Understand what Oil testing and Analysis is; understand why you need oil testing and analysis, terminology and a basic understanding of report interpretation.
Oil Analysis is the sampling and Laboratory analysis of the lubricants properties; it provides knowledge of lubricants suspended contaminants, and wear debris. Oil Analysis, generally known as OA, is preformed during routine preventative maintenance to provide information on the lubricant and machine condition. By tracking oil analysis sample results, trends can be established which can help eliminate costly repairs and downtime on equipment. OA can be divided into three categories: Oil Properties /Additives, Contaminants and Wear Debris. Oil Analysis was first used by the US railroad industry prior to 1946.
This paper will provide you with the information necessary to review your oil analysis reports and understand what the tests are indicating. The idea is for Techenomics Laboratories to detect indications of a problem in the initial stages of development and then quickly pass that information along to you. To do this, Techenomics analyse the sample using different testing methods, this is dependent on compartment, equipment and oil types, they then interpret the data and provide recommendations requiring actions, there is also a fast visual indicator, and these indicators are coloured smiley faces for quick identification to problem samples. However, these test and recommendations will not succeed in providing you with valued benefits unless you are an active participant in the process. Your participation includes taking the sample from a suitable location and correctly, supplying the Laboratory with the equipment details and lubricant information, supplying virgin oil samples for background reference and feedback on failed compartments. Providing feedback can help the Techenomics report writers to identifying trend patterns for early detection.
Sampling
It is important how you take the sample as well as completing the details on the label, if this is not done correctly, the lab will not be able to provide you with the correct diagnosis of the lubricant and machine condition. You need the correct tooling for the job, a live sample tool or a sample pump, a clean bottle with cap, a label and sample tubing.
All these tools and accessories need to be spotlessly clean as the OA equipment is sensitive and can read particles not visible to the human eye.
When taking the oil sample from the compartment, you need to ensure that the oil is at operating temperature, ensure that there is no pressure in the system to ensure no personal injury occurs, and that you are sampling past the pump and before the filter, if you sample after the filter then you are sampling filtered oil, this will not provide an indicative sample, if you sample from the main reservoir, you need to ensure that the oil circulates and returns back to the tank, or again it will not provide an accurate sample.
You must also take note of when sampling that you do not sample from the bottom of a tank, see the below image.
Now that you have taken the sample and placed the lid on the bottle, you can discard the sample tubing in a correct manner and fill out your label. The label needs to be filled in with as much detail as you can provide.
- Labels
- Your Company name
- Equipment Name
- Compartment
- Date
- Odometer Reading
- Any top up oils
- The Oil type
- Oil Changed or Not
- Oil hours if known
Once completed, place the label on the sample bottle and send immediately, don’t delay sending the sample, it is critical you find out the information on the oils and compartments condition as soon as possible, if there are any problems you wouldn’t want to find out weeks later, this is the reason why you should send immediately.
The Analysis test performed in the Laboratory are dependent on the oil type, the equipment type and the compartment type, all these factors are taken into account when the sample is being analysed, it is important that you are receiving the correct test package to identify the lubricant condition and ability. If you are unsure, please contact Techenomics to evaluate your requirements.
Understanding the Report
Reports are sent via email in pdf format and uploaded to the Online Blue Oceans Software, both reporting option are equivalent with the exceptions that the software can trend equipment, print labels, view entire history by the click of a button and trend alarm levels.
The Website can be found at:
www.techenomics.net
You may view the demo by using details:
Username – demo@tech.com :
Password – demo
For clients wishing to use the online software, please contact your local Techenomics branch to create your account data.
Interpreting the results of your OA is a simple matter of understanding what you are looking at, the report has a lot of numbers, graphs, comments that represent the analysis findings, these are manually written by the Techenomics Laboratory, there are no auto interpretations used within Techenomics.
The First part of the report is the Wear Metal section, these are the metals found in the oil testing at the time of the tests were conducted. We will go through them one by one so you get an idea as to where the metal may come from within the compartment. Metals that are identified are:
- Lead – Usually a soft metal, most common related to Main and Rod Bearings.
- Iron – Most common are Cylinder liners, Rings, Crankshaft, Camshaft, Rods, Valve Train, Oil pump gear, Wrist pins, cast iron components and Gears.
- Aluminium – Pistons, Turbo Bearings, Main and Rod Bearings, pumps, thrust bearings and washers, plates and Aluminium castings.
- Copper – Main and Rod Bearings, Oil Cooler core, Clutch plates, Brass and Bronze bushings and Roller bearing outer cage.
- Chromium – Rings, Liners, Exhaust Valves, Shaft plating, Roller bearings, needle bearings, shafts, rods, gears, stainless steel alloys.
- Tin – Bearings, Brass or Bronze Bushings and Flashing from Pistons.
- Nickel – Alloy Valves, Crankshafts, Camshafts, Bearings and shafts.
Those are probably the most common metals found in Engines, Transmissions, Hydraulic Systems and Gear Systems. You will notice in the comments on the report, it will suggest some of these things if you have high readings.
– A RED smiley face, which represents a problem.
Now we move onto the next section which is the Contaminants in oil, these are:
- Silicon – This is most commonly known as Dirt ingress, other possible causes are from silicone sealants or anti-freeze.
- Sodium – this is salt from water, spray wash or anti-freeze.
Silicon is highly abrasive material and will cause accelerated wear in metal, this loss is due to relative contact between adjacent working parts. Although some wear is to be expected during normal operation, excessive friction causes premature wear. Friction and heat also result in a loss in system efficiency.
Moving onto the Additives, these are blended into the oil for it to withstand extreme pressure, provide better performance and provide greater lubricating protection.
These are:
- Magnesium –detergent and dispersant additive
- Zinc – Alloy in Brass, Anti wear additive, filter canisters.
- Molybdenum – Lubricant additive for reducing friction and wear.
- Calcium – detergent and dispersant additive, lime dust, calcium in water.
- Calcium – detergent and dispersant additive, lime dust, calcium in water.
- Phosphorous – Anti wear additive, Phosphate ester, Phosphate from coolant.
- Boron – Anti wear/extreme pressure agent
Although the overall performance of oil can be improved by introducing additives, poor quality oil cannot be converted into premium quality oil by introducing additives.
Such additives placed in oil are, Acid neutralizers, antifoam, antioxidants, antirust, antiwear agents, corrosion inhibitors, detergents, dispersants, emulsifiers, extreme pressure, oiliness enhancers, pour-point dispersants, tackiness agents and Viscosity index improvers.
Now for the Infra Red section on our report, this is the FTIR analysis – Fourier Transform Infrared, it provides the following test parameters:
- TBN – Total Base Number of oil.
- Soot – Carbon build-up.
- Glycol% – Additive in coolant.
- Water (ppm) – water ingress in oil.
- Fuel Dilution% – % of fuel found in the oil.
- Oxidation – A chemical reaction that forms acids that lead to thickening of the oil.
- Nitration – By products of combustion.
- Sulphation – ability
All these tests are normally preformed on Engine oils, it is important that oil testing is done on each Engine sample to identify Soot levels, whether the Engine has Fuel, water or Glycol in the oil, whether the oil has oxidised, another way of confirming this is by an increase in Viscosity. Nitration and Sulphation are also important as they can highlight problems with blow-by or turbo systems.
Let’s move onto the Physical tests, these tests do not change the chemical nature of the matter, where as the chemical tests do:
- Water% -percentage of water in oil.
- PQ-90 mg/ltr – it measures ferrous particles via magnetics.
- Viscosity @100°c – Oils ability to flow at 100°c.
- Viscosity @40°c – Oils ability to flow at 40°c.
In the top right hand corner there is a Graph displaying the % Variance of the Viscosity of the oil, the centre line indicates the oil as new, where it might have a viscosity of 110 centistokes, if the used oil sample came back with a viscosity reading of 101 centistokes then this would indicate Under the comments section we have Particle Cleanliness Analysis – ISO CODE 4406, these are broken down into particle micron ratings, 4μm, 6μm & 14μm, written as 4/6/14.
The number of particles found under that micron rating is then charted against a range number, this is where the numbers in the field come from, and all charts have the same number and can identify the amount of particles under that micron rating. These particles found could be anything between dirt, wear metals or any other substance that is in the range of that micron rating.
At the bottom of the page we have another graph, this is the Element trend Graph, this trend a couple of the elements found in the report, the legend bar for the colour coding of these is found at the right of the chart. This chart helps to clearly see if you have trends rising in any of the elements.
Silicon is a highly abrasive material and its presence will cause accelerated wear. CHECK SEALS AND BREATHERS. Aluminium levels elevated but still within acceptable limits, aluminium can be related to high silicon levels. Ferrous wear elevated but still within acceptable limits.1.00% Water Contamination Detected. RECOMMEND CHANGE OIL.
Now on to the Limits, Limits are the Blue numbers listed down the right hand side of the report, these numbers are used as a reference when viewing the analysis numbers, the Green, Yellow, Red and Black numbers, When an analysis result is above the limit value, it will highlight either Yellow “Warning” or Red “Problem”, this immediately lets you know that it is above the limit. The limits are established a couple of different ways, limits are either provided by the OEM manufacturers, trended by graphing elements to establish limits, or a generic limit would be set. Limits play an important role because if the limits are set incorrectly, then the notifications of problem samples are also incorrect.
So now we have learnt what the sample number is, the sampled date, the wear metals, contaminants, additives, infra red, physical tests and graphs, the comment section on the elevated samples, recommendations for improvement as well as the oils current condition.
Foaming of Hydraulic Fluid
Almost all lubricating oil systems contain some air. Air is found in four phases: free air, dissolved air, entrained air and foam. Free air is trapped in a system, such as an air pocket in a hydraulic line, and may have minimal contact with the fluid. It can be a contributing factor to other air problems when lines are not bled properly during equipment start-up and free air is drawn into circulating oils.
Dissolved air is not readily drawn out of solution. It becomes a problem when temperatures rise rapidly or pressures drop. Petroleum oils contain as much as 12 percent dissolved air. When a system starts up or when it overheats, this air changes from a dissolved phase into small bubbles. If the bubbles are less than 1 mm in diameter, they remain suspended in the liquid phase of the oil, particularly in high viscosity oils, causing air entrainment, which is characterized as a small amount of air in the form of extremely small bubbles dispersed throughout the bulk of the oil. Air entrainment is treated differently than foam, and is most often a completely separate problem. Some of the potential effects of air entrainment include:
- Pump Cavitation.
- Spongy, erratic operation of hydraulics.
- Loss of precision control, vibrations.
- Oil oxidation.
- Component wear due to reduced lubricant viscosity.
- Equipment shutdown due to low pressure.
Foam testing should be considered as part of your preventative maintenance procedure.
Microscopic Analysis
Another oil testing method used in the Techenomics Laboratories is Microscopic Analysis; the oil is prepared onto a slide enabling it to be viewed under the microscopic at multiple magnitudes, this type of testing method is superb for identifying the types of wear the size of wear and patterns in the wear, all this information helps to gain more of an insight to the compartments condition and the ability the oil has to perform its duties.
The wear found in the micro slide is placed into categories and sized according to the microscopic zoom level, a picture is then taken of the oil and recommendation provided in the comment section.