Technique
Thermal camera emissivity guide
Why shiny metal lies to infrared cameras and how a reference patch helps.
Short answer
A thermal camera estimates temperature from emitted infrared energy. Polished metal often reflects the room and can produce convincing but incorrect readings.
A practical workflow
- Prefer painted, oxidized or non-metallic target surfaces.
- Use matte electrical tape as a reference patch where safe.
- Allow the patch to reach the target temperature before comparing.
Common mistakes
- Measuring polished metal as if it were painted
- Ignoring reflected hot or cold objects
- Changing emissivity until the result looks expected
Confirmation step: Confirm critical temperatures with an appropriate contact probe and a documented method.
Choosing a camera for this job
Start with native IR resolution, thermal sensitivity, field of view and focus. Close electronics work often needs macro or manual focus; broad building scans benefit from a useful field of view and enough native pixels to resolve an anomaly from a safe distance. Compatibility and reporting workflow matter as much as the headline detector specification.
Compare the exact models in our catalogue →Reviewed August 2026 · Educational information, not a substitute for qualified electrical, mechanical or structural advice.