Shore-based laboratories carry out a wide range of tests, often as per ASTM standards, to determine the condition of lubricating oil (L.O). Common tests include:

1. Viscosity Test –
   • Oil is placed in a calibrated glass tube and submerged in baths at 40°C and 100°C.
   • The time taken for the oil to flow between two marks is measured, and multiplied by a constant to give kinematic viscosity.
2. Flash Point Test –
   • The oil sample is heated in a closed apparatus.
   • An external flame is applied at intervals to find the temperature at which oil vapour ignites.
3. Water Content Test –
   • Conducted by distillation with a water-immiscible solvent.
   • Water separates and is collected in a trap.
4. Acid and Base Number (TAN & TBN) –
   • Determined by titration using solvents and colour indicators.
   • Gives Total Acid Number (TAN) and Total Base Number (TBN).
5. Density Test –
   • Measured using a hydrometer in a temperature-controlled bath.
6. Spectrographic (Spectrochemical/ICP) Analysis –
   • Detects metallic and non-metallic contaminants.
   • Can measure up to 24 elements, even from particles smaller than 5 μm.
   • Results expressed in ppm. Useful for wear-metal analysis and detecting contamination from other oils.
7. Ferromagnetic (Ferrochemical) Analysis –
   • Identifies the amount of ferrous wear particles.
   • Oil sample is thinned and passed through a strong electromagnetic field.
   • Results expressed in ppm; important for monitoring machinery wear.
8. Other Tests (where applicable):
   • Insolubles Test – measures soot, wear particles, and dirt.
   • Dispersancy Test – checks additive ability to keep carbon in suspension.
   • Index of Contamination – measures level of insoluble contamination.

• Details supplied with sample:
  • Type and grade of oil
  • Running hours
  • Name of machinery
  • Ship name and identification number
• Results obtained from analysis:
  • Viscosity, Density, Flash Point, Pour Point, Carbon Residue
  • TAN (Total Acid Number), TBN (Total Base Number)
  • Water content (ppm)
  • Insolubles/contamination levels
  • Metallic wear particles (iron, copper, tin, antimony, etc. in ppm)
  • Presence/absence of additives (to detect contamination or mixing of oils)
  • Assessment of oil condition: fit for further use / requires renewal
  • Historical comparison for trend monitoring
  • Recommendations for corrective action (e.g., purifier adjustment, temperature control, partial/complete renewal).
  Part (c)

  Possible Reasons for Excess of Particles:

  1. Iron –
     • Indicates wear of ferrous components such as gears, chains, sprockets, liners, piston crown undersides.
  2. Copper –
     • Clear sign of bearing wear (from bronze or brass components).
  3. Antimony –
     • Indicates white metal bearing wear (antimony-based alloys).
  4. Tin –
     • Also points to bearing wear, especially of white metal linings.
  5. Silica –
     • Suggests seal ring damage, allowing silica/dust particles to circulate in the oil.