NationMaster - Encyclopedia: Black light

Black light (also Wood's light) is the common name for a lamp emitting electromagnetic radiation that is almost exclusively in the soft near ultraviolet range, and very little visible light. In many areas this type of lighting is more commonly referred to as simply "UV light". Image File history File links Download high resolution version (1284x827, 18 KB) Summary Spectrum of light from a fluorescent black light with peaks labelled. ... Image File history File links Download high resolution version (1284x827, 18 KB) Summary Spectrum of light from a fluorescent black light with peaks labelled. ... In telecommunication, a full width at half maximum (FWHM) is an expression of the extent of a function, given by the difference between the two extreme values of the independent variable at which the dependent variable is equal to half of its maximum value. ... Lamp can be: A portable light fixture such as a table lamp or reading lamp (common usage) Lamp (electrical component), a replacable component that produces light, such as: Incandescent light bulb, also known as an incandescent lamp Fluorescent lamp Gas discharge lamp Arc lamp Signal lamp, a device used for... Electromagnetic waves can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. ... â€œUVâ€ redirects here. ... The visible spectrum is the portion of the optical spectrum (light or electromagnetic spectrum) that is visible to the human eye. ...

Description

Fluorescent black lights are typically made in the same fashion as normal fluorescent lights except that only one phosphor is used and the normally clear glass envelope of the bulb may be replaced by a deep-bluish-purple glass called Wood's glass, a nickel-oxide–doped glass, which blocks almost all visible light above 400 nanometers. The color of such lamps is often referred to in the trade as blacklite blue. Fluorescent lamps in Shinbashi, Tokyo, Japan Assorted types of fluorescent lamps. ... 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). ... A black light bulb. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic and silvery with a gold tinge Standard atomic weight 58. ... An oxide is a chemical compound containing an oxygen atom and other elements. ... In semiconductor production, doping refers to the process of intentionally introducing impurities into an intrinsic semiconductor in order to change its electrical properties. ...

The phosphor typically used for a near 368 to 371 nanometer emission peak is either europium-doped strontium fluoroborate (SrB₄O₇F:Eu²⁺) or europium-doped strontium borate (SrB₄O₇:Eu²⁺) while the phosphor used to produce a peak around 350 to 353 nanometers is lead-doped barium silicate (BaSi₂O₅:Pb⁺). Blacklite blue lamps peak at 365 nm. 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 Atomic mass 87. ... Borates in chemistry are chemical compounds containing boron bonded to three oxygen atoms written as B(OR)3. ... For Pb as an abbreviation, see PB. General Name, Symbol, Number lead, Pb, 82 Chemical series Post-transition metals or poor metals Group, Period, Block 14, 6, p Appearance bluish gray Standard atomic weight 207. ... General Name, Symbol, Number barium2, Ba, 56 Chemical series alkaline earth metals Group, Period, Block 2, 6, s Appearance silvery white Standard atomic weight 137. ... In chemistry, a silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by electronegative ligands. ...

A black light may also be formed by simply using Wood's glass instead of clear glass as the envelope for a common incandescent bulb. This was the method used to create the very first black light sources. Though it remains a cheaper alternative to the fluorescent method, it is exceptionally inefficient at producing UV light (a mere few lumens per watt) owing to the black body nature of the incandescent light source. Incandescent UV bulbs, due to their inefficiency, may also become dangerously hot during use. More rarely still, high power (hundreds of watts) mercury vapor black lights can be found which use a UV emitting phosphor and an envelope of Wood's glass. These lamps are used mainly for theatrical and concert displays and also become very hot during normal use. A black light bulb. ... 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). ... As the temperature decreases, the peak of the black body radiation curve moves to lower intensities and longer wavelengths. ... A Mercury Vapor Lamp is a gas discharge lamp which uses mercury in an excited state to produce light. ...

Some UV fluorescent bulbs specifically designed to attract insects for use in bug zappers use the same near-UV emitting phosphor as normal blacklights, but use plain glass instead of the more expensive Wood's glass. Plain glass blocks less of the visible mercury emission spectrum, making them appear light blue to the naked eye. These bulbs are sometimes referred to as "blacklite" or "blacklight blue". A Bug Zapper A bug zapper is a device that attracts and kills insects that are attracted by light. ...

Ultraviolet light can be also generated by some light-emitting diodes. Blue, green and red LEDs. ...

Safety

"Soft" ultraviolet light in the UVA (where most black lights are) may cause wrinkles and skin cancer. Slightly "harder" UVB causes sunburn.^[1] â€œUVâ€ redirects here. ...

Uses

The ultraviolet radiation itself is invisible to the human eye, but illuminating certain materials with UV radiation prompts the visible effects of fluorescence and phosphorescence. Black light testing is commonly used to authenticate antiques and banknotes. It is extensively used in non-destructive testing; fluorescing fluids are applied to metal structures and illuminated with a black light. Cracks and other artifacts can easily be detected. It is also used to detect pet messes for elimination, such as urine, vomit and other substances that are not always visible to the naked eye. Image File history File linksMetadata Download high resolution version (1024x768, 178 KB)A Sanax 15W black light bulb. ... Image File history File linksMetadata Download high resolution version (1024x768, 178 KB)A Sanax 15W black light bulb. ... Image File history File linksMetadata No higher resolution available. ... Image File history File linksMetadata No higher resolution available. ... The euro symbol The euro (EUR or €) is the single currency for many countries within the European Union. ... Image File history File links Download high resolution version (1021x717, 108 KB) Summary Midnight bowling with ultraviolet lights. ... Image File history File links Download high resolution version (1021x717, 108 KB) Summary Midnight bowling with ultraviolet lights. ... A bowler releases the ball. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... Phosphorescent powder under visible light, ultraviolet light, and total darkness. ... ... A Â£20 Bank of England banknote. ... Hot metal work from a blacksmith In chemistry, a metal (Greek: Metallon) is an element that readily loses electrons to form positive ions (cations) and has metallic bonds between metal atoms. ...

It is also used to illuminate pictures painted with fluorescent colors (preferably on black velvet to intensify the illusion of self-illumination). The fluorescence it prompts from certain textile fibers, especially those bearing optical brightener residue, is also used as a recreational effect (as seen for instance in the opening credits of the James Bond film A View to a Kill). Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Velvet is a type of tufted fabric in which the cut threads are very evenly distributed, with a short dense pile, giving it its distinct feel. ... Optical brighteners, optical brightening agents, fluorescent brightening agents or fluorescent whitening agents are dyes that absorb light in the ultraviolet and violet region of the electromagnetic spectrum, and re-emit light in the blue region. ... Flemings image of James Bond; commissioned to aid the Daily Express comic strip artists. ... For the Ian Fleming short story that inspired the film, see From a View to a Kill. ...

In forensic investigations, black lights are used to reveal the presence of trace evidence, such as blood, urine, semen and saliva, by causing visible fluorescence in these substances. The use of this technique by exposé style television news magazines for reporting on the various unsanitary and mysterious stains found in hotel rooms has become such an oft-repeated stunt that it has been lampooned on comedy shows such as Family Guy and The Office (US). The word forensic (from Latin: forensis - forum) refers to something of, pertaining to, or used in a court of law. ... Trace evidence is evidence that is found at a crime scene in small but measurable amounts. ... Human blood smear: a - erythrocytes; b - neutrophil; c - eosinophil; d - lymphocyte. ... This article or section is in need of attention from an expert on the subject. ... Horse semen being collected for breeding purposes. ... Saliva is the watery and usually somewhat frothy substance produced in the mouths of humans and some animals. ... An exposÃ© is an article or book intended to reveal shocking or surprising information. ... A newsmagazine, sometimes called news magazine, is a usually weekly magazine featuring articles on current events. ... Family Guy is an Emmy award winning American animated television series about a nuclear family in the fictional town of Quahog (IPA or ), Rhode Island. ... The Office is an Emmy Award and Peabody Award-winning[1] American television comedy that debuted on NBC as a midseason replacement on March 24, 2005. ...

In Security, a pen with a fluorescent ink, generally a soft tip,is used to 'invisibly' mark items. IF the items are stolen then a black light can be used to search for the security markings.

One of the innovations for night and all-weather flying used by the US, UK and Germany during 1939-1945 was the use of UV floodlights to illuminate the instrument panel, giving a variable intensity alternative to the Radium painted instrument faces and pointers, without visible illumination that would give away an aircraft's position. This went so far as to include the printing of charts that were marked in UV-fluorescent inks, and the provision of UV-visible pencils and slide rules such as the E6B. However, the common failure of the light's power inverter on take-offs in bombers, and the night-blindness and crashes caused when the blacklight filter fell off on trainer aircraft led to the system being mostly abandoned. A couple of very simple pencils A pencil is a handheld instrument used to write and draw, usually on paper. ... The slide rule is a portable, mechanical, analog computer usually consisting of three interlocking calibrated strips and a sliding cursor used to record intermediate results. ... The front of a metal E6B. An E6B flight computer commonly used by student pilots. ...

Black light puppetry is also performed in a black light theatre. Invented by Mitchell Lang of WA Australia, the black light puppet is a form of puppetry. ...

References

New Scientist is a weekly international science magazine covering recent developments in science and technology for a general English-speaking audience. ...

See also

A Woods lamp is a diagnostic tool used in dermatology by which ultraviolet light is shone (at a wavelength of approximately 365 nanometers) onto the skin of the patient; a technician then observes any subsequent fluorescence. ... A Standard Household Light bulb This page is a list of sources of light. ...

External links

Categories: Lighting | Luminescence Image File history File links Commons-logo. ... The Wikimedia Commons (also called Wikicommons) is a repository of free content images, sound and other multimedia files. ... Lighting includes both artificial light sources such as lamps and natural illumination of interiors from daylight. ... A lamp, in technical usage, is a replaceable component such as an incandescent light bulb, which is designed to produce light from electricity. ... An incandescent lamp bulb and its glowing filament. ... An incandescent lamp bulb and its glowing filament. ... 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. ... Image File history File links Download high resolution version (311x649, 278 KB) Summary I made this from an existing Public Domain JPEG. Licensing File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... A spiral type compact fluorescent lamp. ... Fluorescent lamps in Shinbashi, Tokyo, Japan Assorted types of fluorescent lamps. ... 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, low-pressure sodium 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. ... Metal halide lamps, a member of the high-intensity discharge (HID) family of lamps, produce high light output for their size, making them a compact, powerful, and efficient light source. ... 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. ... A LPS / SOX streetlight at full power A sodium vapor lamp is a gas discharge lamp which uses sodium in an excited state to produce light. ... 15 kW Xenon short-arc lamp. ... An HMI on a stand. ... 15 kW Xenon short-arc lamp used in IMAX projectors Xenon arc lamps are an artificial light source. ... A Yablochkov candle (sometimes electric candle) is a type of electric carbon arc lamp, invented in 1876 by Pavel Yablochkov. ... Lit carbide lamp Carbide lamp on a bicycle Carbide lamps (acetylene lamps) are simple lamps that produce and burn acetylene (C2H2) gas produced by reacting calcium carbide (CaC2) with water. ... A close-up image of a candle showing the wick and the various regions of the flame. ... Gas lighting is the process of burning piped natural gas or coal gas for illumination. ... It has been suggested that Petromax be merged into this article or section. ... Limelight is a type of stage lighting once used in theatres and music halls. ... Antique bronze oil lamp with Christian symbol (replica) An oil lamp is a device used for lighting or for preserving a flame that is fueled by animal, vegetable or mineral oil. ... 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. ... It has been suggested that this article or section be merged into Kerosene lamp. ... LBNL researcher examines prototype sulfur lamp. ... Blue, green and red LEDs. ... LED Lamp with bayonet mount LED Lamp with E27 Edison screw. ... 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. ... Optical fibers An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length by confining as much light as possible in a propagating form. ... 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. ...

Contents

Description GA_googleFillSlot("encyclopedia_square");