Your Results

When your sample has been tested in the laboratory, the data from the test equipment is reviewed by Terra Analytical Interpreters who provide an Evaluation Code and a plain English Interpretation Comment.

Interpretation Comments

The Analytical Interpreters consider a wide range of factors when assessing your sample results. Each sample is unique and provides a snapshot of a specific moment in time within that fluid compartment. The information supplied on the sample label is very relevant to this process. It is essential to correctly identify the equipment make, model, and compartment, as well as oil brand, type and grade and hours (or distance) on the oil and equipment. We appreciate that in some cases this information is not available, and we can work around incomplete data if necessary, but the value and accuracy of the sample report improve significantly with quality label information.

We check that the results are consistent with the stated oil type and grade. There are thousands of oil types and grades in the marketplace. Our role is not to recommend which products you should use; this should be discussed with your equipment agent or oil/fluid suppliers. But if the results do not match the oil type and grade stated on the label, we alert you in case the wrong oil type or grade is being used.

Many types of contamination can cause harm to the equipment compartment—dirt, water, fuel, coolant etc. Interpreters look for indicators of these contaminants and alert on them.

Wear metals are a large part of fluid condition monitoring. All equipment wears out over time and metal particles enter the oil/fluid. Normal wear occurs at a low, steady rate and is proportional to the hours on the oil. An increase in this rate means that the life of the equipment is shortened, and a significant increase could indicate abnormal wear from a component in failure mode. Different compartments wear at different rates - there is no simple one-size-fits-all limit. Some OEMs supply wear tables as guides, but many don’t have this information.

Interpreters use trending tools and a range of shared resources and experience to provide a professional opinion on the meaning of your sample results. We are not experts in all possible types of equipment. However, we do see a wide range of fluids in a wide range of equipment compartments, and when any results cause concern, we will draw this to your attention so you can seek the opinion of experts with more specific tools and knowledge.

Test Result Data

Understanding test results is a big subject. The interpretation comments are intended to give a simplified overview/generalised opinion of the action we believe is most likely required. We are not experts in all makes and models and types of equipment. If the report suggests that some action is required, we recommend you consult with the appropriate experts (such as your equipment warranty agent or repairer or oil supplier) as they should have more specific information and inside knowledge and tools.

For a deeper technical understanding of our tests and reports, please refer to Types of Tests.

There are various training institutions and online resources that can also be useful. A reputable independent resource we recommend is There are many sources of information - from equipment makers, fluid suppliers, filter makers and independent consultants. There are many different types of test equipment and various standards organisations involved. Methods and opinions can vary. We aim to keep current with modern best practices and welcome discussion on the methods we use and what we can offer to best suit the needs of equipment users in New Zealand.

Evaluation Codes

eval check circle green

No action required

eval excl tri yellow

Monitor component

eval excl tri red

Action required

eval excl circle red

Urgent action required

Order a Test Kit today

Terra Analytical lab uses a prepaid test kit system which means we can start testing as soon as we receive your samples. The initial cost of the test kit covers the sample bottle and label, outer mailing canister, testing and reporting of the results.

Most sample tests are covered by a standard oil test kit which can also be used for coolant (not fuel).

We have a range of specialty test kits for specific applications. Additional tests and urgent options are available for an additional fee if necessary. Please contact the lab to discuss options.

Test kits are available over the parts counter from Terra Cat branches throughout New Zealand.