Since night vision sights and other high-tech equipment became a mainstay in military applications, it has continued to evolve. One of the major fruits of evolving night vision equipment is thermal imaging technology.
In this article, we’ll be delving into more details on thermal imaging, its types, applications, features, and more.
Thermal Imaging Technology
All objects give off some degree of heat. The heat emitted from objects comprises long-wave infrared rays invisible to humans. With thermal imaging technology, humans can see these images and make sense of environments.
Thermal imaging technology makes use of sensors that converts infrared rays to images. Several applications benefit from thermal imaging technology (more on this below). But as expected, thermal imaging has some limitations, like peeking through glass, for example.
These imagers make use of two heat detection processes – pyro-electric sensors and resistive bio-meters. Without one of these detection processes, thermal imaging isn’t possible.
Types of Thermal Imaging Devices
Two kinds of thermal imaging devices are available:
Cryo-cooled thermal imagers:
Cryogenic cooling keeps these thermal imagers at temperatures less than 32°F. The cooling process takes place in a specially designed container. With this cooling process, these thermal imagers can render more explicit images with superior sensitivity and resolution.
Cryo-cooled imagers can spot differences in less than 0.3°F. These imagers can also pick up heat signatures for up to a thousand feet away. These imagers help you make sense of objects at far distances and cost more money overall.
Uncooled thermal imagers:
These imagers operate around 75°F and have all components of their system built-in. It’s the least expensive option compared to cryo-cooled thermal imagers and renders images with a lower resolution.
Besides helping hunters see in dark environments, thermal imagers can perform needed functions elsewhere. Thermal imaging technology makes it easy to spot temperature differences without needing any artificial lighting. Thermal imagers can see through some bushes, smoke, fog, etc.
Application of thermal imagers can function in:
– Assessment of buildings’ structural profiles
– Fire fighting
– Law enforcement
– Surveillance operations (perimeter, large expanse, etc.)
– Forensic analysis
– Analysis of auto faults
– Screening of bearings, electrical panels, etc.
– Rescue operations
Thermal imagers are suitable for assessing different environments. In most cases, how these imagers can be used depends on few characteristics and your field of view. For example, moving targets may be much harder to spot than bodies that aren’t moving.
Most thermal imagers are ideal for locating threats when you don’t want to attract attention with visible light. Rescue and first-responder operations are much more manageable with thermal imagers in the dead of night.
When it comes to hunting, thermal imagers makes it much easier to spot game in foliage or pitch darkness. If you need to take multiple stealth shots without being seen, thermal imagers are a must-have.
These imagers also help in making sense of what caused an accident. Imagers can help law enforcement accurately measure skid marks, check for wiped bloodstains, checking for pollutants, and much more.
Thermal imaging devices are available in monochrome (black and white) and colored.
Monochrome thermal imagers are usually cheaper and render the entire environment in black and white. Objects that emit heat (humans/animals, fire, etc.) appear in white. Cold objects like rocks, trees, etc. appear in black on feeds from monochrome thermal imagers.
Colored thermal imagers usually have eight colors and have improved identification of hot and cold objects. With colored thermal imagers, you can see hot objects in yellow, dark blue, or red. Some colored thermal imagers with advanced features can render cold objects in light blue or black.
Superior thermal imagers could be ideal for all forms of activity. But if you plan to buy a budget thermal imager, its features may be determined by select elements. Among these elements are:
– Maximum operating temperature
– Power consumption rate
– Average battery life
– Lens power
Thermal imaging devices tend to cost much more when they possess a superior focal length. In most cases, thermal imaging devices with enhanced magnification could cost north of $2,000. Some handheld options usually possess easy adjust functions.
However, high-powered lenses could need motorized lenses and are likely to cost more. Thermal imagers leverage f/1 lenses. Most of these lenses have focal lengths with identical parameters to the diameter of their lens aperture.
Lenses on thermal imagers usually cost more than inbuilt heat detectors. Many thermal imaging devices draw most of their functions from the lens in use. Infrared rays can’t get through normal glass. Special compounds go into producing lenses used in thermal imagers. In some cases, thermal imagers could have superior lenses to camcorders.
When experienced buyers plan to buy thermal imagers, it is important to check lens features. Lens elements like the field of view, focal length, choice material, and more should get a close look before purchase.
Final Thoughts: Thermal Imaging Technology
When you’re selecting thermal imagers, you need to get the hang of their response rate. You don’t want to be outdoors or at the scene of a fire with an underperforming thermal imager. Also, make sure you select a thermal imager with a decent infrared sensitivity (preferably lower than 100mK).
A quality thermal imager should possess the ability to render a clear picture across several infrared (IR) beams. That’s why you need to ensure your preferred thermal imager has about 50dB or higher.
Besides possessing IR sensitivity and rendering capacity, it should have an improved wavelength spectrum. An increased wavelength sensitivity ratio improves images across the IR range.
Other parameters to consider are the array size and detector pitch. Making the most of your thermal imager depends on these features. With the right thermal imager, it becomes easy to get better heat signatures at close or far distances.