A day in the life of an oil sample (Crackle Test)

A Day In The Life Of An Oil Sample.

Have you ever wondered what happens to your oil after you’ve sent it to our laboratory? In this blog series, we will be discussing some of the tests your oil may be put through and how they give us an insight into the health of your equipment.

Hotplate Crackle Test.

If your oil snaps, crackles or pops when heated, it could mean there is an abnormal level of water contaminating your lubricant.

crackletest A day in the life of an oil sample (Crackle Test)

How it works.

Every oil sample that comes to the laboratory is given a hotplate crackle test as standard. A small amount of oil is dropped onto a hotplate heated to at least 160’C, but typically over 200’C to make sure it truly boils vigorously. A sample without any detectable water (<0.1%) will not bubble or make a noise. If the sample bubbles, spits, crackles or pops like your favourite breakfast cereal, then an abnormal amount of water is present. Further testing such as a calcium hydride or Karl Fisher water titration will be required to determine how much water is present and whether it is free-standing or dissolved water.


What does it tell us?

The crackle test clearly shows any oil samples that have a significant level of water in them. This allows the lab technicians to separate out any samples that require further water testing (see our other water articles to learn more about these tests). Low levels of water in certain oils are completely normal due to condensation and detergent additives or as they are designed to be fire resistant e.g. a type of hydraulic oil known as a water-glycol / water emulsion. The knowledge of our diagnosticians allows them to see which oil samples contain dangerously abnormal water levels and which are normal for the type of oil.


If you’re interested in learning more about oil analysis, press the contact button below to message a member of the team.