Machinery Lubrication May June 2014 May June 2014 | Page 31

machine from which the oil sample was
taken. There are three main categories
of

oil

analysis:

fluid

properties,

• Is

the

machine

degrading

oil change

abnormally?

• Whether filter carts have been in use

• Is wear debris produced?
• From which internal component is

contamination and wear debris.

quantity of makeup oil since the last

between oil samples
• Total operating time on the sampled

the wear likely originating?

Fluid Properties

• What is the wear mode and cause?

component since it was purchased

This type of oil analysis focuses on

• How severe is the wear condition?

or overhauled
• Total runtime on the oil since the

identifying the oil’s current physical and

last change

chemical state as well as on defining its

Ultimately, you need to know if any

remaining useful life (RUL). It is

actions should be taken to keep the

• Any other unusual or noteworthy

designed to answer questions such as:

machine healthy and to extend the life

activity involving the machine that

• Does the sample match the specified

of the oil. Oil analysis for machines can

could influence changes to the

be compared to blood analysis for the

lubricant

oil identification?
• Is it the correct oil to use?

human body. When a doctor pulls a

• Are the right additives active?

blood sample, he puts it through a

Oil Analysis Tests

• Have additives been depleted?

lineup of analysis machines, carefully

For a standard piece of equipment

• Has the viscosity shifted from the

studies the results and

expected viscosity? If so, why?

reports his conclusions

• What is the oil’s RUL?

based
education,

on

OIL ANALYSIS
CATEGORY

TESTS

Fluid Properties

Viscosity, Acid/Base Number, FTIR, Elemental
Analysis

Contamination

Particle Counting, Moisture Analysis,
Elemental Analysis

Wear Debris

Ferrous Density, FTIR, Elemental Analysis

his
research

Contamination

and detailed questions

By detecting the presence of destructive

asked to the patient.

contaminants and narrowing down

Likewise,

with

oil

their probable sources (internal or

analysis,

careful

oil

external), oil analysis can help answer

samples are taken, and elaborate

undergoing the normal recommended

questions such as:

machines

results.

oil analysis, the test slate would consist

• Is the oil clean?

Laboratory personnel interpret the data

of “routine” tests. Alternatively, if

• What types of contaminants are in

to the best of their ability, but without

additional testing is needed to answer

crucial details about the machine, a

advanced questions, these would be

diagnosis or prognosis can potentially

considered “exception” tests. Routine

be inaccurate. Some of these important

tests vary based on the originating

details include:

component

the oil?
• Where

are

contaminants

originating?
• Are there signs of other types of

• The

lubricants?

yield

the

test

and

environmental

leakage?

conditions but should almost always

conditions (extreme temperatures,

include tests for viscosity, elemental

high humidity, high vibration, etc.)

• Is there any indication of internal

environmental

(spectrometric)

machine’s

analysis,

moisture

• The originating component (steam

levels, particle counts, Fourier transform

Wear Debris

turbine, pump, etc.), make, model

infrared (FTIR) spectroscopy and acid

This form of oil analysis is about

and oil type currently in use

number. Other tests that are based on

determining

the

presence

and

identification of particles produced as a

• The permanent component ID and

the originating equipment include
analytical ferrography, ferrous density,

exact sample port location

result of mechanical wear, corrosion or

• Proper sampling procedures to

other machine surface degradation. It

confirm a consistently representative

answers a number of questions relating

sample

to wear, including:

demulsibility and base number testing.
The table above shows how tests are

• Occurrences of oil changes or
makeup oil added, as well as the

utilized in each of the three main oil
analysis categories.

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