Thermal imaging cameras are handheld electronic devices with an integrated visual display, designed for detecting heat energy.
The key component of a thermal camera is a heat sensor attached to a special type of lens, which is then adapted to work alongside standard image-capture technologies. This allows engineers to quickly identify regions of excessive temperature or sources of wasted heat energy, such as overheating components or potential thermal insulation gaps in building inspection.
Visible light forms only a small part of the electromagnetic spectrum, and the only part we can actually see. When pointed at an object or area, the sensor on a thermal detection camera allows the user to view the otherwise invisible infrared spectrum, which exists at wavelengths between visible light and microwaves.
This is often rendered as a colour map in modern IR cameras, although black-and-white displays are still preferred for certain applications due to their reduced visual ‘busyness’ and improved capture of fine detail.
On a colour thermographic display, warmer components or regions will show up as reds, oranges and yellows, while cooler parts will typically be shown as purples and blues (green usually indicates areas that are roughly at room temperature). Because they measure infrared radiation, and not visible light, thermal cameras are also useful for identifying heat sources in very dark or otherwise obscured environments.