Oil testing – or if you want to get all technical, oil analysis – is the process of testing the various different types of oil to ensure that it is not contaminated, and is working at a good level of efficiency.
There are various different ways to test oil, each of which is used to detect the presence of various different substances that shouldn’t be present within the oil itself.
Spectrochemical Analysis
This process is an extensive testing procedure that involves using a spectrometer to detect different forms of particles and contaminants that are present within an oil sample.
It’s broken down into three specific categories:
- Wear metals refers to the parts of machinery that may have rubbed away due to friction, and as a result are now present within the oil as microscopic particles. This type of general wear and tear is a very common process in countless types of machinery as wear and tear always occurs, even though most machinery is protected against this with oil film.
- Contaminants can be practically anything that’s been accidentally added to oil. Whether it’s the presence of fuel from car engines or any other form of chemical additive, conducting a spectrochemical analysis on the oil sample will flag up any contaminants that shouldn’t be there.
- Additives refers to chemical compounds that can be added to oil. Testing these ensures that oil has the correct balance and properties, as adding certain chemicals can change the overall type and usefulness of the oil itself.
The spectrochemical analysis is one of the most important parts of testing absolutely any type of oil, and given that there are potentially hundreds of wear metals, contaminants or additives that could be present in oil, this form of testing flags up the presence of contaminants that could have an extremely damaging effect on the overall efficiency of machinery.
Physical Analysis
As well as conducting extensive testing using a spectrometer, many qualified oil testing laboratories also conduct a number of physical tests to further evaluate the oil’s quality.
- Viscosity testing is perhaps one of the most important tests carried out on oil. Since oil is such a complex substance that can be broken down into different properties, maintaining the correct viscosity really is essential.
- Detecting water or moisture inside oil is another vital process. Sometimes carried out via titration and what’s known as the Karl Fischer titration method, flagging up oil that has water content makes sure that the oil you’re using is fully lubricated and not beginning to break down thanks to the damaging aspects of water/moisture.
- Fuel Dilution testing is carried out by gas chromatography and allows the analyst to determine the overall presence of fuels present in engine oil. Since this runs a significant risk of fire/explosion if left untreated, this form of testing ensures that the oil used in vehicles is working at the correct level.
- Glycol detection is used to ensure that a substance known as ethylene glycol has not invaded the oil. This substance generally comes from cooling system leaks, and can be used to not only determine damage to the oil, but also the machinery that the leak has come from.
Infrared Oil Analysis
As well as all these forms of testing, many analysts are now also using infrared light to detect the various irregularities in oil.
By using infrared light on the oil in question, an analyst can measure the presence of different components in oil by studying how different substances absorb the light’s wavelengths.
This is a widely used form of testing that can measure fuel soot, oxidation, nitration, water, glycol, additives and more.
Ferrography
By the use of magnetism, wear metals and contaminants present within the oil can be removed and arranged by size/composition. This process is generally more regularly used for machine maintenance, allowing the surveyor to analyze the amount of wear and tear inside the machinery.
Dielectric Strength
Electrical transformer rely on oil as an insulating property, so when oil is contaminated, this can be a dangerous process that could affect the overall output and safety of a transformer.
Dielectric testing works by passing an electrical current via two electrodes through oil, then waiting to see how long it takes for an arc to form across the gap. This process is affected by contaminants within the oil, so it is a good method of seeing whether transformer oil is still doing the job.
Automated Particle Count
This method uses a complex, special device to analyze the particles inside oil, clearly flagging up any erroneous material that shouldn’t be there.
Why Complete Oil Testing?
As already touched upon, the process of carrying out oil testing is extremely important because it allows you to not only keep machinery running at optimal levels, but also makes sure that the oil you’re using isn’t going to cause damage to your systems because it is full of contaminants.
Since oil acts as an insulating property, it naturally causes friction when used in machinery. The presence of heat also acts as a factor, ultimately upping the friction of the oil, changing the composition of the substance itself and causing machinery parts (even tiny pieces) to eventually wear away and deposit themselves inside the oil.
The presence of these contaminants – as small as they might be – can have a profound effect on the delicate balance of oil. Since different forms of oil are broken down more specifically from crude oil via distillation/boiling methods into their useful components such as petroleum, plastics etc, anything that affects the properties of oil could have a potentially negative effect on the machinery the oil is lubricating.
By performing regular oil testing, a qualified laboratory can analyze oil samples and make sure you’re not working with oil that’s causing more damage than not. For those working with industrial-grade machinery that relies on oil, it really is an essential process.
Written by Barry Atkins at www.tester.co.uk
