The first known thermocouple capable of detecting a person from ten meters away was created in 1833 by Macedonio Melloni, a scientist who worked alongside Leopoldo Nobili to refine the Seebeck effect into a practical instrument. This early device did not produce a picture but rather a reading that proved invisible heat existed beyond the red end of the visible spectrum. Sir William Herschel had discovered this radiation in 1800, but it took decades for engineers to translate that discovery into a tool that could see living things in the dark. By 1901, Samuel Pierpont Langley had improved the bolometer to such a degree that it could detect radiation from a cow from four hundred meters away with a sensitivity of one hundred thousandths of a degree Celsius. These early pioneers laid the groundwork for a technology that would eventually allow humans to see the world through the lens of temperature rather than light.
War and The Night Vision
The first electronic television camera sensitive to infrared radiation was invented in 1929 by Hungarian physicist Kálmán Tihanyi for anti-aircraft defense in Britain. While Tihanyi's work was theoretical, the first American thermographic camera was developed in 1947 by the US military and Texas Instruments, a device that took one hour to produce a single image. The military needed to see enemies in the dark, and the first British infrared linescan system, known as Yellow Duckling, emerged in the mid-1950s to track submarines by their wake. Although Yellow Duckling failed to track submarines, it became the foundation of military IR linescan for land-based surveillance. By 1969, Michael Francis Tompsett at English Electric Valve Company patented a camera that scanned pyro-electronically, reaching a high level of performance after several breakthroughs during the 1970s. Tompsett also proposed an idea for solid-state thermal-imaging arrays, which eventually led to modern hybridized single-crystal-slice imaging devices used today.The First Commercial Image
The first commercial thermal imaging camera was sold in 1965 for high voltage power line inspections, marking the transition of infrared technology from the battlefield to the industrial sector. This device allowed maintenance technicians to locate overheating joints and sections of power lines, which are a sign of impending failure. The first civil sector application of IR technology may have been a device to detect the presence of icebergs and steamships using a mirror and thermopile, patented in 1913 by L. Bellingham. This was soon outdone by the first accurate IR iceberg detector, which did not use thermopiles, patented in 1914 by R.D. Parker. G.A. Barker proposed to use the IR system to detect forest fires in 1934, and the technique was not genuinely industrialized until it was used to analyze heating uniformity in hot steel strips in 1935. These early applications proved that the technology could save lives and money by preventing disasters before they occurred.