Nichrome radiation source

The main sources of infrared radiation used in spectrophotometers are (1) a nichrome wire wound on a ceramic support, (2) the Nernst glower, which is a filament containing zirconium, thorium and cerium oxides held together by a binder, (3) the Globar, a bonded silicon carbide rod. These are heated electrically to temperatures within the range 1200- 2000 °C when they will glow and produce the infrared radiation approximating to that of a black body. 

A Nernst glower is a cylinder of zirconium and yttrium oxides that emits IR radiation when heated to a high temperature by an electric current. Electrically heated spirals of nichrome wire also serve as Inexpensive IR sources. 

Nichrome A nickel/chromium alloy when incandescent, a source of infrared radiation. 

Source. This usually consists of a filament or rod of some refractory material, heated to a temperature of around 1500 K so as to emit infrared radiation. The Globar is probably the most common source of mid-infrared radiation, consisting of synthetic silicon carbide. This usually has to be water-cooled, however. Filament (Nernst), and nichrome wires are also popular—and may not require water cooling. Water-cooled sources should deliver a higher and more stable output, which is better suited to quantitative applications. 

The sources used for mid-IR are heated rods, such as a nichrome ribbon or a globar, which is a rod of silicon carbide. The Opperman source is a rhodium heater in an alumina tube packed with alumina and zirconium silicate. When heated to above 1000°C, these sources emit energy over a wide range, resembling a black-body radiator with a maximum intensity at about 1000 cm For NIR, tungsten or trmgsten halogen lamps are used. 

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