Incandescent tungsten-filament lamps

AMD 1 Incandescent lamps - Safety specifications. Tungsten filament lamps for domestic and similar general lighting purposes (AMD 9115) dated January 1998. Superseded by BS EN 60432-1 2000, but remains cuiTcnt... 

Figure 5.13 Emission intensity of blackbody radiation at various temperatures as a function of wavelength 3000 K is equivalent to a tungsten filament lamp (an incandescent lamp) 6000 K is equivalent to a xenon arc lamp.

Clearly, standardized light sources are desirable for color matching, particularly in view of the phenomenon of illuminant metamerism described below. Over the years CIE has defined several standard illuminants, some of which can be closely approximated by practical sources. In 1931 there was Source A, defined as a tungsten filament incandescent lamp at a color temperature of 2854 K. Sources B and C used filtering of A to simulate noon sunlight and north sky daylight, respectively. Subsequently a series of D illuminants was estabUshed to better represent natural daylight. Of these the most important is Illuminant E). ... 

Uranium dioxide occcurs in nature as mineral uraninite. It is used in nuclear fuel rods for reactors. Also it is used in large incandescent lamps for photography or motion pictures and is connected to the tungsten filaments to prevent sudden surges of current. 

Two light sources are commonly used in this spectral domain. An incandescent lamp made from a tungsten filament housed in a glass envelope is used for the Visible... 

Sources of ultraviolet radiation include (a) tungsten-filament incandescent lamps (b) tungsten-iodine cycle lamps with quartz envelopes (c) mercury-vapor lamps and (d) the zinc discharge lamp. Odier types are available, but enjoy only limited application. The hydrogen or deuterium lamps are used in the laboratory, but are delicate and costly for process uses. 

Every substance at a finite temperature continually radiates energy, with a distribution (spectrum) which depends on the surface temperature. Figure 5.1 shows these spectra for two different temperatures 5800K (the surface temperature of the sun) and 3000K (the surface temperature of the tungsten filament in a household halogen lamp, which is a special kind of incandescent light bulb). 

Quartz-iodine lamp A tungsten filament high-intensity incandescent lamp which contains iodine in a quartz envelope. Used primarily as a source of visible light. 

FIGURE 6.7. SEM image of a non-sag tungsten filament (a) before use, (b) after several hundred hours of operation in a 60-W incandescent lamp. Facetting of the originally round filament occurred due to evaporation of tungsten at the high operation temperature (2400-2500 °C). 

The working temperature of tungsten-filament incandescent lamps lies between 2200 and 3000 K. Therefore, they emit light mostly in the visible and infrared parts of the spectrum. Such a source of radiation may be useful in photoreactions of coloured chromophores, for example in the photodissociation of bromine or chlorine molecules to initiate photohalogenation reactions (Section 6.6.1). 

United States each month in the manufacture of incandescent lamps. Tin- "tungar rectifier, a charging device using a tungsten filament in an argon hulh, is also rapidly Iweouiing popular. 

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