How do infrared waves enable thermal imaging?

Infrared waves enable thermal imaging by detecting heat radiation emitted by objects and converting it into visible images.

Infrared radiation, also known as heat radiation, is a type of electromagnetic wave that is invisible to the human eye. However, all objects emit some level of infrared radiation depending on their temperature. The hotter an object is, the more infrared radiation it emits. This is where thermal imaging comes into play.

Thermal imaging cameras are designed to detect this infrared radiation. They work by using a special lens to focus the infrared light emitted by all of the objects in view. This focused light is scanned by a phased array of infrared-detector elements, which create a detailed temperature pattern called a thermogram. The thermogram is then converted into electrical impulses.

These electrical impulses are sent to a signal-processing unit, a circuit board with a dedicated chip that translates the information from the elements into data for the display. The signal-processing unit sends the information to the display, where it appears as various colours depending on the intensity of the infrared emission. The combination of all the impulses from all of the elements creates the image.

Different colours in the image represent different temperatures, allowing the user to see variations in temperature. For example, objects emitting more heat may appear as red or white, while cooler objects may appear as blue or black. This enables the user to identify objects, people, or areas of concern based on their heat signature, even in total darkness or through smoke.

In summary, infrared waves enable thermal imaging by allowing special cameras to detect and visualise the heat radiation emitted by objects. This technology has a wide range of applications, from night vision and surveillance to medical diagnostics and building inspections.