10 tips for the OELCHECK laboratory report

Year of publication: 2003


The OELCHECK lap reports provide you with a variety of values that inform you about the condition of your units and transfer insights into the lubricant you are applying. Although you can always count on the diagnosis of the experienced OELCHECK tribologists, you should not consider the lab report to be a closed book to you. In order to make sure you are profiting the most from those experiences, we have created a list containing the 10 best tips on how to decipher the data in a quick and perfect manner.

Table of contents

  1. Tip: Interacting with your units on a personal level
  2. Tip: OELCHECK needs your feedback.
  3. Tip: Everything is relative – estimate the dimensions correctly
  4. Tip: First aid – urgent matters have priority
  5. Tip: You can’t be too careful – check the basis data
  6. Tip: OELCHECK lab report
  7. Tip: A decision is due – information is key
  8. Tip: A severe case – stay calm
  9. Tip: Practice makes perfect
  10. Tip: Those who are late...

Tip: Interacting with your units on a personal level

Only those who are familiar with their units and know what the oil comes in contact with during operation are capable of putting the knowledge gained from the lab report into action. You will only know your units inside out once you are familiar with:

  • the operating mode
  • the operating conditions
  • the maintenance measures
  • the applied lubricant
  • the repairs already performed

By the way: Detailed information about the changing of filter cartridges or the refilling of a lubricant are also important for a better assessment of correlations.

Tip: OELCHECK needs your feedback.

OELCHECK is your partner. We decipher the message of the oil – together with you. We can contribute our knowledge about all chemical and physical test methods and, due to our experiences from similar applications, make a diagnosis about the condition of the unit and the used lubricant. Nevertheless, you have to complete our analysis with your knowledge from practical experience. Only you know the exact application, possible changes of the operating conditions or potential damage and can therefore establish a connection to a previous analysis.

Without understanding indications from the oil analysis, you would only be able to superficially apprehend that certain values from the analysis are reliable indicators for future changes of your unit. We can sometimes only draw insufficient conclusions and give inaccurate diagnoses without your feedback about the operating conditions of your unit.

If you want to receive more accurate commentaries with your lab reports, it is of vital importance that, using the Sample Information Form, you inform OELCHECK if you have:

  • conducted measures for oil maintenance
  • refilled oil
  • noticed changes regarding the unit
  • changed operating conditions decisively.

Tip: Everything is relative – estimate the dimensions correctly

Imagine: You receive a laboratory report and the value of a certain wear metal, e.g. iron, has doubled from 2 mg/kg to 4 mg/kg. An increase of 100% – and the expert from OELCHECK does not mention any of this in his commentary!

Well, nobody is immune to mistakes. However, in lubricant analysis, even a doubling is always relative. After all, in most cases the quantities are mg/kg or ppm, (parts per million) and thus vanishingly small quantities, because 1 mg/kg or 1 ppm corresponds to only 0.0001 %.

A simple example illustrates the relationships: An ordinary metal paper clip is dissolved in a liter of oil. Afterwards, a sample of this oil is analyzed in the lab. Approximately 500 mg/kg of iron is determined. This value seems to be quite high at first glance, nevertheless, this quantity is relative. In relation to the total volume of the sample, the iron value of 500 mg/kg (0.05%) is very small.

If the measured values of a wear metal change from sample to sample in trend analyses, the following aspects must be taken into account:

  • Which components of the unit consist of or contain the concerned metal?
  • How big is the surface area of these components that come into contact with the lubricant?
  • How big is the total amount of oil in which the wear metal is dissolved?

One of the biggest difficulties when interpreting an oil analysis is deciding and determining whether wear has occurred on all or only some surface areas of components made of the concerned metal.

Here is an example: A 20 kWh drive gear is filled with 5 liters of oil. The iron value has increased from tolerable 15 mg/kg to 281 mg/kg within 1000 hours. Was the reason for this increase in iron corrosive wear of all gear components containing iron or rather abrasive wear of tooth flanks?

Tip: First aid – urgent matters have priority

In case you receive several lab reports, process possible critical cases first. OELCHECK helps you to identify those immediately. You can find a symbol on each of our lab reports in the upper right corner:

  • green check = normal – everything is okay
  • yellow i = hint - OELCHECK has noticed abnormalities. Read the text.
  • red ! = attention – process immediately. Measures have to be taken. An oil change is due or there are serious changes that require your action.

Sort the lab reports according to their priority and process those marked with an “!” immediately.

It is much easier if you are in possession of an access to www.lab.report Samples that you have not yet checked since your last login are sorted by the colors green, yellow and red. When clicking on “red” you can see all samples that require action.

Tip: You can’t be too careful – check the basis data

Since you stick on the laboratory number, a confusion of samples at OELCHECK is impossible. With the help of the barcode system, each sample is clearly assigned to the attached Sample Information Form. Each sample can be tracked at any time in our system. Nevertheless, check whether your address has been captured correctly and whether your e-mail address has been entered for a very quick delivery of your lab results.

  • Are you the right recipient?
  • Are form of organization, address, phone number, fax and e-mail address correct?

Check your indications (possibly with reference to a previous analysis):

  • Did you provide the correct information regarding the unit and the lubricant? You can find them in the upper left corner of the laboratory report, directly under the address.
  • Are all of the previous lab results specified completely in the same report? Let’s merge related samples using one denotation.
  • How big is the time frame between the sampling date and the analysis date of the sample? All samples are analyzed within 24 hours in the OELCHECK laboratory.  Is the sample with you too long or have you chosen a shipping route that causes delays?
  • Have all operating indications been collected correctly? Are there any precise indications concerning the age of your unit? How long has the oil been in use since the last oil change? This information is of vital importance for OELCHECK, as all attested wear metals and many of the impurities correlate directly with the age of the unit and the operating time of the oil. If you do not indicate any operating time, the significance of the diagnosis weakens.
  • Did you top up oil in order to keep the oil level at the correct level? Topped up oil quantities (especially those carried out using a different type of oil) also have an impact on the results of the analysis. They can change the concentration of the additives, dilute the level of impurities and reduce the values of wear metals. If there are no indications relating to the top up volume, the diagnosis can be inaccurate.
  • Last but not least – did you provide all information concerning the lubricant? Manufacturer, unit ID and viscosity should be complete and correct. Unfortunately, this has not become any easier due to the merging of many companies within the lubricant sector.

Tip: OELCHECK lab report

Above in the pink field: Our diagnosis! Please read it first before jumping into the individual data thirsting for knowledge. The expert from OELCHECK shares his evaluation of the results in a short manner and advises you on further steps. At the same time, this commentary by the tribologist is intended to sensitize you for looking at individual values.

In case you receive special hints “i” or even warning signs “!” from the experienced tribologist, objected values are already referenced in his commentary most of the time. OELCHECK has arranged the lab report in a way that helps you to get a quick read. No confusing abbreviations or technical terms can be found within the text. The data of the current sample is highlighted in bold. In the case of trend analyses, the results of the four previous analyses are listed chronologically next to each other.

The measured values are logically listed according to category. Thus, the reader is capable of finding the respective relevant data under the categories wear, impurities, oil condition and additives.

One of the most important categories is the category “wear”. All classic wear metals are listed here and the PQ index is also given, which provides information about the magnetizable iron abrasion in the sample.

The following overview shows which metals in which units or components usually indicate wear:













Mobile hydraulic oil

X X X     X   X X X

Industrial hydraulic oil

X     X   X X      

Bio hydraulic oil

X         X     X  

Diesel engines

X X   X X X   X   X

Gas engines

X X X X   X X X    

Petrol engines

X     X   X   X    

Aircraft engines

X X   X X X X X    

Stationary Engines

X X   X         X  

Industrial gears

X       X X   X    

Planet gears

X X       X       X


X X     X X   X X X

Distributor gears

X         X   X X  

Final drives

X X           X X X

Belt drive gears

X     X       X X X

Screw compressors

X         X   X X X

Pisten compressor

X X X     X X      

Rotary compressor

X   X X   X   X   X

Refrigerating compressor

X   X     X     X X

Heat transfer plants

X     X           X

Steam turbines

X   X     X X      

Gas turbines

X         X   X X X

Water turbines

    X     X X   X  

Lubricating grease

X X           X X X

Rolling bearing
and ball bearing

X X     X X        

Slewing bearing

X X X X X X X X X  

Taper roller thrust

X X           X    

Plain bearing

X   X     X X X X  

Diesel fuel

X             X X  

This table shows the elements which our experienced OELCHECK tribologists often named as cause for an oil change or an inspection.

Tip: A decision is due – information is key

When you receive a lab report with a warning sign “i” and quick action is necessary: take it one step at a time. Take step after step and make sure whether the analyzed sample was really taken as a reference sample in such a way that the determined values are representative of the total filling volume. Also, try to find out whether the operator of the unit or your employees responsible for the maintenance have noticed any abnormalities regarding the unit.

These could consist of intensified vibrations, operating noises or a high increase in the operating temperature. Gather all information and tackle the problem effectively.

Tip: A severe case – stay calm

In case you are suddenly confronted with an extraordinary laboratory report, consider it a timely warning and stay calm. A planned course of action includes consulting with operations and maintenance on the necessary steps. Perhaps also talk to your tribologist and ask whether a different analysis is possible considering your operational specifics.

A value which deviates from the trend can refer to a serious problem, but it doesn’t have to. Please also keep in mind that the individual analysis on its own is not necessarily meaningful either. Also always consider the previous analyses in your considerations.

However, you should not underestimate a warning sign just because there were no problems when you ignored it in the case of a different unit. Do not wait until the results of the next analysis are available.

Tip: Practice makes perfect

The same applies to the interpretation of the lab reports: Practice makes perfect Acquire the necessary routine. Especially as a novice you should concern yourself intensively with the reports and their methodology in the beginning. You may also read our articles concerning limit values and inform yourself on our website www.oelcheck.com about our test methods.

Read the lab reports as close to the action as possible, that is, where you have all the necessary information at hand as quickly as possible. If you have questions about causes of wear metals, forward the lab report by email to the unit manufacturer, who can often give you clues regarding the affected wear part based on their spare parts statistics.

Tip: Those who are late...

might find a nasty surprise. Do not ignore any of the lab reports containing a “i” or “!”. Read them immediately. In case you are absent on business make sure someone steps in for you or your emails are being forwarded.

After all, there are lab reports where time is money. You can only avert imminent damage if you react carefully but quickly at the same time. That’s why OELCHECK offers the much faster email dispatch or access via the customer portal next to the general postal shipping.