1800: Infrared Discovered
Infrared radiation was discovered by astronomer Frederick William Herschel by using a prism and thermometer. He called the infrared spectrum, which falls between the visible and microwave bands on the electromagnetic spectrum, as "dark heat."
1878: Invention of the Bolometer
In 1878, American astronomer Samuel Pierpont Langley invented the bolometer which measured the resistance change of a platinum strip after exposure to electromagnetic radiation. By the turn of the 20th century, the technology could detect a cow by sensing its heat at 400 meters.
1913: First Civil Application of Thermal Detecting
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While probably developed a few years earlier, the 1912 sinking of the Titanic spurred L. Bellingham to file a patent for a "Means for detecting the presence at a distance of icebergs, steamships, and other cool or hot objects." It used a mirror, bolometer and theromopile, which converts thermal to electrical energy.
1929: First IR Electronic Camera Invented
Hungarian physicist Kálmán Tihanyi, a pioneer of television technology who worked on cathode ray tubes and even plasma television, developed the first infrared-sensitive electronic television camera to detect enemy aircraft for the British. Called the Evaporograph, it was declassified in 1956
1945: Near-Infrared Used by WWII Snipers
IR wavelengths range from 700 nm to 1 mm , though near-infrared, closer to the visible light spectrum, goes from 750 to 950 nm. This method of night vision, which had a range of about 100 m, was used by both Allied and Nazi forces. The Wehrmacht first used the Vampir 1229 (pictured) in the final year of the war.
1947: First Infrared Line Scanner
Texas Instruments and the U.S. militarily developed the line scanner for use on bombers and cargo planes at the start of the Cold War. These measure temperature at a single point, using a rotating mirror assembly to scan a wider area. Back then it was an extremely slow process, taking an hour per image. Modern industrial line scanners, used in temperature-controlled processes, can perform 500 scans/second. The military now uses imagers such as the highly advanced Star SAFIRE III, which capture HD video and have a max range of 25 km.
1978: Microbolometer developed
Prior to the advent of microbolometers, micron-sized version of Langley's invention, thermal imagers needed to be cooled to subzero temperatures to cancel out the thermal noise they were emitting. This was obviously an expensive and delicate process. In the late '70s and eraly '80s, both Honeywell and Raytheon worked on their own versions. Raytheon used a barium strontium titanate for their ferroelectric infared detector and Honeywell implemented Vanadium Oxide. Once the military-funded bolometers became commercialized, they drastically reduced the size, weight and cost of thermal imaging.
1982: Thermogarphy Approved to Detect Breast Cancer
In 1982, the FDA approved the use thermography as an adjunctive screening procedure for the detection of breast cancer. The non-invasive procedure identify if tumors are benign or malignant. When combined with regular exams and mammograms, thermography can help detect 95% of early stage cancers, according to the International Academy of Clinical Thermography.
1987: Thermal Goes Mainstream
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Thermal imaging hit the mainstream when the movie Predator was released. The alien hunter stalked his prey by their thermal radiation. A spokesperson for FLIR, which provided the thermal cameras, says the jungle foliage was sprayed down with cold water before takes to provide more of a contrast with Arnold Schwarzenegger and other actors.
1990s: Fire Departments Adopt Thermal Cameras
A thermal camera can find victims in smoke-filled rooms or pick out hot spots hidden under plywood, making it an essential tool for the modern firefighter. Twenty years ago they were a cost-prohibitive luxury, priced at up to $25,000. Now any firehouse can afford these rugged handheld lifesavers, like the FLIR K2 ($1,345).
2010s: IR-Embedded Testing Equipment
What electrician wants to lug around more gadgets on their belt than Batman? The scaling down of thermal tech allows testing equipment manufacturers, like Fluke, to add thermal vision to their device features. This allows users of 279 FC Thermal Multimeter to troubleshoot faster and validate the fix worked, and to send all the thermal data to the cloud.
2016: First Thermal Smartphone
In 2014, the launch of the FLIR ONE attachment for smartphones gave everyone the ability to discover the infrared spectrum -- for under $300. This past summer, Caterpillar's rugged CAT S60 ($599) began the next phase by embedding a FLIR Lepton camera into the actual phone design. FLIR thinks it won't be long before thermal cameras are as ubiquitous on mobile devices as traditional ones.