Infrared radiation classification

Radiation thermometers can be sensitive to radiation in all wavelengths (total-radiation thermometers) or only to radiation in a band of wavelengths (spectral-radiation thermometers). Thermocouple and thermopile junctions or a calorimeter are the usual detectors in a total-radiation thermometer. For spectral systems, the classification is normally based on the effective wavelength or wavelength band used—as determined, for example, by a filter, which allows only near-monochromatic radiation to reach the detector, or by the use of a detector sensitive only to radiation in a specific wavelength band. Radiation thermometers utilize the visible portion of the radiation spectrum, infrared thermometers or scanners measure infrared radiation, and spectroscopic thermometers operate with radiation that is normally of shorter wavelength than the other two methods. 

A point in the star-forming part of the Orion nebula that emits infrared radiation (but no visible radiation, probably because it is scattered by the dense dust of the nebula). It is thought to be a young near main-sequence star of type B spectral classification, and one of the youngest stars so far observed. 

Burns result from exposure to extremes of heat. The lowest temperature at which a burn can occur has been estimated to be 44 °C (111 °F) (Moritz and Henriques 1947). Burns may be of industrial, domestic or environmental origin. Industrial burns are common (Moritz and Henriques 1947 Cason 1981) and may have characteristic occupational patterns (Renz and Sherman 1994 Woods et al. 1996). Apart from direct contact with hot objects or radiation heat [infrared radiation (IR)], accidental exposure to laser energy may cause thermal destruction through absorption by skin chromophores such as melanin and haemoglobin, well known from the therapeutic application of different lasers in dermatology. Classification of burns is based on the depth of the burn as first, second, or third degree (Table 1) (Burke and Bondoc 1993). 

Numerous physical mechanisms are usable for detection of infrared radiation, and thus there are numerous different detectors. This section lists some more important types of infrared detectors. The key for the presented classification is the basic effect used for the detection of IR radiation. 

Collision-induced electronic spectra have many features in common with rovibrotranslational induced absorption. In this Section, we take a look at the electronic spectra. We start with a historical note on the famous forbidden oxygen absorption bands in the infrared, visible and ultraviolet. We proceed with a brief study of the common features, as well as of the differences, of electronic and rovibrotranslational induced absorption. Recent work is here considered much of which was stimulated by the advent of the laser - hence the name laser-assisted collisions. The enormous available laser powers stimulated new research on laser-controlled, reactive collisions and interactions of supermolecules with intense radiation fields. In conclusion, we attempt a simple classification of various types of electronic collision-induced spectra. 

Objects that radiate mainly at infrared wavelengths may do so because of their low temperature by astronomical standards. Objects that fall in this category start with stars of spectral classifications of K or cooler extending down the newly designated spectral classification of L. The sub-stellar classification ofBrown Dwarf links stars generating energy by nucleosynthesis to planets such as the giant and terrestrial planets in our own solar system. The planets such as the earth radiate like blackbodies at their surface... 

It is also useful to consider using the Current U.S. Classification system to search for related materials. These numbers are somewhat arbitrary, but can be better understood by searching the USPTO web site. For example, all photochemical patents dealing with microencapsulation are in class 430/138 those involving infrared exposure are 430/944, and those using laser beams 430/945. Class 281.1 contains radiation sensitive composition comprising ethylenically unsaturated compounds. 

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