Thermal cameras, also known as thermal imaging cameras or thermal imagers, are used across various industries worldwide. They're incredibly versatile devices that can help promote safety and efficiency in the workplace.
What is a Thermal Camera?
A thermal imaging camera captures and creates a thermal image by translating or converting the thermal energy emitted from the object into visible light, or light that can be seen by the human eye. The thermal image formed on the display is called a thermogram and is achieved through thermography. The thermogram represents an object's temperature.
The technology behind thermal cameras was first developed for tactical military applications. The first infrared-sensitive camera was invented in 1929 by Hungarian physicist Kalman Tihanyi. Thermal imaging was then used as night vision for British anti-aircraft defense after the First World War. Thermal imaging was also incorporated into early German night vision technology to detect enemies during the Second World War.
But, its history can be tied to the discovery of infrared in the 1800s by Sir Frederick William Herschel, an astronomer, and to the invention of the first bolometer—a device that can detect minute differences in temperature—by Samuel P. Langley.
Modern-day thermal cameras usually come in the form of a handheld device. They can also come in larger sizes and are often mounted on tripods. This type of configuration is commonly found in airports and laboratories.
What Do Thermal Cameras See?
Visible light is a small part of the electromagnetic spectrum, and it's the only light that's directly visible to the human eye. The visible light spectrum has wavelengths within the 380 to 700-nanometer range.
Infrared radiation or IR represents a larger chunk of the electromagnetic spectrum. However, unlike visible light, it can't be directly perceived by the human eye. This is because the infrared wavelengths are longer than the ones emitted by visible light. This is where special equipment, in the form of a thermal imaging camera or an infrared camera, comes in.
All objects have the ability to absorb and reflect energy. Some of these objects can also transmit energy at varying levels. They give off different levels of heat energy or cold energy, which is detected by thermal imagers. This, in turn, will be translated into thermal images.
On a thermographic display, warmer components will show up as reds, oranges, or yellows. Cooler components are seen as purples and blues. The green color that can be distinguished on the display indicates that a particular area or component is roughly at room temperature.
Simply put, a thermal camera is equipped with a heat sensor that's attached to a special type of lens. This lens captures and focuses infrared energy onto detectors that create a pattern or a thermogram. This thermogram is then converted into a thermal image that can then be seen by the human eye. Thermal imaging cameras are not affected by light or the lack thereof, allowing them to still produce an image even in dark or low light conditions.
What to Look for in Thermal Imaging Cameras
There are several factors to consider before purchasing a thermal camera, aside from cost and quality. Whether you're opting for a simple point-and-shoot thermal imager or a more high-end device typically used for research, it's always important to consider a thermal camera's detector resolution and thermal sensitivity.
The former refers to the number of pixels a thermal camera can manage to fit in the frame. The rule of thumb is that the more pixels it can accommodate, the more detailed the thermal image is going to be. Thermal sensitivity refers to the camera's ability to measure the smallest degree of temperature change.
The kind of thermal camera you should choose ultimately depends on the applications it will be used for. Do you need a portable infrared camera or a fixed mount infrared thermometer? You also have to consider other factors, such as the camera's temperature range, focus, available lens options, supported file formats, and color palettes, among other features and specs.
Most Popular Thermal Camera Uses
Thermal imaging cameras have a wide range of applications. Aside from industrial uses, including below-ground applications in mining and the petrochemical industry, here are some of the most popular uses for thermal imagers:
Thermal imaging cameras can be used to identify a number of property issues, such as problems with thermal insulation or electrical hazards that can cause a home to become less energy efficient. They can enable the quick assessment of a building's structure and the identification potential concerns, such as heat loss and damages on your cooling or heating systems.
Thermal imaging is a non-invasive way to detect hidden water and moisture issues. While it cannot actually "see" moisture problems in the walls, a thermal camera can detect temperature differences and moisture patterns in walls and ceilings. It can also be used to spot flooding and leaks.
What's great about this equipment is it can cover up to a certain distance, making it easier to spot a potential problem even in hard-to-reach or potentially dangerous areas.
Thermal cameras have recently become an important diagnostic tool for HVAC inspections. Given that HVAC systems can be quite complex, troubleshooting or detecting issues can be difficult without the proper tools. If left unchecked, these problems may quickly escalate and lead to more costly repairs.
By using a thermal imaging camera, HVAC technicians can quickly and efficiently spot air leaks, locate duct work, or identifying water leaks or moisture in the HVAC system.
When it comes to electrical maintenance, thermal cameras have extensive applications. Electricians can use thermal imaging to detect areas that are at risk of overheating, loose connections or contact problems, heat signatures associated with high electrical resistance, and overloaded circuits. Thermal cameras can also be used for regular thermal surveys and to monitor electric distribution.
Pests can be difficult to discover without the right tools. Thermal imaging devices are non-intrusive solutions that can help detect and display the heat signature of pests. To clarify, these thermal imaging devices can't see through walls to spot pests that are hiding inside a wall. However, a thermal camera can identify the differences in temperature on the surface of a wall.
For instance, while a thermal camera can't "see" moving termites, it can reveal a termite nest by way of the heat signature and, consequently, the difference in temperature that the nest generates.
With thermography, building maintenance professionals and pest control services can quickly and efficiently find the nest, all while minimizing any damage to the property during the extraction.
Drone (Field Inspections)
Thermography drones have become especially useful in the industrial and construction sectors. They can be utilized in conducting a thermographic inspection of an inaccessible structure or for checking larger photovoltaic systems. Professionals in the energy industry can also use them to check for the presence of gas, monitor tank levels, and identify any hot spots on machinery.
These drones are also utilized to monitor large areas, give an overview of fire spread, and locate victims in areas with little to no visibility.
Thermal imaging cameras can have several marine applications. They can be used in tandem with collision detection systems when sailing in conditions with little to zero visibility. When operated underwater, thermal imaging systems will lose some of their effectiveness. However, there are heat detection cameras that are being manufactured according to marine-grade specifications.
Driving at Night
Night vision cameras (like Nightride dash cam) allow for improved visibility, especially in low-light or dark areas. This thermal imaging technology can help minimize accidents that are usually attributed to poor visibility, particularly when depth perception, color recognition, and peripheral vision are compromised.
One of the better known applications for thermal cameras is as a diagnostic tool for auto repairs and vehicle maintenance. These can help mechanics quickly spot issues that aren't immediately visible. A thermal camera can be used to check whether or not an electrical component is functioning properly. It can also be utilized to identify system leaks, failed gaskets, and damages in other components.
Thermal cameras can help save lives. They can be relied on by first responders in making informed decisions. As part of search and rescue gear, a thermal camera can be used by firefighters or rescuers to help them navigate smoke-filled or dark surroundings. They can also allow for the assessment of an area's temperature from a safe distance.
Moreover, this equipment can help detect a fire's hot spots or sources of ignition, the location of trapped victims, and other potential dangers during wildfires, structural fires, or mountain searches.
Body Scanner (Fever Detection)
One of the most common uses of thermal imaging cameras is as a body scanner. When properly used, thermal cameras can accurately measure an individual's surface skin temperature. Thermal imaging systems, such as those produced by FLIR Systems, have also been used by several countries worldwide during epidemics, such as the SARS epidemic in 2003.
A thermal imaging system can be used to assess the temperature of patients to identify who needs more medical attention or who needs to be isolated.
Animal Health Screening
Thermal imaging devices also have versatile applications when it comes to animal health screening. Veterinarians can use these cameras to identify inflammation in domesticated animals such as horses, cows, and dogs. Mastitis, a potentially fatal infection in the cow's mammary gland, can be easily located with the help of thermography.
Moreover, thermal imaging allows for better animal health monitoring. It can be used to assess an animal's stress levels by way of monitoring their heat stress. Other health issues that can be located using thermal imaging include nerve damage, skeletal problems, and injuries.
Hunting enthusiasts can rely on thermal imaging systems to locate warm-blooded animals or elusive wildlife and to spot non-targets, especially in areas with poor visibility. Aside from being utilized for hunting, they can be valuable in locating nocturnal or elusive wildlife for photography, environmental monitoring, and wildlife conservation.
For conservationists, thermal cameras can help give the detailed observations needed to gain a better understanding of animals and their behavior. Whether in the form of a drone, a handheld camera, or a mounted thermal camera, this technology can help bring valuable environmental insights for both hunters and conservationists.
Thermal cameras can also be used to bolster security in low-light areas or locations with poor visibility. When paired with CCTV setups, thermal imaging cameras can greatly improve the protection and return on investment of homes and other buildings.
Given its military roots, thermal imaging cameras are still widely used today in defense systems. FLIR or forward-looking infrared cameras are used in military operations and aircraft. They're also used to help guide soldiers even in complete darkness.
Aircraft and vehicle mechanics also use thermal imaging as a non-intrusive way of locating faulty electrical or mechanical components.
Policies and law enforcement agencies can work smarter with thermal imaging systems. These allow them to efficiently deal with unpredictable situations. They also enable officers to respond to delicate situations without compromising their safety.
They can be used as surveillance tools in areas with poor visibility or challenging environmental conditions. They’re also utilized for radiation and explosives detection.
Thermal imaging cameras come in various shapes and sizes. Some are small, portable devices. Some are unmanned drones used to help enhance public safety. There are also larger units that can be used in chemical detection and identification.