What Makes a Good Thermogram?
A good thermogram is more than a colourful thermal image. It should clearly show the thermal pattern, the target being inspected and the information needed for reliable interpretation.
From focus and framing to measurement settings and inspection conditions, a few simple checks can make a big difference. Here are 6 things to look for when capturing a good thermogram.
1. Correct Measurement Settings
- Before starting, use an appropriate emissivity setting.
- 0.95 for most inspections, especially electrical.
- Avoid relying on shiny, low emissivity surfaces for accurate measurement, look around for clues that could provide more insight.
- Consider reflected apparent temperature (RAT) where relevant.
2. Captured Under the Right Conditions
- Ensure:
- Equipment is operating under suitable conditions. Best when operational.
- Environmental conditions are ideal for inspections.
3. Sharp & Focused
- Ensure target is in focus.
- Poor focus can affect reading and cannot be adjusted in the software.
- Important details are captured and visible.
- Target is large enough for reliable measurement.
4. Image is Well Framed
- Clearly show what is being inspected.
- Centre the target.
- Get as close as possible, within a safe distance. Near is clear.
- Uses a suitable viewing angle.
- Information can be lost if the angle is too small.
- Include enough surrounding context.
5. Properly Tuned
- Select a palette that makes the image easy to understand.
- Use the appropriate mode: full infrared image, thermal overlay, Picture-in-picture.
- We recommend you start with full infrared, before using thermal overlay options once you’re confident your image is focused.
- Pro-tip: Adjusting the level and span can help to enhance the thermal pattern.
6. Misleading Reflections
- Be aware of shiny and low-emissivity surfaces. Those tend to be reflective.
- Lookout for reflected heat sources.
- Most around and change viewing angle to avoid capturing a reflected hot spot which could lead to a misdiagnosis.
A real hot spot like the one on the left doesn’t “move” around, unlike the right where the thermographer’s reflection can be seen moving in-and-out.
Simple Quick Check
Right Conditions • Correct Settings • Focused • Framed • Tuned • No Reflection
A good thermogram should clearly show the thermal pattern while preserving the information needed for reliable interpretation.
A good thermogram doesn’t have to look impressive — it needs to be clear, representative and useful for analysis.
Before moving on to the next target, take a moment to check: Is it focused? Is the target clear? Is the image properly tuned? Could there be reflections? Are my measurement settings appropriate? Were the conditions suitable?
Getting these basics right at the point of capture gives you better information to work with later — whether you’re analysing a potential anomaly or preparing your thermography report.
Keep Learning About Thermography Reporting
Explore our other guides on Infrared Thermal reporting:
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