Thermal imaging can be used in lots of different scenarios. Energy and utility companies can use it to see where houses might be losing heat through window cracks and doors. Police helicopters use it to locate and track suspects at night. Weather trackers can use it to find hurricanes and storms. It can also be used in the medical field to track fevers and diagnose different diseases and disorders. Home security doorbells, such as Ring Doorbells, can use it too.
What is Thermal Imaging?
Thermal imaging is a type of camera imaging that allows you to see the heat of an object as it radiates off the object. Thermal cameras can be used to record the temperature of various objects in the frame. It assigns each temperature a certain shade of a color. This lets you see how much heat it has compared to the objects around it.
Colder temperatures normally show a shade of purple, blue, or green. In addition, warmer temperatures show shades of red, yellow, or orange. Because of this, the person or object with hotter temperatures will stand out because of the differences in colors. Some thermal cameras may use grayscale instead. Most police helicopters use grayscale, so the suspects stand out more.
How Does Thermal Imaging Work?
Thermal imaging cameras detect the temperature by capturing and recognizing the different levels of infrared light. You can’t see this light with the naked eye, but you can feel it as heat if the intensity is enough.
Every object emits a different type of infrared radiation, and it is how heat transfers. If you hold your hand over something hot, like a fire, it is emitting a lot of infrared radiation, and the heat transfers to your hand. For example, only half of the sun’s energy is emitted as visible light; the rest is infrared and ultraviolet light. The more head an object radiates, the more infrared radiation it emits. Thermal cameras see this radiation and convert it to an image that we can see through colors with our eyes. It is just like how night vision cameras can capture invisible infrared light and make it into a picture we can see.
Inside a thermal camera, there are some tiny measuring devices. These devices capture infrared radiation, called microbolometers. From here, the microbolometer measures the temperature and assigns a pixel that is an appropriate color. Most thermal cameras have a low resolution compared to modern televisions and other displays because of this. A good resolution for a thermal camera is 640×480.
How is it Different from Night Vision?
Technically thermal imaging can be called a different type of night vision. For example, in police helicopters, thermal night vision is an advantage. This is because it can easily differentiate between a person and the rest of the environment. This makes it easier to sport suspects in the dark and also in broad daylight when someone might have blended in with their surrounding environment. However, most thermal imaging cameras rely on the wavelengths of infrared. Your typical night vision security camera usually captures shorter wavelengths of infrared, and it cheaper to manufacture. Thermal cameras have the ability to capture longer wavelengths of infrared, which allows it to detect heat.