You have likely heard of the electromagnetic spectrum before in science class, but you may not remember that the visible light our naked eye can perceive only makes up a very small part of the whole electromagnetic spectrum. Much more of the spectrum is actually invisible to the naked eye and requires complicated, specialized devices in order for us to be able to “see” and measure information about their rays. There are several types of rays on the electromagnetic spectrum, including gamma rays, x-rays, ultraviolet light, visible light, infrared rays, radar waves, microwaves, television waves, and radio waves, each varying in wavelength and frequency. Specifically, this article is interested in infrared rays and how they are used to inform and improve our lives via Infrared Thermography (IRT).
What is Infrared Thermography (IRT)?
Infrared Thermography is the process of translating thermal energy radiation, otherwise known as heat or infrared rays, into a visible image. This image is called a thermogram, and the process used to analyze these images is called thermography. Because all objects above absolute zero (-273.15 °C or -459.67 °F or zero kelvins) radiate some level of thermal energy/heat in the form of infrared rays, we can use devices called infrared cameras to produce thermographic images that translate this invisible infrared radiation (IR) into images that show how different materials give off heat or cold energy at different rates.
The History of Infrared Thermography and Thermal Imaging Cameras
Infrared Thermography is not a new concept. Its discovery was spurred by an experiment performed in the year 1800 by Sir William Herschel - an astronomer for the King of England and well known for his discovery of Uranus as a planet - as he sought to find a material that would allow for direct viewing of the Sun during solar observations by reducing the Sun’s brightness via an optical filter for telescopes. By recreating Sir Isaac Newton’s famous prism experiment, and looking at the heat radiation produced by each color of the visual portion of the electromagnetic spectrum, he discovered the heating effect doesn’t reach its maximum until far beyond the red end of the visual spectrum. Herschel referred to this newly discovered portion of the electromagnetic spectrum as the “thermometrical spectrum”, and its rays were invisible to the naked eye. The heat radiation produced by what would come to be known as “infrared wavelengths” was referred to by Herschel as “dark heat” or “invisible rays”. (source)
Thermal imaging has come a long way since Herschel’s initial discovery. Fast forward all the way to 1929 and that is when the first infrared-sensitive electronic television camera for anti-aircraft defense was produced in Britain. During the Korean war in the early 1950’s, thermal imaging cameras were used in the field to detect enemies and supplies even in the dark or when shrouded with smoke. From then on, thermal imaging cameras became a useful and commonly used tool for the military, whether in wartime or not. In 1970, the development of the pyroelectric tube allowed for the first naval thermal imager to be used by the Royal Navy in Britain for battle. In 1978, IR imaging systems were being utilized for the first time for energy audit and fire detection applications. Finally, in 1992, the U.S. government decided to declassify thermal imaging technology due to its potential to be used in a wide variety of civilian applications. (source)
Today, there are many thermal camera uses for a multitude of professions or even for personal usage. These range anywhere from home inspections to healthcare, first responders to wildlife tracking, road safety to gas detection, and so on. In fact, thermal imaging cameras have become a huge part of many functions in society, making it possible to perform many different essential functions that would have been much more dangerous otherwise (mechanical performance monitoring, plant inspections, search and rescue, etc.) now safer, more efficient, and more affordable.
How do Thermal Imaging Cameras Work?
In order to understand how y that it does not create images from reflected light like the human eye or normal cameras - instead, thermal imagers make pictures from heat signatures picked up by its infrared sensors (source). This means that thermal imaging does not require any kind of light in order to work, making thermal imagers much more effective than other types of cameras during dark, inclement, or obscured conditions.
An infrared camera contains the following essential elements (source):
●A thermal sensor, which quickly and accurately picks up thermal radiation energy (heat) signatures. The thermal sensor is the most important part of the thermal imager as it is what sets the thermal imaging camera apart from other types of cameras. It also determines critical specs for the imager such as the resolution of the image produced, the spectral range of the lowest to highest micrometers of wavelengths detectable, and the thermal sensitivity (Noise Equivalent Temperature Difference, NETD) which determines the smallest temperature difference detectable by the camera - the lower the number the higher the thermal sensitivity.
●A lens, which precisely focuses infrared waves onto the sensor and determines the camera’s field of view, which is important since the field of view needed can vary widely depending on the camera’s intended use.
●Internal processors, which are the “brains” of the thermal system and translate what the lens and thermal sensor pick up into an image through a complicated algorithmic process. These can also determine special features of the camera like the display palette, fixed vs. moveable crosshairs, and blending.
●Equipment housing, which determines whether the thermal imaging camera is handheld, mounted, embedded within other equipment, etc.
A combination of all of the above components creates a powerful multi-use tool that has been called by many names, including but not limited to: thermal imager, thermal imaging camera, thermal vision camera, and infrared camera.
Is Night Vision the Same as Thermal Vision?
There is often confusion on whether a night vision camera is the same as a thermal vision camera. The answer to that is no; a night vision camera requires some level of light in order to work. Similar to the human eye, night vision cameras use visible light, but they take any of that visible light and greatly magnify it to a degree that makes it easily detectable for our eyes. Thermal vision cameras, or infrared cameras, do not work this way. Because thermal vision cameras use heat rather than visible light, these kinds of cameras can function perfectly even when there is no visible light, giving them a distinct advantage over traditional night vision cameras. Both kinds of cameras are often used in military, law enforcement, and search and rescue operations, which may be where some of the confusion comes from.
Top Thermal Vision Camera Uses and Applications
Thermal vision cameras are very versatile, and are used in a large number of applications that vary greatly in how the thermal imager is actually utilized. The most common use across many professions is gaining the ability to quickly and accurately observe and inspect potentially dangerous objects, machinery, chemicals or animals from a safe distance in a non-invasive and no-contact manner - however, there are many other kinds of uses as well that you may not expect. Here we will list just some of the many applications of infrared cameras both in and out of the workplace.
- Construction and Building Maintenance
○Electrical Maintenance- Thermal imaging cameras can be used by many sub-professions in the electrical field. For example, power line technicians can use the technology to inspect pole-mounted transformers and overhead electrical connections to locate overheating joints and parts so they can eliminate the possibility of potential failures down the line. Thermal imaging cameras can also be used to detect hotspots in electrical wiring and panels, which indicates weakening connections and potential fire hazards (source). The advantage of using thermography in these professions is that it offers the safety of observing these potential electrical faults and hazards from the ground.
○Plumbing- Thermography can be used by plumbers to detect the exact location of hidden water leaks or inspect water damage that may not be visible due to being hidden in the ceiling or walls, under floorboards, and even within concrete foundations. Thermography can also be used in bathrooms or kitchens where plumbing issues might be behind tile or underneath a shower, bathtub, toilet, or sink to pinpoint any water leakage issues (source).
○Insulation Maintenance - In order to maintain the best heating and cooling efficiency in a building, old insulation needs to be inspected routinely for heat leaks or air leaks. Infrared cameras can provide an expert with information on exactly where heat leaks are located so they can be repaired, and can even help assessors determine whether a building needs insulation and where it should go (source).
○Home Inspectors - Thermal imaging cameras are a common tool used by home inspectors to detect issues with the home as far as electrical hazards, inefficient insulation, air drafts, and water damage (source). Using thermal imaging during home inspections offers better accuracy and better risk/damage assessment.
- Mechanical Installations and Commercial Inspections
○Mechanical Inspection and Preventative Maintenance - Infrared cameras offer the best way to inspect mechanical systems and large machinery for functional defects or issues such as unwanted friction between moving parts that could affect the machine’s functionality in the future. An assessor can remain a safe distance away from the machinery while still being able to accurately measure functionality metrics and pinpoint any issues or hazards without having to stop the system from running.
○Refractory Brick Maintenance - Refractory brick, or firebrick, is a type of ceramic block used in the construction of tools or machines that produce extreme heat such as boilers, furnaces, kilns, fireplaces, pizza ovens, or grills. These bricks are essential to maintaining a safe environment around these high-temperature areas by blocking most of the heat produced, even when coming in direct contact with flames. Thermal imagers can help monitor for cracks or faults in the brick, which leads to dangerous levels of heat leakage to the surrounding area. In finding these faults and areas of leakage, thermal imagers can help maintain a much safer environment around these essential but dangerous tools and machinery (source).
○Gas Detection - Many poisonous gasses are actually invisible to the naked eye, such as carbon monoxide, known as an “invisible killer”. Carbon monoxide takes at least 430 lives per year in the U.S., and is the cause of approximately 50,000 emergency room visits a year. Thermal vision cameras can help a professional visualize a gas leak that they would otherwise be unable to see, thus providing an easy route to a solution to stop the gas leak and potentially save lives.
○Industrial Plant Inspections - There are a wide variety of industrial plants, all of which carry relatively high levels of risk when working there, whether due to the size and power of the machinery used or whether the plant uses dangerous chemicals or agents. Because safety is so important in any kind of industrial plant, it is common for infrared imagers to be used for accurate and efficient inspections without having to interfere with daily operations or having to put unnecessary risk on maintenance personnel (source).
○Building Inspections - Thermography and infrared cameras can help a building inspector make sure a structure is up to code, detecting any faults or weaknesses to allow for improvement of the structure for peak safety. Also, detecting faulty spots in the building’s insulation can save a company a lot of money by increasing energy efficiency and limiting resource wasting (source).
- First Responders, Law Enforcement, Security and Military Operations
○Firefighting - An essential tool for firefighters is the thermal vision camera, which allows them to find and rescue people and animals behind walls of smoke, identify an entry point into a flaming building by locating the entrance with the lowest temperature, and pinpoint hotspots for the most efficient fire extinguishing.
○Law Enforcement - Thermal imaging cameras are commonly used in many law enforcement settings, whether it’s surveillance on the street or inside a correctional facility, locating and apprehending suspects on the run via air support, investigating potential crime scenes, or even locating weapons or chemicals being smuggled into prisons or jails (source).
○Military Ops - Thermal vision cameras have become a staple in modern day military tech and gear around the world, whether they are mounted on vehicles or buildings for surveillance, integrated into advanced scopes for quick and accurate aiming, utilized by attack helicopters and aircraft to pinpoint targets on the ground no matter the weather conditions or visibility, or turned into goggles to boots-on-the-ground operations easier and safer no matter what the environment is like.
○Search & Rescue - Infrared cameras are great tools for locating both people and animals in situations like post-natural disaster rescues (hurricanes, tornadoes, earthquakes, etc.), shipwrecks, train or large-scale car accidents, airplane and helicopter crashes, or any missing persons cases. Thermography is so useful in this area because of how it allows the users to locate and extract victims no matter the weather conditions, environment, or lack of visible light. Infraredcameras can also be mounted on drones and piloted remotely through dangerous conditions to locate survivors without risking more lives.
○Security - Thermal imaging cameras are infallible tools for any security surveillance need from high-profile jewelry and luxury stores to at-home personal property security. These types of cameras are great for security because they will always detect an intruder’s heat signature in any weather or in any level of darkness. Intruders cannot hide behind bushes or shrubbery when it comes to thermal vision cameras - they will always pick up their heat signatures.
- Healthcare and Medicine
○Fever Detection- Any human or warm-blooded animal can have their body temperature monitored by thermal imaging cameras. Fever is a very common symptom for many illnesses, and is a natural indicator that the body is fighting off something. The best part about using thermal imagers for fever monitoring is that it’s hands-free - minimizing risk for healthcare workers - and can accurately map the body’s surface temperature in real time without the use of traditional, more invasive clinical thermometers (source).
○Screening and Diagnosis - According to “Medical applications of infrared thermography: A review” in the book Infrared Physics & Technology (Vol. 55, Iss. 4): “IRT has been successfully used in diagnosis of breast cancer, diabetes neuropathy and peripheral vascular disorders. It has also been used to detect problems associated with gynecology, kidney transplantation, dermatology, heart, neonatal physiology, fever screening and brain imaging.”
○Veterinary Medicine - Thermal imaging is a great non-invasive diagnostic screening tool for vets that does not require handling or retraining the animal in question, making it much easier to accurately and safely evaluate animals of all kinds, shapes, and sizes (source).
- Scientific Research and Applications
○Chemical Experiments - Many kinds of chemicals, whether hazardous or not, will have some kind of thermal reaction in experiments. To study the transfer of heat and the distribution of thermal energy during such experiments, it is safest to do so in a no-contact manner. Thermal imaging technology allows for chemists to accurately measure these thermal transactions between chemicals during a reaction without risking their health and safety.
○Wildlife Tracking - In an article on the use of IRT in wild animals and zoos by Sabine Hilsberg-Merz, it is asserted that IR thermography has been a long-time practice of those in the field of wildlife biology to detect, track, and monitor both mammal and bird species. Thermography has even been used successfully in animal censuses (source).
○Bee Rescue - Ever since global awareness has risen about the endangerment of many bee species and the threat their extinction could pose on ecosystems everywhere, people are much more conscious of the summer time beehives and nests that form in their sheds, on the sides of their homes, in shrubbery and trees, or concealed behind paneling or decor. Instead of extinguishing the hives, bee experts and rescuers are hired more often than ever in order to carefully remove the hive, keeping as much comb and as many bees intact as possible, and take it to their own bee sanctuaries for safe keeping. In order to find bee activity in hidden areas like under floorboards or inside of walls, thermal imagingcameras are used to estimate the location and rough size of the hive for smooth removal with as little damage to the surrounding areas as possible.
- Automotive and Aerospace Industries
○Automobile Testing and Safety - Rather than having to deconstruct parts of a car in order to find performance issues, thermal cameras can be used to conduct diagnostic testing in a non-invasive and non-destructive manner. Thermal imaging cameras can also be used to conduct safety tests, including faulty airbag detection (source).
○Aerospace Testing and Safety - Because aerospace equipment is so expensive and disasters can happen from the slightest inconsistency or error, thermal vision cameras are used for problem detecting and functionality monitoring to ensure the greatest accuracy possible. For instance, in order to safely monitor the heat flow in an active jet engine, an infrared camera would be used (source).
- Road Safety Thermal Camera Applications
○Semi and Bus Fleets - Fleet managers know that safety is the number one priority when operating large vehicles carrying heavy loads of valuable goods. In the interest of prioritizing safety, fleets of semis and buses can be fitted with thermal dashcams to help drivers stay aware of their surroundings and alert drivers to potential hazards on the road like wildlife or pedestrians.
○First Responder Vehicles - Because vehicles that are driven by first responders must travel quickly in high-pressure situations, it is important to maximize the safety of our EMTs, firefighters, and policemen and women who risk their lives for our communities every day. Thermal dashcams are a reliable way to highlight roadside risks even at high speeds with plenty of warning.
○Commuter Road Safety - Everyday drivers may not realize just how dangerous driving can be, even when navigating familiar routes to and from work. For the average vehicle, a head-on collision with a wild animal like a deer can be catastrophic - even deadly. Also everyday drivers are much more likely to come across unsuspecting pedestrians who are not paying attention and cyclists who may not be wearing proper reflective gear. Because of this it is highly recommended for anyone with a car to upgrade to have a thermal dashcam. These highly accurate dashcams will unfailingly alert the driver to road hazards from a long distance so that the driver has time to react and take evasive measures.
Best Thermal Cameras and Devices
A top competitor in the rapidly expanding infrared and thermal radiation detector industry is Speedir. As an industry leader that employs experts in the fields of safety and technology, Speedir is the best choice for your thermal camera needs. Offering affordable yet high-quality, state-of-the-art road safety accessories that utilize the powers of infrared technology and artificial intelligence is Speedir’s mission. Explore top products by Speedir below:
●Night Owl: A top-of-the-line thermal night vision camera that uses military-grade, long range infrared technology to ensure drivers can always have enough time to react to potential road safety hazards and make it to their destination safely.
●Night Owl Plus: A thermal night vision camera that is paired with Speedir’s high-tech AI system for maximum safety while driving. Not only is it a thermal dashcam with powerful, accurate infrared sensors and high-quality display capabilities, but it will also audibly alert the driver when hazards are detected and can continuously stay updated via wifi. Take advantage of the “Speedir Thermal” app to activate wireless recording.
●Thermal Mass Fever Screening System: In the face of an unprecedented pandemic, Speedir’s greatest minds put together the most accurate thermal fever screening system that can measure the body temperatures of large masses of people at one time. It’s easy to set up, efficient, and offers a hands-free solution to COVID-19 breakout prevention.