High-intensity-discharge lamps

Luminaire types (a) parabolic aluminized reflector (PAR) lamp holder (b) incandescent, compact fluorescent or high-intensity discharge lamp downlight (c) lensed fluorescent lamp luminaire (d) wall-mounted compact fluorescent lamp luminaire (e) wall-mounted high-intensity discharge lamp luminaire (f) roadway luminaire (g) low bay industrial luminaire (h) multi-faceted reflector (MR) lamp (i) pendant sphere. 

The instrumentation required for atomic fluorescence measurements is simpler than that used for absorption. As the detector is placed so as to avoid receiving radiation directly from the lamp, it is not strictly necessary to use a sharp-line source or a monochromator. Furthermore, fluorescence intensities are directly related to the intensity of the primary radiation so that detection limits can be improved by employing a high-intensity discharge lamp. 

Mercury Vapor Lamp- A high-intensity discharge lamp that uses mercury as the primary light-producing element. Includes clear, phosphor coated, and self-ballasted lamps. 

Three decades ago, Greskovich and Chernoch created a new field of application of yttria by producing a laser yttria host-based ceramic material [312]. Yttria is not only used as a solid-state laser material as a laser host crystal for trivalent lanthanide activators, such as Yb + and Nd, but also shows significant potential for luminous pipes in high-intensity discharge lamps and heat-resistive windows. 

The transport of Na through the polycrystalline ceramic arc tubes of high intensity discharge lamps was investigated. The bulk and grain boundary diffusion coefficients and the temperature dependences of the transport processes were determined for Na bulk diffusion (900 to 1200C) ... 

Although most polymers are resistant to corrosion in indoor applications, radiation from indoor fluorescent lighting can cause yellowing in many plastics. Applications exposed to other types of artificial radiation, such as from high-intensity discharge lamps of gamma sterilization, can also subject various polymers to degradation. Prior to use the suitability of a particular resin should be checked. 

Photoreactors are simple in design, consisting of one or more high-intensity discharge lamps with a PTFE KOT tube reactor woimd aroimd one of the lamps. The PTFE tube creates a light-tube effect, which... 

By increasing the lamp s internal operating pressures and temperatures, high-intensity light can be produced. High-intensity discharge lamps are classified as mercury-vapour, metal-halide, or high-... 

Lamps representative of the industry are listed. Variations from manufacturer to manufacturer are likely, especially for the D series of fluorescent lamps and the high-intensity discharge lamps. A high positive value of Ri indicates a small color difference for sample /. A low value of Ri indicates a large color difference. 

There are countless other reactions, many like these and others rather different, but the idea in every case is the same. A sudden flash of light causes an immediate photo-excitation chemical events ensue thereafter. This technique of flash photolysis was invented and applied to certain gas-phase reactions by G. Porter and R. G. W. Nor-rish, who shared with Eigen the 1967 Nobel Prize in Chemistry. High-intensity flash lamps fired by a capacitor discharge were once the method of choice for fast photochemical excitation. Lasers, which are in general much faster, have nowadays largely supplanted flash lamps. Moreover, the laser light is monochromatic so that only the desired absorption band of the parent compound will be irradiated. 

Transparent ITR formulations are also used in refractors for high-intensity-discharge (HID) lamps. The refractors have to be able to withstand the combination of intense light (UV and visible) and heat. In addition, for many applications, such as vandal-resistant refractors, high impact strength is also required. The improved color stability of low- and medium-ITR resins over standard PC and UV-stabilized PC homopolymer is shown in tests with a sample surface temperature of 105 3°C and a 400-W metal-halide lamp (Fig. 14.21). 

Municipal and industrial waste waters, discharged treated or even still untreated, into rivers and coastal waters are the further important source of ecotoxic metals particularly with respect to the burden of aquatic ecosystems. Voltammetry offers an efficient and convenient way for control of the levels of ecotoxic metals[80,81]. The necessary pretreatment is simple and consists in filtration (0,45 pm) and subsequent treatment of the filtrate either by rapid UV-irradiation in a photodigestion device[82] equipped with high intensity mercury lamps (1200 W) with addition of some H2O2 or by a fast wet digestion procedure (see Figure 4). Then follows the simultaneous determination of Cu, Pb, Cd, Zn by DPASV at... 

Mercury. While mercury lamps used to be the standard in high-intensity discharge lighting, their time has passed. This technology has too many drawbacks low LPW, low CRI, poor lumen maintenance, and a blue light that has questionable appeal. In the next 5 to 10 yr, expect sales of mercury lamps to virtually evaporate. 

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