Incandescent filament lamp

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 Superseded by BS EN 60432-1 2000, but remains cuiTcnt... 

Fig.4.3. Experimental arrangement for investigation of pyrolysis of molecules by the method of semiconductor sensors 1 - reaction vessel, 2 - quartz slab with a ZnO film (sensor), 3 - filter, 4 - contacts, 5 - incandescent filament, 6 - thermocouple, 7 - cell with a substance, 8 - lamp - manometer, 9 - pin, 10 - flask, 11 - sealing bulkhead, 12 - trap, 13 - thermostat.

The carbon filament lamp vAiich was developed in parallel at the beginning of this century was always several times as expensive in use as an Auer incandescent mantle. As a result, this first use of the rare eaurth elements achieved great economic success and thanks to his capabilities Auer von Welsbach played a major role in this worldwide achievement. He was in the position to survive the extraordinarily corplicated and obstinately pursued patent battles. 

Niobium and tantalum suddenly received considerable attention about the year 1905 as possible materials for the filaments of incandescent electric lamps in place of the carbon filament then in use The metals were then prepared in the pure state for the first time by Dr Werner von Bolton,6 and their properties were examined. Niobium was found to be unsuitable for the purpose in view, but tantalum proved to be satisfactory. Tantalum lamps were manufactured in large quantities between the years 1905 and 1911, when the metal was displaced by the electrically more efficient tungsten. 

The photostability of vitamin solutions under the influence of various light sources was studied by DeMerre and Wilson (96). The results of this study indicated that the rate of photolysis of vitamin is influenced by the intensity as well as the type of light source used. The loss in potency of vitamin B solution was about 10% for every 30 minutes of exposure to bright natural daylight of 8000 foot-candles. When the same solution was irradiated with a 300 W incandescent reflector-type filament lamp, the losses after two hours of exposure were 11% at 7000 foot-candles and 45% at 14,000 foot-candles. 

There are two commonly used sources of light in UV-visible absorption spectrophotometry, hydrogen or deuterium discharge lamps and incandescent filament... 

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.

Discharge lamps do not produce light by means of an incandescent filament but by the excitation of a gas or metallic vapour contained within a glass envelope. 

Carbon fibers, thought by many to be a relatively new material, actually have a long history as evidenced by the issuance of the first patent for incandescent electric lamp filaments (carbon fibers). The patent was issued to Thomas Edison in 1892. Hiram Maxim (the inventor of the machine gun, among other things) was issued a process patent for carbon fibers in 1899. Prior to the 1950s, these fibers had marginal strength and were used primarily for their electrical properties. 

Discharge lamps do not produce light by means of an incandescent filament but by the excitation of a gas or metallic vapour contained within a glass envelope. A voltage applied to two terminals or electrodes sealed into the end of a glass tube containing a gas or metallic vapour will excite the contents and produce light directly. Fluorescent tubes and CFLs operate on this principle. 

To find a satisfactory element material, Edison was reputed to have tried more than 1600 kinds of materials ( paper and cloth, thread, fish line, fiber, celluloid, boxwood, coconut shells, spruce, hickory, hay, maple shavings, rosewood, soft dry wood rotted by fungal attack (punk), cork, flax, bamboo and incredibly the hair out of a red-headed Scotsman s beard ). Until eventually, Edison hit on the idea of carbonizing a loop of ordinary cotton thread, which glowed in a vacuum for more than half of that eventful day of 21 October, 1879. This filament was later replaced by carbonized Bristol cardboard that burned for 170 hours. The incandescent electric lamp had arrived. 

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