How to Read an Infrared Thermography Report

How to Read an Infrared Thermography Report

You have received an infrared thermography inspection report.

There are thermal images, temperature numbers, severity classifications, and repair recommendations — and it is not always immediately clear what it all means or what you are supposed to do next.

This guide explains exactly how to read a professional thermographic inspection report, what each section tells you, and how to use the findings to make decisions.

Key Takeaways

• A thermographic report documents every thermal anomaly found during the inspection, along with its location, severity, and recommended action
• Paired thermal and visual images allow you to identify exactly where a finding is located in the physical space
• Severity classification tells you how urgently a finding needs to be addressed
• Temperature differential — not absolute temperature — is the primary measure used to assess fault severity
• The report is a working document — it should be shared with your contractor, filed with your maintenance records, and provided to your insurer

The Structure of a Professional Thermographic Report

A well-structured thermographic inspection report contains several key components. Understanding each one helps you use the report effectively.

Cover and scope summary — identifies the facility inspected, the date of inspection, the technician, and the scope of assets covered. This section confirms what was and was not included in the inspection.

Asset inventory — lists all electrical assets that were inspected, including panels, switchgear, motor control centres, and other equipment. This is your reference for confirming that everything you expected to be inspected was covered.

Findings section — the core of the report. Each finding is documented individually with the information needed to identify, understand, and act on the issue.

Summary table — a consolidated list of all findings, organized by severity, for quick review and prioritization.

Recommendations — specific corrective action guidance for each finding.

Understanding Thermal and Visual Image Pairing

Every finding in a professional thermographic report is documented with two images side by side: a thermal image and a standard visual photograph of the same component.

The thermal image shows the heat distribution across the component using a colour scale — typically moving from dark (cooler) to bright (hotter). The hottest areas appear as bright yellow, orange, or white depending on the colour palette used.

The visual image shows what the component actually looks like — its physical location, labeling, and surrounding context.

Together, these two images give you the ability to identify exactly which component the finding relates to and locate it precisely within your facility. If you are sending the report to an electrical contractor, these paired images are what the contractor will use to find and assess the fault without needing a site walk with the inspector.

Reading Temperature Differential Data

The most important number in a thermographic finding is not the absolute temperature of the hot component — it is the temperature differential (often written as ΔT) between the affected component and a reference point.

The reference point is typically a similar component operating under similar load conditions nearby. For example, if one phase of a three-phase breaker reads 65°C and the other two phases read 40°C, the temperature differential for the anomalous phase is 25°C.

Temperature differential matters more than absolute temperature because it isolates the abnormal heat generated by the fault from the normal operating temperature of the equipment. A component running at 65°C in an ambient environment of 60°C is not necessarily a problem. The same component running 25°C hotter than its identical neighbours almost certainly is.

Understanding Severity Classifications

Professional thermographic reports classify each finding by severity level based on the temperature differential observed.

While classification systems vary slightly between providers, a common framework looks like this:

• Low / Monitor — ΔT under 10°C. Minor anomaly, monitor and address during next scheduled maintenance
• Moderate / Plan — ΔT of 10–30°C. Elevated fault risk, plan for repair within 30 days
• High / Urgent — ΔT of 30–60°C. Significant fault risk, repair as soon as possible
• Critical / Immediate — ΔT over 60°C or immediate fire or failure risk, action required before next operation

Severity classification is the first thing to look at when reviewing a report. It tells you immediately whether you are dealing with something that can wait for a scheduled maintenance window or something that needs a phone call to your electrical contractor today.

What to Do With the Repair Recommendations

Each finding in the report includes a specific repair recommendation describing the corrective action required.

These recommendations are written for the electrical contractor who will perform the work — not for general audiences. If the language is technical, that is intentional. Share the relevant findings directly with your contractor.

Your contractor should be able to use the thermal image, visual image, location description, temperature data, and repair recommendation to assess and address the fault without requiring a separate site visit with the inspector in most cases.

Filing and Using the Report

A thermographic inspection report is a working document with several uses beyond the immediate repair cycle.

Maintenance records — file the report with your facility maintenance documentation. Over multiple inspection cycles, these reports create a trend record that identifies assets that are consistently developing thermal anomalies — a signal that more significant intervention may be needed.

Insurance documentation — provide the report to your insurance broker for inclusion in your renewal submission. Structured thermographic reports satisfy insurer expectations for documented preventive maintenance programs.

Contractor follow-up — share relevant findings with your electrical contractor and request confirmation when repairs are completed. Schedule a follow-up inspection to verify resolution.

For more on the full post-inspection process, see our post on what happens after a hotspot is found during an infrared inspection.

Frequently Asked Questions

What if I do not understand a finding in my report?

Contact IRIS PDM directly. Our technicians are available to walk through report findings with facility managers, maintenance teams, and electrical contractors. Understanding what was found and why it matters is part of the service.

Can I share the report directly with my electrical contractor?

Yes — and you should. IRIS PDM reports are structured specifically to give electrical contractors the information they need to locate, assess, and repair identified faults without requiring additional diagnostic work. The paired thermal and visual images, location descriptions, and repair recommendations are all written with the contractor in mind.

What does it mean if the report has no findings?

A report with no findings is a clean bill of health for the assets inspected at the time of the inspection. It confirms that no significant thermal anomalies were detected under the load conditions present during the scan. File it with your maintenance records and schedule the next annual inspection.

How long should I keep thermographic inspection reports?

Retain reports for a minimum of five years. Insurance carriers and institutional clients may request historical inspection documentation during claims review, policy renewal, or audit processes. Longer retention periods provide stronger evidence of a consistent preventive maintenance program.

What is the difference between a thermal image and an infrared photo?

These terms are often used interchangeably. Both refer to images captured by an infrared camera that represent heat distribution rather than visible light. The colour scale in a thermal image represents temperature — not actual colour — and is used by trained thermographers to identify and measure thermal anomalies in electrical and mechanical systems.

To learn more about our infrared inspection services and what our reports include, visit our Infrared Electrical Inspection Services page.