Incandescent lamps

Hafnium is used in gas-filled and incandescent lamps, and is an efficient getter for scavenging oxygen and nitrogen. 

Incandescent Lamps, Electronic Tubes, and Resistance Elements. Articles fashioned in any form from molybdenum and tungsten usually fall within the bounds of powder metallurgy. These metals normally are first produced as a powder. Both molybdenum and tungsten are used as targets in x-ray tubes, for stmctural shapes such as lead and grid wires in electron tubes, and as resistance elements in furnaces. 

Refractory metals are associated with powder metallurgy because these metals are not easily melted. Therefore in smelting the ores, the metal is recovered in powder form rather than melted. Refractory metals are used mainly to produce filament wire for incandescent lamps. 

Tungsten with the addition of as much as 5% thoria is used for thermionic emission cathode wires and as filaments for vibration-resistant incandescent lamps. Tungsten—rhenium alloys are employed as heating elements and thermocouples. Tantalum and niobium form continuous soHd solutions with tungsten. Iron and nickel are used as ahoy agents for specialized appHcations. 

Dispersion-strengthened copper is made by dispersing a thoria or alumina phase through copper powder. The resulting P/M product retains its strength at elevated temperatures. It is used, for example, as the conductor or lead wine that supports the hot filament inside incandescent lamps. 

Fig. 11. Energy distributions of CIE standard illuminant A, a tungsten incandescent lamp a cool white fluorescent lamp E and CIE standard illuminant...

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). ... 

Eady fusing systems, such as that used in the Xerox 914, employed radiant heat produced by incandescent lamps. Black toner is an extremely good... 

In LT motors, a standard test finger as shown in Figure 11.7 is used, connected by an incandescent lamp to one pole of a supply of at least 40 V, the other pole of the supply being connected to the parts intended to be live in normal service. All parts must be connected electrically. The lamp should not glow when an attempt is made to touch the bare live parts or insufficiently insulated parts. Insufficiently insulated parts may be covered with a metal foil connected to tho.se parts that are live in normal service. Conducting parts covered with varnish or enamel only or protected by oxidation or by a similar process may be considered as insufficiently insulated. In HT motors, the clearance is verified with the minimum clearance required to withstand the dielectric test as in Section 11.4.8,... 

The original drive for the development of modem carbon fibers, in the late-1950s, was the demand for improved strong, stiff and lightweight materials for aerospace (and aeronautical) applications, particularly by the military in the West. The seminal work on carbon fibers in this period, at Union Carbide in the U.S.A., by Shindo, et al, in Japan and Watt, et al, in the U.K., is well-documented [4-7]. It is always worth pointing out, however, that the first carbon fibers, prepared from cotton and bamboo by Thomas Edison and patented in the U.S.A. in 1880, were used as filaments in incandescent lamps. 

The electrical age was built on the discovery in the early 1830s, independently by Joseph Henry (1797-1878) in America and Michael Faraday (1791-1867) in England, of electromagnetic induction, which led directly to the invention of the dynamo to generate electricity from steam-powered rotation. It came to fruition on New Year s Eve, 1879, when Thomas Edison (1847-1931) in rural New Jersey, after systematic and exhaustive experiments, made the first successful incandescent lamp, employing a carbonised filament made from some thread taken from Mrs. Edison s sewing cabinet. The lamp burned undimmed for 40 h, watched anxiously by Edison and some of his numerous collaborators. This lamp was ideal for... 

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... 

R = recorder, I = integrator, E = detector, Pr = sample (TLC plate), S = mirror, M = monochromator, L = lamps (incandescent lamp , deuterium lamp 0 and mercury lamp G), FI = cutoff filter. 

II should noi be overlooked that platinum has played a crucial role in ihe development of many branches of science even though the amounts of metal involved may have been small. Reliable Pt crucibles were vital in classical analysis on which the foundations of chemistry were laid. It was also widely used in the development of the electric telegraph, incandescent lamps, and thermionic valves. 

States also began to look at new products. Massachusetts promulgated legislation requiring its state energy office to set standards for fluorescent and incandescent lamps, and introduced legislation requiring standards for electric motors. Transformers were later added to the Massachusetts list. 

A number of new technology promotion options are being explored in the lighting area. Work is undeiway on market transformation programs based on bulk procurement for improved efficacy incandescent light bulbs and for compact fluorescent lamps and fixtures. For incandescent lamps, adaptations of the infrared reflective lamp coating that is already in use on reflector bulbs are encouraged by the EPAct requirement. 

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