How an Infrared Thermal Imaging Camera Works

Understanding how an infrared thermal imaging camera works may be a bit complicated for some, but it is actually easy to understand. There are a lot of people who use infrared thermal imaging but never really understand how it works or how it is processed.

The Basics

An infrared thermal imaging camera basically detects light. The quantity of energy found in a light wave is correlated to its wavelength. The longer the wavelength is, the lower energy it has. This kind of energy can only be detected by an infrared thermal imaging camera. Aside from light waves, there are visible lights and these are better known to us as colors.

Among all the colors that we have, violet has the most energy and red has the least energy. Because of this, the terms “Ultraviolet” and “Infrared” came to be. All lights that are below red or are darker than red are considered “infrared,” which is not visible to the human eye but is visible through thermal imaging cameras.

Three Kinds of Infrared Lights

The infrared lights can be categorized into three groups. They are the near infrared, mid infrared and thermal infrared. Near infrared is the nearest to visible light and has the wavelength between 0.7 to 1.3 microns. Mid infrared has a wavelength between 1.3 to 3 microns. Both the near infrared and the mid infrared are being utilized in common electronic devices in our world today. Some of them are remote controls, cellular phones and electronic switches.

Thermal infrared is the one that has the largest part of the “Spectrum of Light”, while near infrared is between 0.7 to 1.3 microns and mid infrared is between 1.3 to 3 microns (the thermal infrared is between 3 to 30 microns).

How It Is Processed

An infrared thermal imaging camera uses a special lens that is focused mainly of infrared light emitted by all the objects that it can see. The infrared light emitted is processed by an array of infrared detectors, which then creates a temperature pattern that is also known as “thermogram”. The entire process from obtaining the infrared light to making a thermogram takes approximately 0.033 milliseconds. After the thermogram is created, it is then made into an electrical impulse.

The electric impulse that was made from the thermogram is then sent to a single processing unit or a circuit board that is mainly focused on transmitting the signal into a data for display. Once the data has been sent to the display, people are be able to see various colors depending on the intensity of the emission of the infrared light. Through the different combinations that came from the impulses made by different objects, an infrared thermal image is then created.

Sometimes, infrared cameras are best utilized when people want to see the things that cannot be seen by the naked eye. They are also being utilized by the military because the infrared thermal camera allows them to see in the dark.