Table of ContentsPhysics of ThermographyTypes of ThermographyMedical ThermographyLimitationsThermographic CamerasInfrared thermography is a non-contact imaging technique for visualizing infrared radiation. The IR radiation emitted by an object has a different intensity depending on its surface temperature. An infrared camera detector detects infrared radiation and electronically displays a visual image of temperatures – a thermal image or thermogram. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”? Get the original essay Since infrared radiation is emitted by all objects whose temperature is above absolute zero according to the law of body radiation black, thermography allows you to see your environment with or without visible lighting. The amount of radiation emitted by an object increases with temperature; thermography therefore makes it possible to observe temperature variations. When viewed through a thermal camera, hot objects stand out well against colder backgrounds. There are three types of thermography: liquid crystal thermography (LCT), infrared thermography (IRT) and microwave thermography (MWT). The non-invasive and high-resolution characteristics of thermographic systems make them valuable diagnostic and therapeutic aids. Before 1800, the existence of the infrared part of the electromagnetic spectrum was not even suspected. The original importance of the infrared spectrum as a form of thermal radiation is perhaps less obvious today than it was when it was discovered in 1800 by Sir William Herschel during his search for a new material optical. Sir William Herschel (1738-1822), astronomer royal to King George III of England – and already famous for his discovery of the planet Uranus – was looking for an optical filter material to reduce the brightness of the image of the Sun in telescopes during solar observations. As the blackened thermometer slowly moved along the colors of the spectrum, the temperature readings showed a steady increase from the purple end to the red end. The Italian researcher Landriani, in a similar experiment in 1777, observed almost the same effect. It was Herschel, however, who was the first to recognize that there must be a point where the heating effect reached a maximum and that measurements confined to the visible part of the spectrum were unable to locate this point. When Herschel revealed his discovery, he called this new part of the electromagnetic spectrum the "thermometric spectrum." The radiation itself he sometimes called "black heat" or simply "invisible rays." "However, it was not Herschel who originated the term "infrared." The word did not begin to appear in print until about 75 years later, and it is still unclear who came up with it. Originally in the late 1950s and 1960s, Texas Instruments, Hughes Aircraft, and Honeywell developed single element detectors that scanned scenes and produced linear images. The military had control over this technology because. that it was expensive and had sensitive military applications These basic detectors led to the development of modern thermal imaging The vidicon pyroelectric tube was developed in the 1970s by Philips and EEV and became the heart of a. product first used by the Royal Navy to fight fires on board ships In 1978, Raytheon's R&D group, then part of Texas Instruments, patented ferroelectric infrared detectors that used carbon.barium strontium titanate, or BST, which is the material that covers the thermal imager sensor. Raytheon first demonstrated this technology to the military in 1979. In the late 1980s, the federal government awarded High Density Network Development, or HIDAD, contracts to Raytheon and Honeywell for development of the thermal imaging technology for practical military applications. Raytheon later commercialized BST technology. Honeywell developed vanadium oxide (VOx) microbolometer technology. Later, federal programs, such as LOCUSP (Low-Cost Uncooled Sensor Program), funded both companies to develop their thermal imaging technologies into equipment systems, including rifle sights and drivers' viewers. After the 1991 Gulf War, production volumes increased and costs decreased, so the use of thermal imaging was introduced in municipal firefighting services. In late 2004, Raytheon's commercial infrared division was sold to L-3 Communications. Meanwhile, the Honeywell microbolometer was granted a patent in 1994. Boeing, Lockheed-Martin (which sold its infrared business to British Aerospace, or BAE) and others licensed Honeywell's VOx technology for infrared detectors for military applications. Thermal imagers based on BST and microbolometer technologies are now available for non-military applications. In fact, thermal imaging has expanded for use in law enforcement, commercial and industrial applications, security, transportation, and many other industries. Bullard introduced its first thermal imager specifically designed for firefighting in 1998. The American Society of Non-Destructive Testing developed and approved standards for teaching thermal imaging courses in 1992. These courses are called levels I, II and III. In the early 2000s, prices for infrared cameras continued to fall and cameras became smaller, so new uses for the construction industry began to emerge in earnest. In 2006, thermal imaging using infrared cameras by home inspectors and contractors became more common. In 2008, the International Association of Certified Home Inspectors – InterNACHI – developed its Infrared-Certified® program to teach home inspectors how to use infrared cameras in a wide variety of areas. building inspection requests. Since then, InterNACHI has been the leading association of home inspectors promoting and teaching its members the effective use of thermal imaging. Physics of Thermography Infrared ray is a kind of electromagnetic wave with a frequency higher than radio frequencies and lower than visible light frequencies. . The infrared region of the electromagnetic spectrum is typically between 0.77 and 100 μm for convenience. It is often divided into near infrared (0.77 to 1.5 μm), mid infrared (1.5 to 6 μm), and far infrared (60 to 40 μm) and far infrared. (40 to 100 μm) Infrared rays are radiated spontaneously by all objects having a temperature above absolute zero (-459.67). The law of black body radiation is the actual principle that works in thermography. A black body is an idealized physical body that absorbs any incident electromagnetic radiation. Because of this perfect absorptivity at all wavelengths, a black body is also the best possible emitter of thermal radiation, which it emits incandescently in a continuous spectrum and