Machinery Lubrication May June 2014 May June 2014 | Page 34

particle sizes, with RDE limited to

percentages. It can find water in all

Including these details is the customer’s

particles less than 8 to 10 microns and

three forms: dissolved, emulsified and

responsibility.

ICP limited to particles less than 3

free. The crackle test and hot-plate test

information, the effectiveness of the

microns. Nevertheless, they are useful

are non-instrument moisture tests for

report will be diminished. Knowing

for providing trend data. Possible

screening before the Karl Fischer

which piece of equipment the oil was

sources of many common elements are

method is used. Possible reasons for a

sampled from affects the ability to

shown in the table on the right.

moisture reading being too high or too

identify

low would include water ingression

measured parameters, especially wear

Without

potential

The best way to monitor this type of

this

sources

of

the

particles.

For

example,

the

data is to first determine what is

ELEMENT

expected to be in the oil. An effective oil

Aluminum

Pistons, bearings, pumps, thrust washers

originating piece of

analysis report will provide reference

Antimony

Bearings, grease

equipment can help

data for the new oil so any amounts of

Barium

Rust and oxidation inhibitor additives, grease

associate

additive

Boron

Anti-corrosion additives in coolant, dust, water

wear particles with

Calcium

Detergent/dispersant additives

certain

contaminants. Also, because many

Chromium

Piston rings in internal combustion engines

components.

types of elements should be expected at

Copper

Bearings, brass/bronze alloys, bushings,
thrust washers

lubricant information

certain environments), it is better to

Iron

Shafts, rolling-element bearings, cylinders,
gears, piston rings

baseline for several

analyze trends rather than focus on any

Lead

Bearings, fuel additives, anti-wear additives

parameters, such as

specific measurement of elemental

Lithium

Grease, additives

the expected viscosity

analysis data.

Magnesium

Transmissions, detergent additives

grade,

Molybdenum

Piston rings, electric motors, extreme-pressure
additives

additives and acid/

Nickel

Bearings, valve train, turbine blades

quantity of particles in the oil. Many

Phosphorus

Anti-wear additives, extreme-pressure gear
additives

techniques can be used to assess this

Potassium

Coolant additives

but

data, which is typically reported based

Silver

Bearing cages (plating), gear teeth, shafts

forgotten or illegible

on

Silicon

Dust/dirt, defoamant additiv