Transformer Oil Sampling

Ensuring Accuracy in Transformer Maintenance & Diagnostics

Proper transformer oil sampling is the critical first step in any oil diagnostics process. Whether you are performing predictive maintenance oil diagnostics or routine lubricant oil analysis, IEC 60475 compliant oil sampling for transformers ensures the accuracy of laboratory results.

Simply put: the quality of the oil test result is only as good as the sample collected.

At EA Technology, our highly trained Technical Engineers carry out oil sampling from oil-filled transformers and other high-voltage assets. Before any sampling takes place, we perform a thorough on-site risk assessment to ensure all safety and operational considerations are addressed.

Sampling Methodology

Our sampling process follows IEC 60475 international standards, which outline the correct methods for obtaining oil samples without introducing contamination. This is crucial for detecting issues such as:

• Dissolved gas presence
• Moisture content
• Insulating oil degradation
• Particulate contamination

Using industry-approved methods helps asset owners make informed maintenance decisions, plan repairs, and extend transformer service life. This service also supports our broader Transformer Condition Assessment programs for optimised asset management.

We also offer Switchgear Oil Analysis for other oil-filled equipment beyond transformers.

Equipment Used – Transformer Sampling Kit

For accurate results, we use a specialised transformer oil sampling kit. Key features include:

• 500ml glass bottles with polycone caps to prevent gas escape (plastic vessels are never used for transformer oil samples).
• A secondary sampling tap that allows oil to enter from the bottom of the bottle at a steady rate, reducing turbulence and minimising contamination risk.
• A process for measuring and recording oil temperature at the time of sampling to help assess moisture content accurately.

Oil Diagnostics – Logistics

Once collected, safe and secure transportation is essential for preserving sample integrity. EA Technology uses robust, oil-resistant transportation crates that:

• Hold up to 12 amber or clear glass bottles
  
  
• Include pre-labelled return addresses and contact information for our Oil Diagnostic Facility
  
  
• Contain foam inserts to prevent breakage during transit
  
  
• Come with a laminated Quick Guide – Transformer Oil Sampling
  
  

Crates are sealed with clips before shipping, and can be:

• Collected by highly trained Technical Engineers
  
  
• Dropped off directly at our Oil Diagnostic Facility
  
  
• Shipped via an approved courier

All containers are designed to meet transformer oil sampling best practices, ensuring samples arrive at the laboratory in optimal condition.

Why Correct Oil Sampling Matters

Correct transformer oil sampling is more than a procedural step—it’s a key factor in the reliability and performance of transformer maintenance programs. Accurate samples allow for early detection of insulation breakdown, moisture ingress, or other issues, enabling predictive maintenance oil diagnostics that reduce downtime and extend asset lifespan.

For deeper insights into oil condition testing and asset health, explore our Transformer Oil Diagnostics service or browse the latest updates in our News & Blogs section.