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Encyclopedia > Fluorescent lamp
Fluorescent lamps
Fluorescent lamps
Assorted types of fluorescent lamps. Top, two Compact fluorescent lamps, bottom, two regular tubes. Matchstick shown for scale.
Assorted types of fluorescent lamps. Top, two Compact fluorescent lamps, bottom, two regular tubes. Matchstick shown for scale.
Typical F71T12HO 100W bi-pin lamp used in tanning beds. Note (Hg) symbol indicating it contains mercury. In the US this symbol is now required on all fluorescent bulbs that contain mercury.
Typical F71T12HO 100W bi-pin lamp used in tanning beds. Note (Hg) symbol indicating it contains mercury. In the US this symbol is now required on all fluorescent bulbs that contain mercury.

A fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. Image File history File linksMetadata Size of this preview: 800 × 533 pixel Image in higher resolution (3504 × 2336 pixel, file size: 2. ... Image File history File linksMetadata Size of this preview: 800 × 533 pixel Image in higher resolution (3504 × 2336 pixel, file size: 2. ... Image File history File links Download high-resolution version (2592x1944, 1341 KB) Description: Verschiedene Leuchtstofflampen Source: selbst fotografiert Photographer: Christian Taube Chtaube 20:09, 9 Apr 2005 (UTC) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Fluorescent lamp... Image File history File links Download high-resolution version (2592x1944, 1341 KB) Description: Verschiedene Leuchtstofflampen Source: selbst fotografiert Photographer: Christian Taube Chtaube 20:09, 9 Apr 2005 (UTC) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Fluorescent lamp... Low-energy light-bulb redirects here. ... Image File history File links Tanninglamp. ... Image File history File links Tanninglamp. ... Germicidal lamps are simple low pressure mercury vapor discharges in a fused quartz envelope. ... Electricity (from New Latin ēlectricus, amberlike) is a general term for a variety of phenomena resulting from the presence and flow of electric charge. ... This article is about the element. ... This article is about the chemical use. ... For other uses, see Ultraviolet (disambiguation). ... Green screen A phosphor is a substance that exhibits the phenomenon of phosphorescence (sustained glowing after exposure to light or energised particles such as electrons). ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... For other uses, see Light (disambiguation). ...


Unlike incandescent lamps, fluorescent lamps always require a ballast to regulate the flow of power through the lamp. However, a fluorescent lamp converts electrical power into useful light more efficiently than an incandescent lamp; lower energy costs offsets the higher initial cost of the lamp. While larger fluorescent lamps have been mostly used in large commercial or institutional buildings, the compact fluorescent lamp is now being used as an energy-saving alternative to incandescent lamps in homes. Compared with incandescent lamps, fluorescent lamps use less power for the same amount of light, generally last longer, but are bulkier, more complex, and more expensive than a comparable incandescent lamp. The incandescent light bulb uses a glowing wire filament heated to white-hot by electrical resistance, to generate light (a process known as thermal radiation). ... An automotive (ignition system) ballast resistor An electrical ballast (sometimes called control gear) is a device intended to limit the amount of current flowing in an electric circuit. ... Low-energy light-bulb redirects here. ...

Contents

History

Physical discoveries

The history of the fluorescent lamp begins with early research into electrical phenomena. By the beginning of the 18th century, experimenters had observed a radiant glow emanating from partially evacuated glass vessels through which an electrical current passed. Little more could be done with this phenomenon until 1856 when a German glassblower named Heinrich Geissler (1815–1879) created a mercury vacuum pump that evacuated a glass tube to an extent not previously possible. When an electrical current passed through a Geissler tube, a strong green glow on the walls of the tube at the cathode end could be observed. The article on electrical energy is located elsewhere. ... Look up current in Wiktionary, the free dictionary. ... Heinrich Geissler (May 26, 1814 - January 24, 1879) was a German physicist. ... Look up Vacuum in Wiktionary, the free dictionary. ... The Geissler tube is a glass tube for demonstrating the principles of electrical discharge. ...


Because it produced some beautiful light effects, the Geissler tube was a popular source of amusement. More important, however, was its contribution to scientific research. One of the first scientists to experiment with a Geissler tube was Julius Plücker (1801–1868) who systematically described in 1858 the luminescent effects that occurred in a Geissler tube. He also made the important observation that the glow in the tube shifted position when in proximity to an electromagnetic field. Julius Plücker. ... Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, composed of the electric field and the magnetic field. ...


Inquiries that began with the Geissler tube continued as even better vacuums were produced. The most famous was the evacuated tube used for scientific research by William Crookes (1832–1919). That tube was evacuated by the highly effective mercury vacuum pump created by Hermann Sprengel (1834–1906). Research conducted by Crookes and others ultimately led to the discovery of the electron in 1897 by J. J. Thomson (1856–1940). But the Crookes tube, as it came to be known, produced little light because the vacuum in it was too good and thus lacked the trace amounts of gas that are needed for electrically stimulated luminescence. Sir William Crookes, OM, FRS (17 June 1832 – 4 April 1919) was an English chemist and physicist. ... Hermann Sprengel (1834-1906) was a German chemist. ... For other uses, see Electron (disambiguation). ... Sir Joseph John “J.J.” Thomson, OM, FRS (18 December 1856 – 30 August 1940) was a British physicist and Nobel laureate, credited for the discovery of the electron and of isotopes, and the invention of the mass spectrometer. ... The Crookes tube is an evacuated glass cone with 3 node elements (one anode and two cathodes). ... Luminescence is light not generated by high temperatures alone. ...


Alexandre Edmond Becquerel observed in 1859 that certain substances gave off light when they were placed in a Geissler tube. He went on to apply thin coatings of luminescent materials to the surfaces of these tubes. Fluorescence occurred, but the tubes were very inefficient and had a short operating life. A few years earlier another scientist, George G. Stokes (1819–1903), had noted that ultraviolet light caused fluorspar to fluoresce, a property that would become critically important for the development of fluorescent lights many decades later. Alexandre-Edmond Becquerel Alexandre-Edmond Becquerel (March 24, 1820 - May 11, 1891) was a French physicist who studied the solar spectrum, magnetism, electricity, and optics. ... For other uses, see Ultraviolet (disambiguation). ... Fluorite (also called fluorspar) is a mineral composed of calcium fluoride, CaF2. ...


Early discharge lamps

While Becquerel was primarily interested in conducting scientific research into fluorescence, Thomas Edison (1847–1931) briefly pursued fluorescent lighting for its commercial potential. He invented a fluorescent lamp in 1896 which used a coating of calcium tungstate as the fluorescing substance, excited by X-rays, but although it received a patent in 1907[1], it was not put into production. As with a few other attempts to use Geissler tubes for illumination, it had a short operating life, and given the success of the incandescent light, Edison had little reason to pursue an alternative means of electrical illumination. Nikola Tesla made similar experiments in the 1890's, devising high frequency powered fluorescent bulbs that gave a bright greenish light, but as with Edison's devices, no commercial success was achieved. Edison redirects here. ... For other uses, see Calcium (disambiguation). ... An X-ray picture (radiograph), taken by Wilhelm Röntgen in 1896, of his wife, Anna Bertha Ludwigs[1] hand X-rays (or Röntgen rays) are a form of electromagnetic radiation with a wavelength in the range of 10 to 0. ... Nikola Tesla (Nih koh la TESS lah) [2](Serbian Cyrillic: ) (10 July 1856 – 7 January 1943) was an inventor, physicist, mechanical and electrical engineer. ...


Although Edison lost interest in fluorescent lighting, one of his former employees was able to create a gas-based lamp that achieved a measure of commercial success. In 1895 Daniel McFarlan Moore (1869–1933) demonstrated lamps 7 to 9 feet in length that used carbon dioxide or nitrogen to emit white or pink light, respectively. As with future fluorescent lamps, they were considerably more complicated than an incandescent bulb. Daniel McFarlan Moore (1869 - 1933) was a U.S. electrical engineer and inventor. ... Carbon dioxide (chemical formula: ) is a chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom. ... General Name, symbol, number nitrogen, N, 7 Chemical series nonmetals Group, period, block 15, 2, p Appearance colorless gas Standard atomic weight 14. ...


After years of work, Moore was able to extend the operating life of the lamps by inventing an electromagnetically controlled valve that maintained a constant gas pressure within the tube. Although Moore’s lamp was complicated, expensive to install, and required very high voltages, it was considerably more efficient than incandescent lamps, and it produced a more natural light than incandescents. From 1904 onwards Moore’s lighting system was installed in a number of stores and offices. Its success contributed to General Electric’s motivation to improve the incandescent lamp, especially its filament. GE’s efforts came to fruition with the invention of a tungsten-based filament. The extended lifespan of incandescent bulbs negated one of the key advantages of Moore’s lamp, but GE purchased the relevant patents in 1912. These patents and the inventive efforts that supported them were to be of considerable value when the firm took up fluorescent lighting more than two decades later. For other uses, see Tungsten (disambiguation). ...


At about the same time that Moore was developing his lighting system, another American was creating a means of illumination that also can be seen as a precursor to the modern fluorescent lamp. This was the mercury vapor lamp, invented by Peter Cooper Hewitt (1861–1921) and patented in 1901 (U.S. Pat. No. 889,692). Cooper-Hewitt’s lamp luminesced when an electric current was passed through mercury vapor at a low pressure. Unlike Moore’s lamps, those made by Cooper-Hewitt could be manufactured in standardized sizes and operated at low voltages. The mercury-vapor lamp was superior to the incandescent lamps of the time in terms of energy efficiency, but the blue-green light it produced limited its applications. It was, however, used for photography and some industrial processes. This article is about the element. ... This article is about the chemical use. ... Peter Cooper Hewitt (May 5, 1861 - August 25, 1921) was an American electrical engineer, who demonstrated the mercury-vapor lamp for which he deposited a patent. ... The article on electrical energy is located elsewhere. ... In the physical sciences, potential difference is the difference in potential between two points in a conservative vector field. ...


Mercury vapor lamps continued to be developed at a slow pace, especially in Europe, and by the early 1930s they received limited use for large-scale illumination. Some of them employed fluorescent coatings, but these were primarily used for color correction and not for enhanced light output. Mercury vapor lamps also anticipated the fluorescent lamp in their incorporation of a ballast to maintain a constant current.


Cooper-Hewitt had not been the first to use mercury vapor for illumination, as earlier efforts had been mounted by Way, Rapieff, Arons, and Bastian and Salisbury. Of particular importance was the mercury vapor lamp invented by Küch in Germany. This lamp used quartz in place of glass to allow higher operating temperatures, and hence greater efficiency. Although its light output relative to electrical consumption was better than other sources of light, the light it produced was similar to that of the Cooper-Hewitt lamp in that it lacked the red portion of the spectrum, making it unsuitable for ordinary lighting.


Neon lamps

The next step in gas-based lighting took advantage of the luminescent qualities of neon, an inert gas that had been discovered in 1898. In 1909 Georges Claude (1870–1960), a French chemist, observed the red glow that was produced when running an electric current through a neon-filled tube. He also discovered that argon emitted a blue glow. While neon lighting was used around 1930 in France for general illumination, it was no more energy-efficient than conventional incandescent lighting. Neon lighting came to be used primarily for eye-catching signs and advertisements. Neon lighting was not irrelevant to the development of fluorescent lighting, however, as Claude’s improved electrode (patented in 1915) overcame “sputtering”, a major source of electrode degradation. Sputtering occurred when ionized particles struck an electrode and tore off bits of metal. Although Claude’s invention required electrodes with a lot of surface area, it showed that a major impediment to gas-based lighting could be overcome. For other uses, see Neon (disambiguation). ... Inspired in part by Daniel McFarlan Moores invention, Moore’s Lamp, Paris born chemist and inventor, Georges Claude invented the neon light by passing an electric current through inert gases made them light very brightly. ... General Name, symbol, number argon, Ar, 18 Chemical series noble gases Group, period, block 18, 3, p Appearance colorless Standard atomic weight 39. ... Alternative meanings: There is also an Electric-type Pokémon named Electrode. ...


The development of the neon light also was significant for the last key element of the fluorescent lamp, its fluorescent coating. In 1926 Jacques Risler received a French patent for the application of fluorescent coatings to neon light tubes. The main use of these lamps, which can be considered the first commercially successful fluorescents, was for advertising, not general illumination. This, however, was not the first use of fluorescent coatings. As has been noted above, Edison used calcium tungstate for his unsuccessful lamp. Other efforts had been mounted, but all were plagued by low efficiency and various technical problems. Of particular importance was the invention in 1927 of a low-voltage “metal vapor lamp” by Friedrich Meyer, Hans-Joachim Spanner, and Edmund Germer, who were employees of a German firm in Berlin. A German patent was granted but the lamp never went into commercial production. Edmund Germer (August 24, 1901 - August 10, 1987) was a German inventor granted as the father of the fluorescent lamp for which he deposited U.S. Patent No 2,182,732 in 1926 with Friedrich Meyer and Hans J. Spanner. ... This article is about the capital of Germany. ...


Commercialization of fluorescent lamps

All the major features of fluorescent lighting were in place at the end of the 1920s. Decades of invention and development had provided the key components of fluorescent lamps: economically manufactured glass tubing, inert gases for filling the tubes, electrical ballasts, long-lasting electrodes, mercury vapor as a source of luminescence, effective means of producing a reliable electrical discharge, and fluorescent coatings that could be energized by ultraviolet light. At this point, intensive development was more important than basic research.


In 1934, Arthur Compton, a renowned physicist and GE consultant, reported to the GE lamp department on successful experiments with fluorescent lighting at General Electric Co., Ltd. in Great Britain (unrelated to General Electric in the United States). Stimulated by this report, and with all of the key elements available, a team led by George E. Inman built a prototype fluorescent lamp in 1934 at General Electric’s Nela Park (Ohio) engineering laboratory. This was not a trivial exercise; as noted by Arthur A. Bright, “A great deal of experimentation had to be done on lamp sizes and shapes, cathode construction, gas pressures of both argon and mercury vapor, colors of fluorescent powders, methods of attaching them to the inside of the tube, and other details of the lamp and its auxiliaries before the new device was ready for the public.” Arthur Holly Compton (September 10, 1892 – March 15, 1962) won the Nobel Prize in Physics (1927) for discovery of the Compton effect named in his honor. ... Nela Park, Building 307 Nela Park is the traditional headquarters of GE Lighting, and is located in East Cleveland, Ohio. ...


In addition to having engineers and technicians along with facilities for R&D work on fluorescents, General Electric controlled what it regarded as the key patents covering fluorescent lighting, including the patents originally issued to Cooper-Hewitt, Moore, and Küch. More important than these was a patent covering an electrode that did not disintegrate at the gas pressures that ultimately were employed in fluorescent lamps. This invention had been created by Albert W. Hull of GE’s Schenectady Research Laboratory, and was registered as U.S. Pat. No. 1,790,153. For other uses, see Electrode (disambiguation). ...


While the Hull patent gave GE a basis for claiming legal rights over the fluorescent lamp, a few months after the lamp went into production the firm learned of a U.S. patent application had been filed in 1927 for the aforementioned "metal vapor lamp" invented in Germany by Meyer, Spanner, and Germer. The patent application indicated that the lamp had been created as a superior means of producing ultraviolet light, but the application also contained a few statements referring to fluorescent illumination. Efforts to obtain a U.S. patent had met with numerous delays, but were it to be granted, the patent might have caused serious difficulties for GE. At first, GE sought to block the issuance of a patent by claiming that priority should go to one of their employees, Leroy J. Buttolph, who according to their claim had invented a fluorescent lamp in 1919 and whose patent application was still pending. GE also had filed a patent application in 1936 in Inman’s name to cover the “improvements” wrought by his group. In 1939 GE decided that the claim of Meyer, Spanner, and Germer had some merit, and that in any event a long interference procedure was not in their best interest. They therefore dropped the Buttolph claim and paid $180,000 to acquire the Meyer, et al. application, which at that point was owned by a firm known as Electrons, Inc. The patent (U.S. Pat. No. 2,182,732) was duly awarded in December 1939. This patent, along with the Hull patent, put GE on what seemed to be firm legal ground, although it faced years of legal challenges from Sylvania Electric Products, Inc., which claimed infringement on patents that it held. This article is about law in society. ... Sylvania literally means forest land in Latin. ... In a legal context, an infringement refers to the violation of a law or a right. ...


Even though the patent issue would not be completely resolved for many years, General Electric’s strength in manufacturing and marketing gave it a pre-eminent position in the emerging fluorescent light market. Sales of "fluorescent lumiline lamps" commenced in 1938 when four different sizes of tubes were put on the market. During the following year GE and Westinghouse publicized the new lights through exhibitions at the New York World’s Fair and the Golden Gate Exposition in San Francisco. Fluorescent lighting systems spread rapidly during World War II as wartime manufacturing intensified lighting demand. By 1951 more light was produced in the United States by fluorescent lamps than by incandescent lamps. The Westinghouse Electric Corporation was an organization founded by George Westinghouse in 1886 as Westinghouse Electric & Manufacturing Company. ... There have been two Worlds fairs in New York City: 1939 New York Worlds Fair (1939-1940) at Flushing Meadows in Queens gave us Futurama, the Trylon, and Perisphere. ...


Principles of operation

The fundamental means for conversion of electrical energy into radiant energy in a fluorescent lamp relies on inelastic scattering of electrons. An incident electron collides with an atom in the gas. If the free electron has enough kinetic energy, it transfers energy to the atom's outer electron, causing that electron to temporarily jump up to a higher energy level. This is why the collision is called 'inelastic,' as some of the energy is transferred. In particle physics, inelastic scattering is a fundamental scattering process in which the momentum of an incident particle is not conserved. ... The cars of a roller coaster reach their maximum kinetic energy when at the bottom of their path. ... A quantum mechanical system can only be in certain states, so that only certain energy levels are possible. ...


This higher energy state is unstable, and the atom will emit an ultraviolet photon as the atom's electron reverts to a lower, more stable, energy level. Most of the photons that are released from the mercury atoms have wavelengths in the ultraviolet part of the spectrum. This is not visible to the human eye, so must be converted into visible light. This is done by making use of fluorescence. Ultraviolet photons are absorbed by electrons in the atoms of the lamp's fluorescent coating, causing a similar energy jump, then drop, with emission of a further photon. The photon that is emitted from this second interaction has a lower energy than the one that caused it. The chemicals that make up the phosphor are chosen so that these emitted photons are at wavelengths visible to the human eye. The difference in energy between the absorbed ultra-violet photon and the emitted visible light photon goes to heat up the phosphor coating. In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ... For other uses, see Wavelength (disambiguation). ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ...


Construction

Close-up of the cathodes and anodes of a germicidal lamp (an essentially-similar design that uses no fluorescent phosphor (known chemically as a fluorophor), allowing the electrodes to be seen.)
Close-up of the cathodes and anodes of a germicidal lamp (an essentially-similar design that uses no fluorescent phosphor (known chemically as a fluorophor), allowing the electrodes to be seen.)
The unfiltered ultraviolet glow of a germicidal lamp is produced by a low pressure mercury vapor discharge (identical to that in a fluorescent lamp) in an uncoated fused quartz envelope.
The unfiltered ultraviolet glow of a germicidal lamp is produced by a low pressure mercury vapor discharge (identical to that in a fluorescent lamp) in an uncoated fused quartz envelope.

A fluorescent lamp tube is filled with a gas containing low pressure mercury vapor and argon, xenon,neon, or krypton. The pressure inside the lamp is around 0.3% of atmospheric pressure. The inner surface of the bulb is coated with a fluorescent (and often slightly phosphorescent) coating made of varying blends of metallic and rare-earth phosphor salts. The bulb's cathode is typically made of coiled tungsten which is coated with a mixture of barium, strontium and calcium oxides (chosen to have a relatively low thermionic emission temperature). When the light is turned on, the electric power heats up the cathode enough for it to emit electrons. These electrons collide with and ionize noble gas atoms in the bulb surrounding the filament to form a plasma by a process of impact ionization. Image File history File links Download high-resolution version (870x1134, 78 KB) Summary Close-up of the electrodes and warning text on a 9W germicidal lamp in a compact-fluorescent form factor. ... Image File history File links Download high-resolution version (870x1134, 78 KB) Summary Close-up of the electrodes and warning text on a 9W germicidal lamp in a compact-fluorescent form factor. ... A 9W germicidal lamp in a modern compact fluorescent lamp form factor Close-up of the electrodes and the safety warning An EPROM. The small quartz window admits UV light during erasure. ... Image File history File links Download high-resolution version (538x1324, 87 KB) Glow of a germicidal lamp as excited by a high voltage probe (handheld tesla coil). ... Image File history File links Download high-resolution version (538x1324, 87 KB) Glow of a germicidal lamp as excited by a high voltage probe (handheld tesla coil). ... A 9W germicidal lamp in a modern compact fluorescent lamp form factor Close-up of the electrodes and the safety warning An EPROM. The small quartz window admits UV light during erasure. ... For other uses, see Gas (disambiguation). ... General Name, symbol, number argon, Ar, 18 Chemical series noble gases Group, period, block 18, 3, p Appearance colorless Standard atomic weight 39. ... General Name, Symbol, Number xenon, Xe, 54 Chemical series noble gases Group, Period, Block 18, 5, p Appearance colorless Standard atomic weight 131. ... For other uses, see Neon (disambiguation). ... For other uses, see Krypton (disambiguation). ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized cadmium selenide (CdSe) quantum dots. ... In common use, phosphorescence also refers to the emission of light by bioluminescent plankton, and some other forms of chemoluminescence. ... This article is about metallic materials. ... Strictly speaking, a rare earth is an oxide of a rare earth element. ... Green screen A phosphor is a substance that exhibits the phenomenon of phosphorescence (sustained glowing after exposure to light or energised particles such as electrons). ... This article is about common table salt. ... For other uses, see Tungsten (disambiguation). ... Closeup of the filament on a low pressure mercury gas discharge lamp showing white thermionic emission mix coating on the central portion of the coil. ... This article is about the chemical series. ... For other uses, see Plasma. ... Impact ionization is the process in a material by which one energetic charge carrier can lose energy by the creation of other charge carriers. ...


As a result of avalanche ionization, the conductivity of the ionized gas rapidly rises, allowing higher currents to flow through the lamp. The mercury is then likewise ionized, causing it to emit light in the ultraviolet (UV) region of the spectrum predominantly at wavelengths of 253.7 nm and 185 nm. An electron avalanche is a process in which a number of free electrons in a medium (usually a gas) are subjected to a strong electric field accelerate, ionizing the mediums atoms by collision (creating positive ions), forming new electrons to undergo the same process in successive cycles. ... For other uses, see Ultraviolet (disambiguation). ... For other uses, see Wavelength (disambiguation). ... A nanometre (American spelling: nanometer) is 1. ...


The efficiency of fluorescent lighting owes much to the fact that low pressure mercury discharges emit about 65% of their total light at the 254 nm line (also about 10-20% of the light emitted in UV is at the 185 nm line). The UV light is absorbed by the bulb's fluorescent coating, which re-radiates the energy at longer wavelengths to emit visible light. The blend of phosphors controls the color of the light, and along with the bulb's glass prevents the harmful UV light from escaping. In physics, absorption is the process by which the energy of a photon is taken up by another entity, for example, by an atom whose valence electrons make transition between two electronic energy levels. ... Electromagnetic radiation or EM radiation is a combination (cross product) of oscillating electric and magnetic fields perpendicular to each other, moving through space as a wave, effectively transporting energy and momentum. ... The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. ... Color is an important part of the visual arts. ... This article is about the material. ...


Electrical aspects of operation

Fluorescent lamps are negative differential resistance devices, so as more current flows through them, the electrical resistance of the fluorescent lamp drops, allowing even more current to flow. Connected directly to a constant-voltage mains power line, a fluorescent lamp would rapidly self-destruct due to the uncontrolled current flow. To prevent this, fluorescent lamps must use an auxiliary device, a ballast, to regulate the current flow through the tube; and to provide a higher voltage for starting the lamp. A VI curve with a negative differential resistance region Negative resistance or negative differential resistance (NDR) is a property of electrical circuit elements composed of certain materials in which, over certain voltage ranges, current is a decreasing function of voltage. ... International safety symbol Caution, risk of electric shock (ISO 3864), colloquially known as high voltage symbol. ... An automotive (ignition system) ballast resistor An electrical ballast (sometimes called control gear) is a device intended to limit the amount of current flowing in an electric circuit. ...


While the ballast could be (and occasionally is) as simple as a resistor, substantial power is wasted in a resistive ballast so ballasts usually use an inductor instead. For operation from AC mains voltage, the use of simple magnetic ballast is common. In countries that use 120 V AC mains, the mains voltage is insufficient to light large fluorescent lamps so the ballast for these larger fluorescent lamps is often a step-up autotransformer with substantial leakage inductance (so as to limit the current flow). Either form of inductive ballast may also include a capacitor for power factor correction. Resistor symbols (American) Resistor symbols (Europe, IEC) Axial-lead resistors on tape. ... An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ... Josephson junction array chip developed by NIST as a standard volt. ... City lights viewed in a motion blurred exposure. ... For other uses, see Transformer (disambiguation). ... Leakage inductance is that property of an electrical transformer that causes a winding to appear to have some pure inductance in series with the mutually-coupled transformer windings. ... See Capacitor (component) for a discussion of specific types. ... Power factor correction (PFC) is a technique of counteracting the undesirable effects of electric loads that create a power factor (p. ...


Many different circuits have been used to start and run fluorescent lamps. The choice of circuit is based on factors such as mains voltage, tube length, initial cost, long term cost, instant versus non-instant starting, temperature ranges and parts availability, etc. The names of these different circuits vary by country and this can cause confusion. For example, pre-heat in this context has valid but different meanings in the US and elsewhere.


Fluorescent lamps can run directly from a DC supply of sufficient voltage to strike an arc. The ballast must be resistive, and would consume about as much power as the lamp. When operated from DC, the polarity of the supply to the lamp must be reversed every time the lamp is started; otherwise, the mercury accumulates at one end of the tube. Currently, fluorescent lamps are almost never operated directly from DC; instead, an inverter converts the DC into AC and provides the current-limiting function as described below for electronic ballasts. Direct current (DC or continuous current) is the continuous flow of electricity through a conductor such as a wire from high to low potential. ... An inverter may be: inverter (electrical), which converts direct current (DC) to alternating current (AC) inverter (logic gate), also called a NOT gate. ...


For line operation, ballasts may employ transistors or other semiconductor components to convert mains voltage into high-frequency AC while also regulating the current flow in the lamp. These are referred to as "electronic ballasts", and take advantage of the higher efficacy of lamps operated with higher-frequency current. Assorted discrete transistors A transistor is a semiconductor device, commonly used as an amplifier or an electrically controlled switch. ... A semiconductor is a solid material that has electrical conductivity in between that of a conductor and that of an insulator; it can vary over that wide range either permanently or dynamically. ... For other uses, see Frequency (disambiguation). ... City lights viewed in a motion blurred exposure. ... Surface mount electronic components Electronics is the study of the flow of charge through various materials and devices such as semiconductors, resistors, inductors, capacitors, nano-structures and vacuum tubes. ...


Flicker

Fluorescent lamps operated on AC will flicker at twice the mains frequency, since the power being delivered to the lamp drops to zero twice per cycle (120 Hz or 100 Hz). If the lamp has a magnetic ballast, this may also emit a humming sound. Magnetic ballasts are usually filled with a tarry potting compound to reduce emitted noise. Both the hum and flicker are eliminated in lamps which use a high-frequency electronic ballast, such as the increasingly popular compact fluorescent lamp. Low-energy light-bulb redirects here. ...


In some circumstances, fluorescent lamps operated at mains frequency can also produce flicker at the mains frequency (50 or 60 Hz) itself, which is noticeable by more people. This can happen in the last few hours of tube life when the cathode emission coating at one end is almost run out, and that cathode starts having difficulty emitting enough electrons into the gas fill, resulting in slight rectification and hence uneven light output in positive and negative going mains cycles. Mains frequency flicker can also sometimes be emitted from the very ends of the tubes, as a result of each tube electrode alternately operating as an anode and cathode each half mains cycle, and producing slightly different light output pattern in anode or cathode mode. Flicker at mains frequency is more noticeable in the peripheral vision than it is in the center of gaze. Diagram of a copper cathode in a Daniells cell. ... For other uses, see Electron (disambiguation). ... A rectifier is an electrical device that converts alternating current to rectified direct current, a process known as rectification. ... Diagram of a zinc anode in a galvanic cell. ... Diagram of a copper cathode in a Daniells cell. ... Peripheral vision is a part of vision that occurs outside the very center of gaze. ...


New fluorescent lamps may show a twisting spiral pattern of light in a part of the lamp. This effect is due to loose cathode material and usually disappears after a few hours of operation. [2]


Efficacy

The efficacy of fluorescent tubes ranges from about 16 lumens/watt for a 4 watt tube with an ordinary ballast to as high as about 100 lumens/watt for a 32 watt tube with modern electronic ballast, commonly averaging 50 to 67 lm/W overall. Most compact fluorescents 13 watts or more with integral electronic ballasts achieve about 60 lumens/watt. Due to phosphor degradation as they age, the average brightness over the entire service life is actually about 10% less. Lamps are rated by lumens after 100 hours of operation. [3] For a given fluorescent tube, a high-frequency electronic ballast gives about 10% efficacy improvement over an inductive ballast. Efficacy is the ability to produce a desired amount of a desired effect. ...


Starting

A preheat fluorescent lamp circuit using an automatic starting switch.)A: Fluorescent Tube, B: Power (+220 Volts), C: Starter, D: Switch (Bi-metallic thermostat), E: Capacitor, F: Filaments, G: Ballast)
230V ballast for 18-20W
230V ballast for 18-20W
A preheat fluorescent lamp "starter" (automatic starting switch)
A preheat fluorescent lamp "starter" (automatic starting switch)

The mercury atoms in the fluorescent tube must be ionized before the arc can "strike" within the tube. For small lamps, it does not take much voltage to strike the arc and starting the lamp presents no problem, but larger tubes require a substantial voltage (in the range of a thousand volts). Image File history File links Starterp. ... Image File history File links Starterp. ...


In some cases, that is exactly how it is done: instant start fluorescent tubes simply use a high enough voltage to break down the gas and mercury column and thereby start arc conduction. These tubes can be identified by

  1. a single pin at each end of the tube, and
  2. the lampholders that they fit into having a "disconnect" socket at the low-voltage end to ensure that the mains current is automatically removed so that a person replacing the lamp cannot receive a high-voltage electric shock.

In other cases, a separate starting aid must be provided. Some fluorescent designs (preheat lamps) use a combination filament/cathode at each end of the lamp in conjunction with a mechanical or automatic switch (see photo) that initially connect the filaments in series with the ballast and thereby preheat the filaments prior to striking the arc. This is the oldest type of fluorescent lamp. Sign warning of possible electric shock hazard An electric shock can occur upon contact of a humans body with any source of voltage high enough to cause sufficient current flow through the muscles or hair. ... An electrical filament is a thread of metal, usually tungsten, which is used to convert electricity into light in incandescent light bulbs (as developed in 1878 by Joseph Wilson Swan, among others), and into heat in vacuum tube devices. ... Diagram of a copper cathode in a Daniells cell. ...


These systems are standard equipment in 240 V countries (and for 120 V lamps up to about 30 watts), and generally use a glow starter. Before the 1960s, four-pin thermal starters and manual switches were also used. Electronic starters are also sometimes used with these electromagnetic ballast fittings.


The automatic glow starter shown in the photograph consists of a small gas-discharge tube, containing neon and/or argon and fitted with a bi-metallic electrode. The special bi-metallic electrode is the key to the automatic starting mechanism. A bi-metallic strip is used to convert a temperature change into mechanical displacement. ...


When starting the lamp, a glow discharge will appear over the electrodes of the starter. This glow discharge will heat the gas and cause the bi-metallic electrode to bend towards the other electrode. When the electrodes touch, the two filaments of the fluorescent lamp and the ballast will effectively be switched in series to the supply voltage. This causes the filaments to glow and emit electrons into the gas column by thermionic emission. In the starter's tube, the touching electrodes have stopped the glow discharge, causing the gas to cool down again. The bi-metallic electrode also cools down and starts to move back. When the electrodes separate, the inductive kick from the ballast provides the high voltage to start the lamp. The starter additionally has a capacitor wired in parallel to its gas-discharge tube, in order to prolong the electrode life. Closeup of the filament on a low pressure mercury gas discharge lamp showing white thermionic emission mix coating on the central portion of the coil. ... A snubber is a simple electrical circuit used to suppress (snub) band to band electrical transients. ... See Capacitor (component) for a discussion of specific types. ...


Tube strike is reliable in these systems, but glow starters will often cycle a few times before letting the tube stay lit, which causes objectionable flashing during starting. The older thermal starters behaved better in this respect. Once the tube is struck, the impinging main discharge then keeps the filament/cathode hot, permitting continued emission.


If the tube fails to strike, or strikes but then extinguishes, the starting sequence is repeated. With automated starters such as glowstarters, a failing tube will thus cycle endlessly, flashing as the starter repeatedly starts the worn-out lamp, and the lamp then quickly goes out as emission is insufficient to keep the cathodes hot, and lamp current is too low to keep the glowstarter open. This causes flickering, and runs the ballast at above design temperature.


Some more advanced starters time out in this situation, and do not attempt repeated starts until power is reset. Some older systems used a thermal overcurrent trip to detect repeated starting attempts. These require manual reset.


Newer rapid start ballast designs provide filament power windings within the ballast; these rapidly and continuously warm the filaments/cathodes using low-voltage AC. No inductive voltage spike is produced for starting, so the lamps must usually be mounted near a grounded (earthed) reflector to allow the glow discharge to propagate through the tube and initiate the arc discharge.


Electronic ballasts often revert to a style in-between the preheat and rapid-start styles: a capacitor (or sometimes an autodisconnecting circuit) may complete the circuit between the two filaments, providing filament preheating. When the tube lights, the voltage and frequency across the tube and capacitor typically both drop, thus capacitor current falls to a low but non-zero value. Generally this capacitor and the inductor, which provides current limiting in normal operation, form a resonant circuit, increasing the voltage across the lamp so it can easily start. This article is about resonance in physics. ...


Some electronic ballasts use programmed start. The output AC frequency is started above the resonance frequency of the output circuit of the ballast; and after the filaments are heated, the frequency is rapidly decreased. If the frequency approaches the resonant frequency of the ballast, the output voltage will increase so much that the lamp will ignite. If the lamp does not ignite, an electronic circuit stops the operation of the ballast. For other uses, see Frequency (disambiguation). ... This article is about resonance in physics. ...


Beginning in the 1990s a new type of ballast came into the mainstream, with a more expensive but significantly more efficient design: high frequency operation. These newer design high frequency ballasts have been used with either rapid start or pre-heat cathode/anode style lamps (with pins shorted at the lamp end), and use high frequency to excite the mercury within the lamp. These newer electronic ballasts convert the 50 or 60 Hertz coming into the ballast to an output frequency in excess of 100 kHz. This allows for a more efficient system that generates less waste heat and requires significantly less power to light the lamp, and operates in a rapid starting manner. These are used in several applications, including new generation tanning lamp systems, whereby a 100 watt lamp (i.e., F71T12BP) can be lighted using 65 to 70 watts of actual power while obtaining the same lumens as traditional ballasts at full power. These operate with voltages that can be almost 600 volts, requiring some consideration in housing design, and can cause a minor limitation in the length of the wire leads from the ballast to the lamp ends. These ballasts run just a few degrees above ambient temperature, which is partly why they are more efficient and allows them to be used in applications that would be inappropriate for hotter running electronics. Typical tanning lamp with F71T12 markings. ...


End of life

The end of life failure mode for fluorescent lamps varies depending how they are used and their control gear type. There are three main failure modes currently, and a fourth which is starting to appear:


Emission mix

Closeup of the filament on a low pressure mercury gas discharge lamp showing white thermionic emission mix coating on the central portion of the coil. Typically made of a mixture of barium, strontium and calcium oxides, the coating is sputtered away through normal use, often eventually resulting in lamp failure.

The "emission mix" on the tube filaments/cathodes is necessary to enable electrons to pass into the gas via thermionic emission at the tube operating voltages used. The mix is slowly sputtered off by bombardment with electrons and mercury ions during operation, but a larger amount is sputtered off each time the tube is started with cold cathodes. (The method of starting the lamp and hence the control gear type has a significant impact on this.) Lamps operated for typically less than 3 hours each switch-on will normally run out of the emission mix before other parts of the lamp fail. The sputtered emission mix forms the dark marks at the tube ends seen in old tubes. When all the emission mix is gone, the cathode cannot pass sufficient electrons into the gas fill to maintain the discharge at the designed tube operating voltage. Ideally, the control gear should shut down the tube when this happens. However, some control gear will provide sufficient increased voltage to continue operating the tube in cold cathode mode, which will cause overheating of the tube end and rapid disintegration of the electrodes and their support wires until they are completely gone or the glass cracks, wrecking the low pressure gas fill and stopping the gas discharge. Image File history File links Download high-resolution version (813x758, 148 KB) Closeup of a filament in a germicidal lamp showing thermionic coating. ... Image File history File links Download high-resolution version (813x758, 148 KB) Closeup of a filament in a germicidal lamp showing thermionic coating. ... For other uses, see Barium (disambiguation). ... General Name, Symbol, Number strontium, Sr, 38 Chemical series alkaline earth metals Group, Period, Block 2, 5, s Appearance silvery white metallic Standard atomic weight 87. ... For other uses, see Calcium (disambiguation). ... Closeup of the filament on a low pressure mercury gas discharge lamp showing white thermionic emission mix coating on the central portion of the coil. ... Sputtering is a physical process whereby atoms in a solid target material are ejected into the gas phase due to bombardment of the material by energetic ions. ... This article is about light sources and indicators. ...


Ballast electronics

This is only relevant to compact fluorescent lamps with integral electrical ballasts. Ballast electronics failure is a somewhat random process which follows the standard failure profile for any electronic devices. Integral electronic ballasts suffer from shortened lifespans in high humidity applications. There is an initial small peak of early failures, followed by a drop and steady increase over lamp life. Life of electronics is heavily dependent on operating temperature—it typically halves for each 10 °C temperature rise. The quoted average life of a lamp is usually at 25 °C ambient (this may vary by country). The average life of the electronics at this temperature is normally greater than this, so at this temperature, not many lamps will fail due to failure of the electronics. In some fittings, the ambient temperature could be well above this, in which case failure of the electronics may become the predominant failure mechanism. Similarly, running a compact fluorescent lamp base-up will result in hotter electronics and shorter average life (particularly with higher power rated ones). Electronic ballasts should be designed to shut down the tube when the emission mix runs out as described above. In the case of integral electronic ballasts, since they never have to work again, this is sometimes done by having them deliberately burn out some component to permanently cease operation. Low-energy light-bulb redirects here. ... An automotive (ignition system) ballast resistor An electrical ballast (sometimes called control gear) is a device intended to limit the amount of current flowing in an electric circuit. ...


Phosphor

The phosphor drops off in efficiency during use. By around 25,000 operating hours, it will typically be half the brightness of a new lamp (although some manufacturers claim much longer half-lives for their lamps). Lamps which do not suffer failures of the emission mix or integral ballast electronics will eventually develop this failure mode. They still work, but have become dim and inefficient. The process is slow, and often only becomes obvious when a new lamp is operating next to an old lamp.


Loss of mercury

Mercury is slowly absorbed into glass, phosphor, and tube electrodes throughout the lamp life, where it can no longer function. Newer lamps now have just enough mercury to last the expected life of the lamp. Loss of mercury will take over from failure of the phosphor in some lamps. The failure symptoms are similar, except loss of mercury initially causes an extended run-up time to full light output, and finally causes the lamp to glow a dim pink when the mercury runs out and the argon base gas takes over as the primary discharge.


Phosphors and the spectrum of emitted light

Some people find the color rendition produced by some fluorescent lamps to be harsh and displeasing. A healthy person can sometimes appear to have an unhealthy skin tone under fluorescent lighting. The extent to which this phenomenon occurs is related to the light's spectral composition, and may be gauged by its Color Rendering Index (CRI). Colour rendering index, or CRI, is a measure of the quality of colour light, devised by the International Commission on Illumination (CIE). ...


CRI is a measure of how well balanced the different color components of the white light are, relative to daylight or a blackbody. By definition, an incandescent lamp has a CRI of 100. Real-life fluorescent tubes achieve CRIs of anywhere from 50% to 99%. Fluorescent lamps with low CRI have phosphors which emit too little red light. Skin appears less pink, and hence "unhealthy" compared with incandescent lighting. Colored objects appear muted. For example, a low CRI 6800K halophosphate tube (an extreme example)will make reds appear dull red or even brown.


Correlated color temperature (CCT) is a measure of the "shade" of whiteness of a light source, again by comparison with a blackbody. Typical incandescent lighting is 2700K which is yellowish-white. Halogen lighting is 3000K. Fluorescent lamps are manufactured to a chosen CCT by altering the mixture of phosphors inside the tube. Warm-white fluorescents have CCT of 2700K and are popular for residential lighting. Neutral-white fluorescents have a CCT of 3000K or 3500K. Cool-white fluorescents have a CCT of 4100K and are popular for office lighting. Daylight fluorescents have a CCT of 5000K to 6500K, which is bluish-white. White light is commonly described by its color temperature. ...


High CCT lighting generally requires higher light levels. At dimmer illumination levels, the human eye perceives lower color temperatures as more natural, as related through the Kruithof curve. So, a dim 2700K incandescent lamp appears natural, and a bright 5000K lamp also appears natural, but a dim 5000K fluorescent lamp appears too pale. Daylight-type fluorescents look natural only if they are very bright. In color vision, the color experience of a given light mixture may vary with absolute luminosity, due to the fact that both rods and cones are active at once in the eye, with each having different color curves, and rods taking over gradually from cones as the brightness of the...


Some of the least pleasant light comes from tubes containing the older halophosphate type phosphors (chemical formula Ca5(PO4)3(F,Cl):Sb3+,Mn2+). The bad color reproduction is due to the fact that this phosphor mainly emits yellow and blue light, and relatively little green and red. In the absence a reference, this mixture appears white to the eye, but the light has an incomplete spectrum. The CRI of such lamps is around 60. Green screen A phosphor is a substance that exhibits the phenomenon of phosphorescence (sustained glowing after exposure to light or energised particles such as electrons). ... For other uses, see Calcium (disambiguation). ... General Name, symbol, number phosphorus, P, 15 Chemical series nonmetals Group, period, block 15, 3, p Appearance waxy white/ red/ black/ colorless Standard atomic weight 30. ... This article is about the chemical element and its most stable form, or dioxygen. ... Distinguished from fluorene and fluorone. ... General Name, symbol, number chlorine, Cl, 17 Chemical series nonmetals Group, period, block 17, 3, p Appearance yellowish green Standard atomic weight 35. ... This article is about the element. ... General Name, symbol, number manganese, Mn, 25 Chemical series transition metals Group, period, block 7, 4, d Appearance silvery metallic Standard atomic weight 54. ... This article deals with the general meaning of spectrum and the history of its use. ...


Since the 1990s, higher quality fluorescent lamps use either a higher CRI halophosphate coating, or a triphosphor mixture, based on europium and terbium ions, that have emission bands more evenly distributed over the spectrum of visible light. High CRI halophosphate and triphosphor tubes give a more natural color reproduction to the human eye. The CRI of such lamps is typically 82-100. General Name, Symbol, Number europium, Eu, 63 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 151. ... General Name, Symbol, Number terbium, Tb, 65 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 158. ...

Fluorescent lamp spectra
Typical fluorescent lamp with "rare earth" phosphor A typical "cool white" fluorescent lamp utilizing two rare earth doped phosphors, Tb3+, Ce3+:LaPO4 for green and blue emission and Eu:Y2O3 for red. For an explanation of the origin of the individual peaks click on the image. Note that several of the spectral peaks are directly generated from the mercury arc. This is likely the most common type of fluorescent lamp in use today.
An older style halophosphate phosphor fluorescent lamp Halophosphate phosphors in these lamps usually consist of trivalent antimony and divalent manganese doped calcium halophosphate (Ca5(PO4)3(Cl,F):Sb3+, Mn2+). The color of the light output can be adjusted by altering the ratio of the blue emitting antimony dopant and orange emitting manganese dopant. The color rendering ability of these older style lamps is quite poor. Halophosphate phosphors were invented by A.H. McKeag et al in 1942.
"Natural sunshine" fluorescent light An explanation of the origin of the peaks is on the image page.
Yellow fluorescent lights The spectrum is nearly identical to a normal fluorescent bulb except for a near total lack of light below 500 nanometers. This effect can be achieved through either specialized phosphor use or more commonly by the use of a simple yellow light filter. These lamps are commonly used as lighting for photolithography work in cleanrooms and as "bug repellant" outdoor lighting (the efficacy of which is questionable).
Spectrum of a "blacklight" bulb There is typically only one phosphor present in a blacklight bulb, usually consisting of europium-doped strontium fluoroborate which is contained in an envelope of Wood's glass.

Rare earth ore Rare earth elements and rare earth metals are trivial names sometimes applied to a collection of 17 chemical elements in the periodic table, namely scandium, yttrium, and the lanthanides. ... Image File history File links Download high resolution version (1268x777, 18 KB)Spectrum with peaks labelled taken with an Ocean Optics spectrometer [1] of ambient light provided by fluorecent lamps. ... General Name, Symbol, Number lanthanum, La, 57 Chemical series lanthanides Group, Period, Block 3, 6, f Appearance silvery white Atomic mass 138. ... Image File history File links Download high-resolution version (3900x2628, 361 KB)Spectrum of an old style (halophosphate phosphor) fluorescent light. ... This article is about the element. ... General Name, symbol, number manganese, Mn, 25 Chemical series transition metals Group, period, block 7, 4, d Appearance silvery metallic Standard atomic weight 54. ... For other uses, see Calcium (disambiguation). ... General Name, symbol, number chlorine, Cl, 17 Chemical series nonmetals Group, period, block 17, 3, p Appearance yellowish green Standard atomic weight 35. ... Distinguished from fluorene and fluorone. ... Image File history File links Download high-resolution version (3415x2368, 157 KB)[edit] Summary Spectrum of yellow fluorescent lights in a cleanroom. ... Photolithography is a process used in semiconductor device fabrication to transfer a pattern from a photomask (also called reticle) to the surface of a substrate. ... NASAs Glenn Research Center cleanroom. ... BlackLight Is a Rock Band set up April 2006. ... Image File history File links Download high resolution version (1284x827, 18 KB) Summary Spectrum of light from a fluorescent black light with peaks labelled. ... General Name, Symbol, Number europium, Eu, 63 Chemical series lanthanides Group, Period, Block n/a, 6, f Appearance silvery white Atomic mass 151. ... General Name, Symbol, Number strontium, Sr, 38 Chemical series alkaline earth metals Group, Period, Block 2, 5, s Appearance silvery white metallic Standard atomic weight 87. ... Borates in chemistry are chemical compounds containing boron bonded to three oxygen atoms written as B(OR)3. ... A black light bulb. ...

Usage

Fluorescent light bulbs come in many shapes and sizes. The compact fluorescent light bulb (CF) is becoming more popular. Many compact fluorescent lamps integrate the auxiliary electronics into the base of the lamp, allowing them to fit into a regular light bulb socket. Compact fluorescent light bulb A compact fluorescent light bulb (CFL bulb) is a type of fluorescent lamp which screws into a regular light bulb socket, or plugs into a small lighting fixture. ...


In the US, residential use of fluorescent lighting remains low (generally limited to kitchens, basements, hallways and other areas), but schools and businesses find the cost savings of fluorescents to be significant and rarely use incandescent lights. A residential area is a type of land use where the predominant use is residential. ... A kitchen is a room used for food preparation and sometimes entertainment. ... A townhouse with basement windows showing A basement is one or more floors of a building that are either completely or partially below the ground floor. ... For other uses, see Hall (disambiguation). ... Students in Rome, Italy. ... In economics, a business (also called firm or enterprise) is a legally recognized organizational entity designed to provide goods and/or services to consumers or corporate entities such as governments, charities or other businesses. ...


Lighting arrangements use fluorescent tubes in an assortment of tints of white. Sometimes this is because of the lack of appreciation for the difference or importance of differing tube types. Mixing tube types within fittings improves the color reproduction of lower quality tubes. Tax incentives and environmental awareness result in higher use in places such as California. This article is about the U.S state. ...


In other countries, residential use of fluorescent lighting varies depending on the price of energy, financial and environmental concerns of the local population, and acceptability of the light output. In East and Southeast Asia it is very rare to see incandescent bulbs in buildings anywhere. This article is about the geographical region. ... Location of Southeast Asia Southeast Asia is a subregion of Asia. ... Incandescence is the release of electromagnetic radiation from a hot body due to its high temperature. ...


In February 2007, Australia enacted a law that will ban most sales of incandescent light bulbs by 2010.[4] While the law does not specify which alternative Australians are to use, compact fluorescents are likely to be the primary replacements. In April 2007, Canada announced a similar plan to phase out the sale of incandescent bulbs by 2012. Finnish parliament has been discussing banning sales of incandescent light bulbs by the beginning of 2011.[5]


Advantages

Efficiency

Fluorescent lamps are more efficient than incandescent light bulbs of an equivalent brightness. This is because a greater proportion of the power used is converted to usable light and a smaller proportion is converted to heat, allowing fluorescent lamps to run cooler. A typical 100 Watt tungsten filament incandescent lamp may convert only 10% of its power input to visible white light, whereas typical fluorescent lamps convert about 22% of the power input to visible white light [6] - see the table in the luminous efficacy article. Lighting efficiency is a measure of how much visible light is given off from a light source per unit of energy. ... The incandescent light bulb or incandescent lamp is a source of artificial light that works by incandescence, (a general term for heat-driven light emissions which includes the simple case of black body radiation). ... For other uses, see Light (disambiguation). ... For other uses, see Heat (disambiguation) In physics, heat, symbolized by Q, is energy transferred from one body or system to another due to a difference in temperature. ... Luminous efficacy is a property of light sources, which indicates what portion of the emitted electromagnetic radiation is usable for human vision. ...


Life

Typically a fluorescent lamp will last between 10 to 20 times as long as an equivalent incandescent lamp when operated several hours at a time.


The higher initial cost of a fluorescent lamp is usually more than compensated for by lower energy consumption over its life. The longer life may also reduce lamp replacement costs, providing additional saving especially where labour is costly. Therefore they are widely used by businesses and institutions, but not as much by households.


Lower luminosity

Compared with an incandescent lamp, a fluorescent tube is a more diffuse and physically larger light source. In suitably designed lamps, light can be more evenly distributed without point source of glare such as seen from an undiffused incandescent filament.


Lower heat

About two-thirds to three-quarters less heat is given off by fluorescent lamps compared to an equivalent installation of incandescent lamps. This greatly reduces the size, cost, and energy consumption of air-conditioning equipment.

The "beat effect" problem created when shooting photos or film under standard fluorescent lighting.
The "beat effect" problem created when shooting photos or film under standard fluorescent lighting.

Image File history File linksMetadata Fluorescentfixturebelow20806. ... Image File history File linksMetadata Fluorescentfixturebelow20806. ...

Disadvantages

Health issues

If a fluorescent lamp is broken, mercury can contaminate the surrounding environment. A 1987 report described a 23-month-old toddler hospitalized due to mercury poisoning traced to a carton of 8-foot fluorescent lamps that had broken. The glass was cleaned up and discarded, but the child often used the area for play.[7] It has been suggested that Acrodynia be merged into this article or section. ...


Fluorescent lamps can cause problems among individuals with pathological sensitivity to ultraviolet light. They can induce disease activity in photosensitive individuals with Systemic lupus erythematosus; standard acrylic diffusers absorb UV-B radiation and appear to protect against this.[8] In rare cases individuals with solar urticaria (allergy to sunlight) can get a rash from fluorescent lighting.[9] However, no fluorescent lighting technology presents anywhere near the high levels of UV danger to light sensitive persons that sunlight presents. A recent study in the US found that UV exposure from sitting under typical office fluorescent lights for eight continuous hours is equivalent to just over one minute of sun exposure (Lytle et al An Estimation of Squamous Cell Carcinoma Risk from Ultraviolet Radiation Emitted by Fluorescent Lamps; Photodermatol Photoimmunol Photomed (1993))


Elimination of fluorescent lighting is appropriate for several conditions. In addition to causing headache and fatigue,[10] and problems with light sensitivity,[11] they are listed as problematic for individuals with epilepsy,[12] lupus,[13] chronic fatigue syndrome, and vertigo[14] (related to cardiovascular problems, MS, and several other disorders.[citation needed]) Research on this is very limited. A headache (cephalgia in medical terminology) is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. ... Exhaustion redirects here. ... // Wolf (latin). ... Chronic fatigue syndrome (CFS) is one of several names given to a poorly understood, highly debilitating disorder of uncertain cause/causes, which is thought to affect approximately 4 per 1,000 adults[1] in the United States and other countries, and a smaller fraction of children. ... Vertigo, a specific type of dizziness, is a major symptom of a balance disorder. ...


Ballasts

Magnetic single-lamp ballasts have a low power factor
Magnetic single-lamp ballasts have a low power factor

Fluorescent lamps require a ballast to stabilize the lamp and to provide the initial striking voltage required to start the arc discharge. This increases the cost of fluorescent light fixtures, though often one ballast is shared between two or more lamps. Electromagnetic ballasts with a minor fault can produce an audible humming or buzzing noise. The power factor of an AC electric power system is defined as the ratio of the real power to the apparent power, and is a number between 0 and 1. ... A chandelier light fixture A light fixture or luminaire is an electrical device used to create artificial light or illumination in architecture. ...


Power factor

Simple inductive fluorescent lamp ballasts have a power factor of less than unity. Inductive ballasts include power factor correction capacitors. The power factor of an AC electric power system is defined as the ratio of the real power to the apparent power, and is a number between 0 and 1. ...


Power harmonics

Fluorescent lamps are a non-linear load and generate harmonics on the electrical power supply. This can generate radio frequency noise in some cases. Suppression of harmonic generation is standard practice, but imperfect. Very good suppression is possible, but adds to the cost of the fluorescent fixtures.


Optimum operating temperature

Fluorescent lamps operate best around room temperature. At much lower or higher temperatures, efficiency decreases and at low temperatures (below freezing) standard lamps may not start. Special lamps may be needed for reliable service outdoors in cold weather. A "cold start" electrical circuit was also developed in the mid-1970s.


Non-compact light source

Because the arc is quite long relative to higher-pressure discharge lamps, the amount of light emitted per unit of surface of the lamps is low, so tube lamps were large compared with incandescent sources. However, in many cases low luminous intensity of the emitting surface was useful because it reduced glare. The bulk created by this lamp affected the design of fixtures since light must be directed from long tubes instead of a compact source. Glare is difficulty seeing in the presence of bright light such as direct or reflected sunlight or artificial light such as car headlamps at night. ...


Recently, a new type of fluorescent lamp, the CFL, has been introduced to address this issue and allow regular incandescent sockets to be fitted with this type of lamp, thereby negating the need to mount it on special fixtures. However, some CFLs intended to replace incandescents will not fit some desk lamps, because the harp (heavy wire shade support bracket) is shaped for the narrow neck of an incandescent lamp. CFLs tend to have a wide housing for their electronic ballast close to the lamp's base, too wide to fit. Low-energy light-bulb redirects here. ...


Flicker problems

Older fluorescent fittings using an electromagnetic mains frequency ballast do not give out a steady light; instead, they flicker (fluctuate in intensity) at twice the supply frequency. While this is not easily discernible by the human eye, it can cause a strobe effect, where something spinning at just the right speed may appear stationary if illuminated solely by a single fluorescent lamp. This effect is entirely eliminated by paired lamps operating on a lead-lag ballast. Unlike a true strobe lamp, the light level drops in appreciable time and so substantial "blurring" of the moving part would be evident. Temporal aliasing is the technical term for a phenomenon also known as the stroboscopic effect or the wagon-wheel effect. ...


Electromagnetic ballasts may also cause problems for video recording as there can be a 'beat effect' between the periodic reading of a camera's sensor and the fluctuations in intensity of the fluorescent lamp. When other devices that also flicker, such as CRT-based computer monitors, are operated under fluorescent lighting, the flicker may become much more noticeable. Cathode ray tube employing electromagnetic focus and deflection Cutaway rendering of a color CRT: 1. ...


Incandescent lamps, due to the thermal inertia of their element, fluctuate to a lesser extent at common power frequencies. Full-size and compact fluorescent lamps using high-frequency electronic ballasts do not produce visible light flicker, since the phosphor persistence is longer than a half cycle of the higher operation frequency. Operating frequencies of electronic ballasts are selected to avoid interference with infrared remote controls. The incandescent light bulb uses a glowing wire filament heated to white-hot by electrical resistance, to generate light (a process known as thermal radiation). ... Volumetric heat capacity (VHC) describes the ability of a given volume of a substance to store heat while undergoing a given temperature change, but without undergoing a phase change. ... The waveform of 230 volt, 50 Hz compared with 110 V, 60 Hz. ...


The non-visible 100 Hz - 120 Hz flicker from fluorescent tubes powered by electromagnetic ballasts are associated with headaches and eyestrain. Individuals with high flicker fusion threshold are particularly affected by electromagnetic ballasts: their EEG alpha waves are markedly attenuated and they perform office tasks with greater speed and decreased accuracy. [15] Ordinary people have better reading performance using high frequency (20 kHz – 60 kHz) electronic ballasts than electromagnetic ballasts.[16] The flicker fusion threshold (or flicker fusion rate) is a concept in the psychophysics of vision. ...


The flicker of fluorescent lamps, even with electromagnetic ballasts, is so rapid that it is unlikely to present a hazard to individuals with epilepsy.[17] Early studies suspected a relationship between the flickering of fluorescent lamps with electromagnetic ballasts and repetitive movement in autistic children.[18] However, these studies had interpretive problems[19] and have not been replicated. Stereotypy is a behavioral condition characterized by either a lack of variation in patterns of thought, motion and speech, by repitition of said patterns, or both. ... A boy with autism and his mother Autism refers to a spectrum of disorders, and lies somewhere under the umbrella of a greater encompassing spectrum, that of pervasive developmental disorders that involve the functioning of the brain. ...


Color rendition

The issues with color faithfulness of some tube types are discussed above.


Dimming

Fluorescent light fixtures cannot be connected to a standard dimmer switch used for incandescent lamps. Two effects are responsible for this: the waveshape of the voltage emitted by a standard phase-control dimmer interacts badly with many ballasts and it becomes difficult to sustain an arc in the fluorescent tube at low power levels. Many installations require 4-pin fluorescent lamps and compatible dimming ballasts for successful fluorescent dimming. These systems keep the cathodes of the fluorescent tube fully heated even as the arc current is reduced, promoting easy thermionic emission of electrons into the arc stream. CFLs are available that work in a dimmer circuit. A common dual dimmer manufactured by Electronic Theatre Controls (ETC) Another dimmer by Colortran Dimmers are devices used to vary the brightness of a light. ...


Disposal and recycling

The disposal of phosphor and particularly the mercury in the tubes is an environmental issue. Mercury poses the greatest hazard to pregnant women, infants, and children. Governmental regulations in many areas require special disposal of fluorescent lamps separate from general and household wastes. For large commercial or industrial users of fluorescent lights, recycling services are available in many nations, and may be required by regulation. In some areas, recycling is also available to consumers. The need for a recycling infrastructure is an issue with instituting proposed bans of incandescent bulbs. This article is about the element. ...


The amount of mercury in a standard lamp can vary dramatically, from 3 to 46 mg.[20] Newer lamps contain less mercury and the 3-4 mg versions are sold as low-mercury types. A typical 2006-era 4 ft (122 cm) T-12 fluorescent lamp (i.e., F32T12) contains about 12 milligrams of mercury.[21] In early 2007, the National Electrical Manufacturers Association in the US announced that "Under the voluntary commitment, effective April 15, 2007, participating manufacturers will cap the total mercury content in CFLs under 25 watts at 5 milligrams (mg) per unit. CFLs that use 25 to 40 watts of electricity will have total mercury content capped at 6 mg per unit."[22] The milligram (symbol mg) is an SI unit of mass. ...


A broken fluorescent tube is more hazardous than a broken conventional incandescent bulb due to the mercury content. Because of this, the safe cleanup of broken fluorescent bulbs differs from cleanup of conventional broken glass or incandescent bulbs. 99% of the mercury is typically contained in the phosphor, especially on lamps that are near their end of life.[23]


At least some of the early (around 1940) fluorescent lamps used compounds containing beryllium, a toxic element. [24]. However, it is very unlikely that one would encounter any such lamps.[25]


Tube designations

Lamps are typically identified by a code such as F##T##, where F is for fluorescent, the first number indicates the power in watts (or where lamps can be operated at different power levels, the length in inches), the T indicates that the shape of the bulb is tubular, and the last number is the diameter in eighths of an inch (sometimes in millimeters, rounded to the nearest millimeter). Typical diameters are T12 or T38 (11/2" Ø or 38.1 mm Ø) for residential bulbs with old magnetic ballasts, T8 or T26 (1" Ø or 25.4 mm Ø) for commercial energy-saving lamps with electronic ballasts, and T5 or T16 (5/8" Ø or 15.875 mm Ø) for very small lamps which may even operate from a battery powered device. Image File history File links Gnome-globe. ... North American redirects here. ... Identification can mean The act of identifying. ... In communications, a code is a rule for converting a piece of information (for example, a letter, word, or phrase) into another form or representation, not necessarily of the same type. ... An inch (plural: inches; symbol or abbreviation: in or, sometimes, ″ - a double prime) is the name of a unit of length in a number of different systems, including English units, Imperial units, and United States customary units. ... Look up Tube in Wiktionary, the free dictionary. ... DIAMETER is a computer networking protocol for AAA (Authentication, Authorization and Accounting). ... For other uses, see Magnet (disambiguation). ... An automotive (ignition system) ballast resistor An electrical ballast (sometimes called control gear) is a device intended to limit the amount of current flowing in an electric circuit. ...

Fluorescent tube diameter designation comparison
Tube Diameter Designations Tube Diameter Measurements
Imperial-based Metric-based Inches Ø

(")

Millimeters Ø

(mm)

T5 T16 5/8" Ø 15.875 mm Ø
T8 T26 8/8" Ø 1" Ø 25.4 mm Ø
T9 * T29 * 9/8" Ø * 11/8" Ø * 28.575 mm Ø *
T12 T38 12/8" Ø 11/2" Ø 38.1 mm Ø
PG17 ** N/A ** 17/8" Ø ** 21/8" Ø ** 53.975 mm Ø **
* - Circular fluorescent tubes only

** - General Electric's Power Groove® tubes only GE redirects here. ...

Reflectors

Some lamps are designed with a reflector built inside the lamp. This is done by pouring an opaque coating into the lamp first, rotating the lamp to achieve the desired amount of coverage, then allowing it to dry before adding the traditional phosphors. With straight lamps, this is commonly poured in a fashion as to cover half the lamp as it is lying flat, with the lamp rated as to the amount of curvature that is covered in the opaque coating. A 180 degree lamp has 50% coverage, whereas a 210 degree lamp has 30 degrees more coverage. These are the most common type, although the reflector can vary from 120 degrees to well over 310 degrees. Lamps that have significantly more than 210 degrees of coverage are often referred to as "aperature lamps" as the amount of open area that light can escape is significantly less than the area that acts as an internal reflector. Often, a lamp is marked as a reflector lamp by adding the letter "R" in the model code, so a F##T##HO lamp with a reflector would be coded as "FR##T##HO". VHO lamps with reflectors may be coded as VHOR. No such designation exists for the amount of reflector degrees the lamp has.


Reflector lamps are used in several application, particularly when light is only desired to be emitted in a single direction, or when an application requires the maximum amount of light. This can be as simple as in a higher end tanning bed or in some backlighting situation for electronics. An internal reflector is more efficient than standard external reflectors as there is less opportunity to lose light due to wave cancellation. Another example is color matched aperature lights (330 degrees of opening, give or take) are used in the food industry for quality control purposes, to allow robotic inspection of cooked goods. A sunbed, with lights off. ...


Slimline lamps

Slimline lamps operate on an instant start ballast and are recognizable by their single-pin bases.


Light outputs

High-output lamps are brighter and draw more electrical current, have different ends on the pins so they cannot be used in the wrong fixture, and are labeled F##T##HO, or F##T##VHO for very high output. Since about the early to mid 1950s to today, General Electric developed and improved the Power Groove® lamp with the label F##PG17. These lamps are recognizable by their large diameter (17/8" or 21/8"), grooved tube shape and an R17d cap on each end of them. Output is the term denoting either an exit or changes which exits a system and which activate/modify a process. ... In electricity, current is the rate of flow of charges, usually through a metal wire or some other electrical conductor. ... Look up pin in Wiktionary, the free dictionary. ... In the law of real property, fixtures are anything that would otherwise be a chattel that have, by reason of incorporation or affixation, become permanently attached to the real property. ...


Other tube shapes

U-shaped tubes are FB##T##, with the B meaning "bent". Most commonly, these have the same designations as linear tubes. Circular bulbs are FC##T#, with the diameter of the circle (not circumference or watts) being the first number, and the second number usually being 9 (29 mm) for standard fixtures. The circumference is the distance around a closed curve. ...


Colors

Color is usually indicated by WW for warm white, EW for enhanced (neutral) white, CW for cool white (the most common), and DW for the bluish daylight white. BLB is used for blacklight-blue lamps commonly used in bug zappers. BL is used for blacklight lamps commonly used in nightclubs. Other non-standard designations apply for plant lights or grow lights. Look up daylight in Wiktionary, the free dictionary. ... A Bug Zapper A bug zapper is a device that attracts and kills insects that are attracted by light. ... BlackLight Is a Rock Band set up April 2006. ... Grow lights are electric lamps designed to promote plant growth by emitting an electromagnetic spectrum appropriate for photosynthesis. ... Dual spectrum compact fluorescent grow light. ...


Philips and Osram use numeric color codes for the colors. On Tri-Phosphor and Multi-Phosphor tubes, the first digit indicates the Color Rendition Index of the lamp. If the first digit on a lamp says 8, then the CRI of that lamp will be approximately 85. The last two digits indicate the Color Temperature of the lamp in Kelvins (K). For example, if the last two digits on a lamp say 40, that lamp's Color Temperature will be 4000 K, which is a common Tri-Phosphor Cool White fluorescent lamp. Philips HQ in Amsterdam Koninklijke Philips Electronics N.V. (Royal Philips Electronics N.V.), usually known as Philips, (Euronext: PHIA, NYSE: PHG) is one of the largest electronics companies in the world, founded and headquartered in the Netherlands. ... This article or section does not cite its references or sources. ... The CIE 1931 x,y chromaticity space, also showing the chromaticities of black-body light sources of various temperatures, and lines of constant correlated color temperature Color temperature is a characteristic of visible light that has important applications in photography, videography, publishing and other fields. ...

Halophosphate tubes
Numeric Color Code Color Approximate Color Rendition Index Color Temperature (K)
27 Warm White 50 - 79 2700
33 Cool White 50 - 79 4000
54 Cool Daylight 50 - 79 6000
Tri-Phosphor tubes
Numeric Color Code Color Approximate Color Rendition Index Color Temperature (K)
827 Warm White ~85 2700
840 Cool White ~85 4000
865 Cool Daylight ~85 6500
Multi-Phosphor tubes
Numeric Color Code Color Approximate Color Rendition Index Color Temperature (K)
927 Warm White ~95 2700
940 Cool White ~95 4000
965 Cool Daylight ~95 6500
Special purpose tubes
Numeric Code Fluorescent

lamp type

Notes
05 Germicidal lamps No phosphors used at all,

using an envelope of fused quartz. A 9W germicidal lamp in a modern compact fluorescent lamp form factor Close-up of the electrodes and the safety warning An EPROM. The small quartz window admits UV light during erasure. ... A sphere manufactured by NASA out of fused quartz for use in a gyroscope in the Gravity Probe B experiment. ...

08 Black light lamps
09 Sun Tanning lamps

Spectrum of a fluorescent black light source. ... Typical tanning lamp with F71T12 markings. ...

Lengths

Odd lengths are usually added after the color. One example is an F25T12/CW/33, meaning 25 Watts, 11/2" diameter, Cool White, 33" or 84 cm long. Without the 33", it would be assumed that an F25T12 is the more-common 30" long.


Compact Fluorescent Lamps

Some compact fluorescents are now being labelled with this designation system.


Other fluorescent lamps

Blacklights
Blacklights are a subset of fluorescent lamps that are used to provide long-wave ultraviolet light (at about 360nm wavelength). They are built in the same fashion as conventional fluorescent lamps but the glass tube is coated with a phosphor that converts the short-wave UV within the tube to long-wave UV rather than to visible light. They are used to provoke fluorescence (to provide dramatic effects using blacklight paint and to detect materials such as urine and certain dyes that would be invisible in visible light) as well as to attract insects to bug zappers.
So-called blacklite blue lamps are also made from more expensive deep purple glass known as Wood's glass rather than clear glass. The deep purple glass filters out most of the visible colors of light directly emitted by the mercury-vapor discharge, producing proportionally less visible light compared with UV light. This allows UV-induced fluorescence to be seen more easily (thereby allowing blacklight posters to seem much more dramatic). The blacklight lamps used in bug zappers do not require this refinement so it is usually omitted in the interest of cost; they are called simply blacklite (and not blacklite blue).
Tanning lamps
The lamps used in tanning beds contain a different phosphor blend (typically 3 to 5 or more phosphors) that emits both UVA and UVB, provoking a tanning response in most human skin. Typically, the output is rated as 3% to 10% UVB (5% most typical) with the remaining UV as UVA. These are mainly F71, F72 or F73 HO (100W) lamps, although 160W VHO are somewhat common.
Grow lamps
Grow lamps contain a phosphor blend that encourages photosynthesis in plants; they usually appear pinkish to human eyes.
Germicidal lamps
Germicidal lamps contain no phosphor at all (technically making them gas discharge lamps rather than fluorescent) and their tubes are made of fused quartz that is transparent to the short-wave UV directly emitted by the mercury discharge. The UV emitted by these tubes will kill germs, ionize oxygen to ozone, and cause eye and skin damage. Besides their uses to kill germs and create ozone, they are sometimes used by geologists to identify certain species of minerals by the color of their fluorescence. When used in this fashion, they are fitted with filters in the same way as blacklight-blue lamps are; the filter passes the short-wave UV and blocks the visible light produced by the mercury discharge. They are also used in EPROM erasers.
Germicidal lamps have designations beginning with G (meaning 'Germicidal'), rather than F, for example G30T8 for a 30-Watt, 1 inch diameter, 36 inch long germicidal lamp (as opposed to an F30T8, which would be the fluorescent lamp of the same size and rating).
Electrodeless induction lamps
Electrodeless induction lamps are fluorescent lamps without internal electrodes. They have been commercially available since 1990. A current is induced into the gas column using electromagnetic induction. Because the electrodes are usually the life-limiting element of fluorescent lamps, such electrodeless lamps can have a very long service life, although they also have a higher purchase price.
Compact fluorescent lamps (CFL)
Also known as a compact fluorescent light bulb is a type of fluorescent lamp designed to replace an incandescent lamp. Many CFLs can fit in the existing incandescent light fixtures.
Cold-cathode fluorescent lamps (CCFL)
Cold-cathode fluorescent lamps are used as backlighting for LCD displays in personal computer and TV monitors. They are also popular with case modders in recent years.

BlackLight Is a Rock Band set up April 2006. ... For other uses, see Ultraviolet (disambiguation). ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... Blacklight paint or blacklight-reactive paint is paint that glows under a blacklight (a source of light whose wavelengths are primarily in the ultraviolet range). ... This article is about the urine of animals generally. ... Look up dye in Wiktionary, the free dictionary. ... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera... A Bug Zapper A bug zapper is a device that attracts and kills insects that are attracted by light. ... Spectrum of a fluorescent black light source. ... A black light bulb. ... A Bug Zapper A bug zapper is a device that attracts and kills insects that are attracted by light. ... Wikipedia does not yet have an article with this exact name. ... Typical tanning lamp with F71T12 markings. ... A sunbed, with lights off. ... A woman sunbathing A suntanned arm showing browner skin where it has been exposed. ... This article is about modern humans. ... This article is about the organ. ... Grow lights are electric lamps designed to promote plant growth by emitting an electromagnetic spectrum appropriate for photosynthesis. ... A 9W germicidal lamp in a modern compact fluorescent lamp form factor Close-up of the electrodes and the safety warning An EPROM. The small quartz window admits UV light during erasure. ... A sphere manufactured by NASA out of fused quartz for use in a gyroscope in the Gravity Probe B experiment. ... This article is about the chemical element and its most stable form, or dioxygen. ... For other uses, see Ozone (disambiguation). ... Germ can mean: Microorganism, especially a pathogenic one; see Germ theory of disease. ... The Geologist by Carl Spitzweg A geologist is a contributor to the science of geology, studying the physical structure and processes of the Earth and planets of the solar system (see planetary geology). ... For other uses, see Mineral (disambiguation). ... EPROM. The small quartz window admits UV light during erasure. ... In contrast with all other electrical lamps that use electrical connections through the lamp envelope to transfer power to the lamp, in electrodeless lamps the power needed to generate light is transferred from the outside of the lamp envelope by means of (electro)magnetic fields. ... This article is about the year. ... For magnetic induction, see Magnetic field. ... Low-energy light-bulb redirects here. ... A cold cathode is an element used within some Nixie tubes, gas discharge lamps, gas filled tubes, and vacuum tubes. ... Backlighting refers to a technique used to make flat panel displays easier to read. ... LCD redirects here. ... This article or section is not written in the formal tone expected of an encyclopedia article. ...

Science demonstrations

Fluorescent lamps can be illuminated by means other than a proper electrical connection. These other methods however result in very dim or very short-lived illumination, and so are seen mostly in science demonstrations. With the exception of static electricity, these methods can be very dangerous if done improperly:

Static electricity is a class of phenomena involving the net charge present on an object; typically referring to charged object with voltages of sufficient magnitude to produce visible attraction, repulsion, and sparks. ... Van de Graf generator. ... Tesla Coil at Questacon, the Australian National Science Centre museum A Tesla coil (also teslacoil) is a type of resonant transformer, named after its inventor, Nikola Tesla. ... In electronics, capacitive coupling is the transfer of energy from one circuit to another by means of the mutual capacitance between the circuits. ... Power line redirects here. ...

Film and video use

Special fluorescent lights are often used in film and video production. The brand name Kino Flo are used to create softer fill light and are less hot than traditional halogen light sources. These fluorescent lights are designed with special high-frequency ballasts to prevent video flickering and high color-rendition index bulbs to approximate daylight color temperatures.


See also

A Common Household Light bulb This is a list of sources of light, including both natural and artificial sources, and both processes and devices. ... An automotive (ignition system) ballast resistor An electrical ballast (sometimes called control gear) is a device intended to limit the amount of current flowing in an electric circuit. ...

References

  1. ^ U.S. Patent 865367 Fluorescent Electric Lamp
  2. ^ General Electric Fluorescent Lamps TP 111R, Dec. 1978, page 22
  3. ^ Klipstein, Donald L.. Light and Lighting Facts and Bits of Data!. Retrieved on 2007-12-29.
  4. ^ Australia Bans Traditional Light Bulbs to Combat Global Warming. green wombat blog (2007-02-20). Retrieved on 2007-12-31.
  5. ^ Ban on incandescent lamps discussed by Finnish Parliament. Helsingin Sanomat - International Edition (2007-09-27). Retrieved on 2007-12-31.
  6. ^ General Electric Fluorescent Lamps TP111R, page 20
  7. ^ Tunnessen WW Jr, McMahon KJ, Baser M (1987). "Acrodynia: exposure to mercury from fluorescent light bulbs". Pediatrics 79 (5): 786–9. PMID 3575038. 
  8. ^ Rihner M, McGrath H Jr (1992). "Fluorescent light photosensitivity in patients with systemic lupus erythematosus". Arthritis Rheum 35 (8): 949–52. doi:10.1002/art.1780350816. PMID 1642660. 
  9. ^ Beattie PE, Dawe RS, Ibbotson SH, Ferguson J (2003). "Characteristics and prognosis of idiopathic solar urticaria: a cohort of 87 cases". Arch Dermatol 139 (9): 1149–54. doi:10.1001/archderm.139.9.1149. PMID 12975156. 
  10. ^ Accommodation and Compliance Series: Employees with Chronic Fatigue Syndrome
  11. ^ Working with Light Sensitivity
  12. ^ Accommodation Ideas for Employees with Epilepsy
  13. ^ Accommodation and Compliance Series: Employees with Lupus
  14. ^ Accommodating People with Vertigo
  15. ^ Küller R, Laike T (1998). "The impact of flicker from fluorescent lighting on well-being, performance and physiological arousal". Ergonomics 41 (4): 433–47. doi:10.1080/001401398186928. 
  16. ^ Veitch JA, McColl SL (1995). "Modulation of fluorescent light: flicker rate and light source effects on visual performance and visual comfort". Light Res Tech 27 (4): 243–256. Retrieved on 2007-08-12. 
  17. ^ Binnie CD, de Korte RA, Wisman T (1979). "Fluorescent lighting and epilepsy". Epilepsia 20 (6): 725–7. doi:10.1111/j.1528-1157.1979.tb04856.x. PMID 499117. 
  18. ^ Colman RS, Frankel F, Ritvo E, Freeman BJ (1976). "The effects of fluorescent and incandescent illumination upon repetitive behaviors in autistic children". J Autism Child Schizophr 6 (2): 157–62. doi:10.1007/BF01538059. PMID 989489. 
  19. ^ Turner M (1999). "Annotation: Repetitive behaviour in autism: a review of psychological research". J Child Psychol Psychiatry 40 (6): 839–49. doi:10.1017/S0021963099004278. PMID 10509879. 
  20. ^ Page 183 of http://www.chem.unep.ch/MERCURY/Toolkit/UNEP-final-pilot-draft-toolkit-Dec05.pdf
  21. ^ Lighting Design Lab Articles - Mercury in Fluorescent Lamps
  22. ^ NEMA Voluntary Commitment on Mercury in CFLs
  23. ^ Floyd, et al. (2002), quoted on page 184 of Toolkit for identification and quantification of mercury releases (PDF)
  24. ^ http://www.nyu.edu/classes/jaeger/beryllium.htm Beryllium toxicity and fluorescent lamp manufacture, retrieved June 7,2008
  25. ^ General Electric Fluorescent Lamps TP 111R, Dec. 1978, says on pg. 23 that since 1949 GE lamps used relatively inert phosphates found to be safe in ordinary handling of either the intact or broken lamp.
  26. ^ richardbox.com

Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 363rd day of the year (364th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 51st day of the year in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 365th day of the year (366th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 270th day of the year (271st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 365th day of the year (366th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 224th day of the year (225th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... “PDF” redirects here. ...

External links

Wikimedia Commons has media related to:
Fluorescent lamp
  • NASA: The Fluorescent Lamp: A plasma you can use
  • How Stuff Works: Are fluorescent bulbs really more efficient than normal light bulbs?
  • How Stuff Works: How Fluorescent Lamps Work
  • Sam's F-Lamp FAQ
  • The Fluorescent Lighting System
  • The Lighting Design Lab: Should I Turn Off Fluorescent Lighting When Leaving A Room?
  • Museum of Electric Lamp Technology
  • Application notes for CCFL lamps.
  • History, Science and Technology of Light Sources
  • R. N. Thayer (1991-10-25). The Fluorescent Lamp: Early U. S. Development. The Report courtesy of General Electric Company. Retrieved on 2007-03-18.
  • Dozens of raw visible spectra of fluorescent and other light bulbs
  • Fluorescent Lighting, UK.D-I-Y Wiki
  • What to Do if a Fluorescent Light Bulb Breaks
  • Fluorescent Tubes in the Workplace Article explaining the proper disposal of fluorescent tubes
  • 'Energy saving lightbulbs'
Year 1991 (MCMXCI) was a common year starting on Tuesday (link will display full calendar) of the Gregorian Calendar. ... is the 298th day of the year (299th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 77th day of the year (78th in leap years) in the Gregorian calendar. ... For devices such as table lamps and reading lamps, see Light fixture. ... Not to be confused with lightning. ... Molten glassy material glows orange with incandescence in a vitrification experiment. ... The incandescent light bulb or incandescent lamp is a source of artificial light that works by incandescence, (a general term for heat-driven light emissions which includes the simple case of black body radiation). ... The incandescent light bulb uses a glowing wire filament heated to white-hot by electrical resistance, to generate light (a process known as thermal radiation). ... A Parabolic Aluminized Reflector light, or PAR light, is a type of light commonly used in motion picture production when a substantial amount of light is required for a scene. ... Nernst lamp, complete, model B with cloche, DC-lamp 0. ... The Centennial Light hanging in the Livermore, California Firehouse. ... Image File history File links Size of this preview: 361 × 600 pixelsFull resolution (768 × 1276 pixel, file size: 757 KB, MIME type: image/png) Other versions Original at Image:Gluehlampe 01 KMJ.jpg File historyClick on a date/time to view the file as it appeared at that time. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... Low-energy light-bulb redirects here. ... In contrast with all other electrical lamps that use electrical connections through the lamp envelope to transfer power to the lamp, in electrodeless lamps the power needed to generate light is transferred from the outside of the lamp envelope by means of (electro)magnetic fields. ... 15 kW Xenon short-arc lamp used in IMAX projectors High-intensity discharge (HID) lamps include these types of electrical lamps: mercury vapor, metal halide (also HQI), high-pressure sodium (Son), low-pressure sodium (Sox) and less common, xenon short-arc lamps. ... A Mercury-vapor lamp is a gas discharge lamp which uses mercury in an excited state to produce light. ... Example of a light source using a broad spectrum metal halide lamp pointing upward towards the sky. ... Ceramic Discharge Metal Halide lamps are a relativly new source of light that is a variation of the Mercury-vapor lamp. ... A low pressure sodium/sodium oxide (LPS/SOX) streetlamp at full power A low pressure sodium/sodium oxide (LPS/SOX) streetlamp at full power (detail) A sodium vapor lamp is a gas discharge lamp which uses sodium in an excited state to produce light. ... Germicidal lamps are simple low pressure mercury vapor discharges in a fused quartz envelope. ... Lighting neon lamp, two 220/230 volt and 110 V neon lamps and a screwdriver with neon lamp inside A neon lamp is a gas discharge lamp containing primarily neon gas at low pressure. ... This section may require cleanup to meet Wikipedias quality standards. ... Xenon flash lamp being fired. ... This article is about light sources and indicators. ... Spectrum of a fluorescent black light source. ... Typical tanning lamp with F71T12 markings. ... A 9W germicidal lamp in a modern compact fluorescent lamp form factor Close-up of the electrodes and the safety warning An EPROM. The small quartz window admits UV light during erasure. ... Dual spectrum compact fluorescent grow light. ... 15 kW Xenon short-arc lamp. ... The 300,000-watt Plasma Arc Lamp in the Infrared Processing Center (IPC) at Oak Ridge National Laboratory An arc lamp is a device that produces light by the sparking (or arcing, from voltaic arc) of a high current between two carbon rod electrodes. ... A Yablochkov candle (sometimes electric candle) is a type of electric carbon arc lamp, invented in 1876 by Pavel Yablochkov. ... This article is about the chemical reaction combustion. ... Lit carbide lamp A French manufactured Carbide of Calcium lamp on a bicycle Carbide of Calcium lamp in a coal mine Carbide lamps also known as Acetylene Gas lamps are simple lamps that produce and burn acetylene gas (C2H2) which is created by the reaction of calcium carbide (CaC2) with... The Argand lamp was invented and patented in 1780 by Aimé Argand . ... For other uses, see Candle (disambiguation). ... The Indian light festival Diwali is traditionally lit up by huge numbers of Diya (plural diyas). Diya is a contracted form of deep or light given by small earthen pots (also known as Pradeep), with wick made of cotton and dipped in ghee. ... Gas lighting is the process of burning piped natural gas or coal gas for illumination. ... Swiss kerosene lamp. ... For other uses, see Lantern (disambiguation). ... This article does not cite any references or sources. ... Antique bronze oil lamp with Christian symbol (replica) A terra-cotta oil lamp, Antique oil lamp (replica) An oil lamp is a simple vessel used to produce light continuously for a period of time from a fuel source. ... Safety lamp is the name of a variety of lamps for safety in coal-mines against coal dust, methane, or firedamp, a highly explosive mixture of natural gas apt to accumulate in them. ... A Rushlight is a type of candle formed using the dried pith of the rush plant as its wick. ... Tilley Lamp TL10 from 1922-1946 The Tilley Lamp derives from John Tilley’s invention of the hydro-pneumatic blowpipe in 1813. ... This article is about portable open fires. ... LBNL researcher examines prototype sulfur lamp. ... LED redirects here. ... LED Lamp with GU10 twist lock fitting, intended to replace halogen reflector lamps. ... Solid State Lighting (SSL) refers to a type of lighting that utilizes light-emitting diodes (LEDs), organic light-emitting diodes (OLED), or polymer light-emitting diodes as sources of illumination rather than electrical filaments or gas. ... Emission spectrum of an ultraviolet deuterium arc lamp clearly showing characteristic hydrogen emission lines (sharp peaks at 656 nm and 486 nm) and continuum emission in the ~160-400 nm region. ... This article or section does not cite its references or sources. ... Electroluminescent wire (often abbreviated to EL wire) is a thin copper wire coated in a phosphor which glows when an AC voltage is applied to it. ... A chemoluminescent reaction carried out in an erlenmeyer flask producing a large amount of light. ... Radioluminescence is the phenomenon by which luminescence is produced in a material by the bombardment of ionizing radiation such as beta particles. ... Artificial sunlight is the use of a light bulb to emulate the power of the sun. ...

  Results from FactBites:
 
Fluorescent lamp for unipolar mode of operation - Patent 4814663 (1169 words)
The fluorescent lamp according to claim 1, characterized in that the anode (8) is connected to at least two heat dissipators (9', 9") of a material having a high thermal conductivity for carrying off of the heat from the lamp outwardly.
A fluorescent lamp according to claim 1, 2 or 3, in particular for the reproduction of alphanumeric characters (letters and numbers) and images within the scope of a display matrix, characterized in that the cathode is externally and permanently heated.
Such a fluorescent lamp is filled predominantly with mercury vapour, while the inner face of the glass envelope thereof is coated with a fluorescent material.
Fluorescent Lamp (453 words)
While the phrase fluorescent lamp may not be the appropriate term technically, it is called so because of the fluorescent coating inside the bulb that converts the ultraviolet light created by the bulb into a visible light that is visible to that naked eye.
The fluorescent lamp was first made commercially available in the 1920’s, the fluorescent lamp is now being used extensively in all the fields of energy applications.
Fluorescent lamps are good for human health, but in some case these have been found to pose a serious health hazards in women who are pregnant, children, and infants.
  More results at FactBites »

 
 

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