAN values can lead to problem of 

corrosion. 

Hussam Adeni 



Water content 

IP 356 (KF) / ASTM D 1744 & 4377 

• Measures extend of water contamination 

• In general “no water” should be present in 

lubricating oil ( Max tolerated is 0.2%) 

• Salt water contamination (Marine grades) may be 

traced to cooler leakages, ship’s hull etc.. 

• Common metals in sea water include 

• Sodium 11,000 ppm, Calcium 400 ppm, 

• Magnesium 1,300, Potassium 400 ppm 

Hussam Adeni 



Total insolubles 

IP 316 / ASTM D 893 

• Total amount of extraneous matter which are 

derived from products of combustion 

• Includes burnt lubricating oil and additive ash, 

rust, salt, wear debris and abrasive matter. (IP 

method deploys high RPM centrifuge +10,000 g, preferred for 

dispersant/detergent additives lube oils- ASTM D893 is 600 – 700 g) 

• Viscosity of an oil increase with increase in the 

level of total insolubles. 

• Expressed as % of the quantity of oil. 

Hussam Adeni 


Common Lubricant tests - others 

Additional tests commonly referred to: 

• Thermal stability 

• Detergency 

• Dispersancy 

• Anti wear Tests 

• Timken OK load 

• Four ball wear 

• Grease consistency 

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Special Lubricant tests 

- For used oils 

Conducted on sophisticated equipment 

for premium lubricants 

• Elemental analysis 

• Wear metal analysis (Particle size 0.1 – 1000 

microns) 

• ICP – Inductively Coupled Plasma Spectra photometer 

• Larger, expensive to buy and maintain, good for R&D 

• Atomic absorption Spectra (AAS) 

• Is simpler , smaller & compact 

• Ferrography (Generally larger particles 10 to 1000 micron) 

• Viewed under high powered microscope, biased to Ferric, 

Hussam Adeni 


Special Lubricant tests – 

- Base oils and raw materials 

Conducted on sophisticated equipment 

for premium lubricants 

• Fourier Transform Infra Red Spectroscopy (FITR) 

• Differential Scanning Calorimeter (DSC) 

• Oxidation onset Temperature (OOT) 

• Gel Permeation Chromatography (GCP) 

• Gas Chromatography (GC) 

Hussam Adeni 



– Wear metal analysis – Used oils 

ICP / Atomic Absorption Spectra (AAS) 

Wear metals may include some of the following 

• Aluminum Pistons, Bearings 

• ChromiumCylinder liner, Piston rings etc.. 

• Copper Bearings, Coolers 

• Iron Crankshaft, Gearing, Piston rings 

• Lead Bearings 

• Manganese Steel components 

• Nickel Pistons rings, steel components 

• Silver & Tin Bearings 

• Molybdenum Piston rings 

Hussam Adeni 



Elemental analysis – Used Oils 

ICP / Atomic Absorption Spectra (AAS) 

Elements commonly found in lubricants include 

• Zinc, Phosphorus Anti wear package (ZDDP) 

• Sulphur Base Oil, additives 

• Sulphur Gear Oil additive 

• Magnesium Rust inhibitors 

• Barium Rust inhibitors 

• Silicon Antifoam 

• Calcium, Detergents 

• Magnesium Detergents 

• Boron Dispersants 

Hussam Adeni 


Special Analytical Tests 

FTIR – for Base Oils & raw material 

Fourier Transform Infra red Spectroscopy 

• FTIR generates a spectrum which is then used to 

confirm the presence of a particular bond (Single 

bond, double bond etc..) 

• Used to determine paraffinic, aromatic and 

naphthenic content in mineral oils 

• To identify functional groups like esters, aromatics, 

amide, etc.. 

Hussam Adeni 



- for Base oils and raw materials 

Differential Scanning Calorimeter - DSC 

• Monitoring a particular property of the oil under 

isothermal conditions with time. 

• Thermograms generated by this technique are 

“Finger prints” of the material/ oil. 

• DSC is used to determine OOT (Oxidation onset 

temperature), OIT (Oxidation Induction Time and 

smoke content 

Hussam Adeni 




Oxidation onset Temperature (OOT) 

• Temperature at which oxidation of the oil begins 

under controlled conditions (PDSC cell) 

• Characterized by peak due to heat of the reaction of 

oxidation. 

• Useful in deciding the working range of the oil 

Hussam Adeni 




Gel Permeation Chromatography- GPC 

• Sample passes through a column with liquid where 

various components are absorbed. depending on 

their molecular weight 

• Used to determine molecular weight of polymers by 

comparing with standard polymer of known 

molecular weight 

Hussam Adeni 




Gas Chromatography- GC 

• Sample passes through a column with a carrier gas 

where various components are absorbed depending 

on the temperatures of the column, packing 

materials etc. 

• Used to determine purity and percentage of various 

components present in a mixture. 

• Mainly used for raw material analysis 

Hussam Adeni 


Thank you 

Hussam Adeni

Testing of Lubricants

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