What effect does solar absorption have on a component when viewed with an IR camera?

• A. Hotter than it really is; both look and measure. Colder is reflective
• B. Cooler than it really is
• C. No effect on apparent temperature
• D. Only affects color, not temperature

Answer: (A)

Solar energy absorbed by a surface raises its temperature. An infrared camera reads temperature by detecting emitted infrared radiation, which increases as the surface gets hotter. So a component heated by the sun will look hotter in the image and also show a higher temperature in the reading, even if the ambient temperature hasn’t changed. If a surface is highly reflective in the infrared, it can also pick up radiation from the surroundings, which can further skew the reading, but the main effect of solar absorption is to make it both look and measure hotter.