Spectrum of a black light fluorescent tube.FWHMspectral bandwidth of the 370nm peak is about 20nm. The tiny secondary peak
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Fluorescent body paint. Paints and decorations that fluoresce under black light are used in theater and several art forms.
Although black lights produce light in the UV range, their spectrum is mostly confined to the longwave UVA region, that is, UV radiation nearest in wavelength to visible light, with low frequency and therefore relatively low energy. While low, there is still some power of a conventional black light in the UVB range.UVA is thesafest of the three spectra of UV light, although high exposure to UVA has been linked to the development ofskin cancerin humans. The relatively low energy of UVA light does not causesunburn. UVA is capable of causing damage tocollagenfibers, however, so it does have the potential to accelerateskinaging and causewrinkles. UVA can also destroyvitamin Ain the skin.
Thousands of moth and insect collectors all over the world use various types of black lights to attract moth and insect specimens for photography and collecting. It is one of the preferred light sources for attracting insects and moths at night.
The Right Light: Matching Technologies to Needs and Applications
. John Wiley and Sons. pp.5.ISBN978-1-4051-6169-5Archivedfrom the original on 27 May 2013
Black light fluorescent tubes. The violet glow of a black light is not the UV light itself, but visible light that escapes being filtered out by the filter material in the glass envelope.
This page was last edited on 26 April 2018, at 06:13.
2015-12-25 at theWayback Machine. A fluorometer was designed to detect very small amounts of LSD and ergonovine. The instrument proved less satisfactory than the Bowman fluorometer. Both LSD and ergonovine lost their fluorescence very rapidly upon strong ultraviolet irradiation. The mechanism involved in this decrease in fluorescence is not known.
Anti-counterfeiting design of aChinese passportglows under black light.
What Materials Glow Under a Black or Ultraviolet Light?. .
Paraskevas L. R., Halpern A. C., Marghoob A. A. (2005). Utility of the Woods light: five cases from a pigmented lesion clinic.
. Glow Inc. 2010. Archived fromthe originalon June 29, 2013
Prevost E. (October 1983). The rise and fall of fluorescent tinea capitis.
One type of lamp has a violetfiltermaterial, either on the bulb or in a separate glass filter in the lamp housing, which blocks most visible light and allows through UV,so the lamp has a dim violet glow when operating.Blacklight lamps which have this filter have a lighting industry designation that includes the letters BLB.This stands for blacklight blue, which is a contradiction in that they are the type that doesnotlook blue.
In addition, if a leak is suspected in arefrigeratoror anair conditioningsystem, a UV tracer dye can be injected into the system along with the compressor lubricant oil and refrigerant mixture. The system is then run in order to circulate the dye across the piping and components and then the system is examined with a blacklight lamp. Any evidence of fluorescent dye then pinpoints the leaking part which needs replacement.
. Taylor & Francis. p.125.ISBN0240515668Archivedfrom the original on 2013-05-27.
Ablacklight(or oftenblack light), also referred to as aUV-A light,Woods lamp, or simplyultraviolet light, is alampthat emits long-wave (UV-Aultraviolet lightand not muchvisible light.
(6th ed.). Elsevier. p.202.ISBN143775581XArchivedfrom the original on 2013-05-26.
AWoods lampis a diagnostic tool used indermatologyby whichultraviolet lightis shone (at a wavelength of approximately 365 nanometers) onto the skin of the patient; a technician then observes any subsequentfluorescence. For example,porphyrinsassociated with some skin diseaseswill fluoresce pink. Though the technique for producing a source of ultraviolet light was devised byRobert Williams Woodin 1903 usingWoods glass, it was in 1925 that the technique was used indermatologyby Margarot and Deveze for the detection of fungal infection of hair. It has many uses, both in distinguishing fluorescent conditions from other conditions and in locating the precise boundaries of the condition.
Gupta, I. K.; Singhi, M. K. (2004).Woods Lamp.
Compiled from various Philips, Osram and Sylvania Lighting Catalogues
It may also be used to test forLSD, which fluoresces under black light while common substitutes such as25I-NBOMedo not.
Black light is used extensively in non-destructive testing. Fluorescing fluids are applied tometalstructures and illuminated with a black light which allows cracks and other weaknesses in the material to be easily detected. It is also used to illuminate pictures painted with fluorescent colors, particularly on blackvelvet, which intensifies the illusion of self-illumination. The use of such materials, often in the form of tiles viewed in asensory roomunder UV light, is common in the United Kingdom for the education of students with profound and multiple learning difficulties.Such fluorescence from certain textile fibers, especially those bearingoptical brightenerresidues, can also be used for recreational effect, as seen, for example, in the opening credits of theJames BondfilmA View to a Kill.Black light puppetryis also performed in a black light theater.
) or europium-doped strontium borate (SrB
2010-06-05 at theWayback Machine. Equipment for use in sensory rooms for students with profound and multiple learning difficulties in United Kingdom schools.
under ultraviolet from a black light
Morales-Trujillo M. L., Arenas R., Arroyo S. (July 2008).[Interdigital erythrasma: clinical, epidemiologic, and microbiologic findings].
Winter M. L., Ellis M. D., Snodgrass W. R. (June 1990).Urine fluorescence using a Woods lamp to detect the antifreeze additive sodium fluorescein: a qualitative adjunctive test in suspected ethylene glycol ingestions.
, a bacterium involved inacnecausation, exhibits an orange glow under a Woods lamp.
Ultraviolet radiation is invisible to the human eye, but illuminating certain materials with UV radiation causes the emission of visible light, causing these substances to glow with various colors. This is calledfluorescence, and has many practical uses. Black lights are required to observe fluorescence, since other types of ultraviolet lamps emit visible light which drowns out the dim fluorescent glow.
. 1000Bulbs.com.Archivedfrom the original on February 14, 2013
Cole, Curtis; Forbes, P. Donald; Davies, Ronald E. (1986).An Action Spectrum for UV Photocacinogenesis.
) while the phosphor used to produce a peak around 350 to 353 nanometres is lead-doped barium silicate (BaSi
U.V.C to U.V.A conversion Phosphors for Black Light sources. Sylvania. Archived fromthe originalon 2011-07-24.
Blacklight sources may be specially designedfluorescent lampsmercury-vapor lampslight-emitting diodes(LEDs),lasers, orincandescent lamps; although incandescents produce almost no blacklight (except slightly more for halogen types), and so are not considered true blacklight sources.Inmedicineforensics, and some other scientific fields, such a light source is referred to as a Woods lamp, named afterRobert Williams Woodwho invented the originalWoods glassUV filters.
BLB fluorescent lamps tend to run with efficiencies in the 25% range, with an example being a Phillips 40W BLB T12 lamp emitting 9.8W of UVA for 39 Watts of power input.
UVA light has been shown to causeDNA damage, but not directly, like UVB and UVC. Due to its longerwavelength, it is absorbed less and reaches deeper intoskin layers, where it produces reactive chemical intermediates such ashydroxyland, which in turn can damage DNA and result in a risk ofmelanoma. The weak output of black lights, however, is not considered sufficient to cause DNA damage or cellularmutationsin the way that direct summer sunlight can, although there are reports that overexposure to the type of UV radiation used for creating artificial suntans onsunbedscan cause DNA damage, photoaging (damage to the skin from prolonged exposure to sunlight), toughening of the skin, suppression of the immune system, cataract formation and skin cancer.
is light from the mercury vapor line at 404nm leaking through the filter, which gives the lamp its purple glow.
Miller, Larry S.; McEvoy Jr., Richard T. (2010).
(2): 1315.PMID17642589Archivedfrom the original on 2011-09-29.
Two black light fluorescent tubes, showing use. The top is a F15T8/BLB 18 inch, 15 watt tube, used in a standard plug-in fluorescent fixture. The bottom is an F8T5/BLB 12 inch, 8 watt tube, used in a portable battery-powered black light sold as a pet urine detector.
). Blacklight Blue lamps peak at 365nm.
Lighting Control: Technology and Applications
Tony Burns; Stephen Breathnach; Neil Cox; Christopher Griffiths (2010).
Database of fluorescent minerals with pictures, activators and spectra. fluomin.org.
Bili light. A type of phototheraphy that uses blue light with a range of 420-470 nm, used to treatneonatal jaundice.
Hemady, N.; Noble, C. (2007).Photo Quiz An infant with a hypopigmented macule.
Ultraviolet light can be generated by somelight-emitting diodes, but wavelengths below 380nm are uncommon and the emission peaks are broad, so only the very lowest energy UVphotonsare emitted, within predominantly visible light.
Fungal infections. Some forms oftinea, such as
Woods glass tubes manufactured by Osram use a fairly narrow-band emitting phosphor, europium activated strontium pyroborate with a peak at about 370nm, whereas North American and Philips Woods glass tubes use lead-activated calcium metasilicate that emits a wider band with a shorter wavelength peak at about 350nm. These two types seem to be the most commonly used. Different manufacturers offer either one or the other and sometimes both.
CS1 maint: Uses authors parameter (link)
For other uses, seeBlack Light (disambiguation).
Operations/surgeriesand other procedures of theskinandsubcutaneous tissueICD-9-CM V386,ICD-10-PCS 0H)
(7): 10534.PMID17427621Archivedfrom the original on 2008-08-28.
CS1 maint: Uses authors parameter (link)
High powermercury vaporblack light lamps are made in power ratings of 100 to 1000 watts. These do not use phosphors, but rely on the intensified and slightly broadened 350375nm spectral line of mercury from high pressure discharge at between 5 and 10 standard atmospheres (500 and 1,000kPa), depending upon the specific type. These lamps use envelopes of Woods glass or similar optical filter coatings to block out all the visible light and also the short wavelength (UVC) lines of mercury at 184.4 and 253.7nm, which are harmful to the eyes and skin. A few other spectral lines, falling within the pass band of the Woods glass between 300 and 400nm, contribute to the output. These lamps are used mainly for theatrical purposes and concert displays. They are more efficient UVA producers per unit of power consumption than fluorescent tubes.
. CRC Press. p.108.ISBN1439899312Archivedfrom the original on 2013-05-27.
Woods lamp is useful in diagnosing conditions such astuberous sclerosisanderythrasma(caused byCorynebacterium minutissimum, see above).Additionally, detection ofporphyria cutanea tardacan sometimes be made when urine turns pink upon illumination with Woods lamp.Woods lamps have also been used to differentiate hypopigmentation from depigmentation such as withvitiligo. A vitiligo patients skin will appear yellow-green or blue under the Woods lamp.Its use in detectingmelanomahas been reported.
A second type of lamp produces ultraviolet but does not have the filter material, so it produces more visible light and has a blue color when operating.These tubes are made for use inbug zapperinsect traps, and are identified by the industry designation BL.
ESPCR Blog. European Society for Pigment Cell Research.Archivedfrom the original on 2011-07-26.
Thesecurity threadof aUS $20 billglows green under black light as a safeguard againstcounterfeiting.
Mike Phillips (2007-09-25).Eikone.com. Eikone.com.Archivedfrom the original on 2012-03-06
Rorie, Benjamin (2011).How Do Black Lights Work?.
One of the innovations for night and all-weather flying used by the US, UK, Japan andGermanyduringWorld War IIwas the use of UV interior lighting to illuminate the instrument panel, giving a safer alternative to theradium-painted instrument faces and pointers, and an intensity that could be varied easily and without visible illumination that would give away an aircrafts position. This went so far as to include the printing of charts that were marked in UV-fluorescent inks, and the provision of UV-visiblepencilsandslide rulessuch as theE6B.
A Woods lamp may be used to rapidly assess whether an individual is suffering fromethylene glycol poisoningas a consequence ofantifreezeingestion. Manufacturers of ethylene glycol-containing antifreezes commonly addfluorescein, which causes the patients urine tofluoresceunder Woods lamp.
From Wikipedia, the free encyclopedia
Although many other types of lamp emit ultraviolet light with visible light, black lights are essential when UV-A light without visible light is needed, particularly in observingfluorescence,the colored glow that many substances emit when exposed to UV. Black lights are employed for decorative and artistic lighting effects, diagnostic and therapeutic uses in medicine,the detection of substances tagged withfluorescent dyesrock-hunting, the detection ofcounterfeit money, the curing of plastic resins, attracting insectsand the detection ofrefrigerantleaks affectingrefrigeratorsandair conditioningsystems. Strong sources of long-wave ultraviolet light are used intanning beds.Although the low-power UV-A emitted by black lights is not a hazard to skin or eyes and can be viewed without protection, powerful ultraviolet sources present dangers and requirepersonal protective equipmentsuch as goggles and gloves.
Other security applications include the use of pens containing a fluorescent ink, generally with a soft tip, that can be used to invisibly mark items. If the objects that are so marked are subsequently stolen, a black light can be used to search for these security markings. At sometheme parksnightclubsand at other, day-long (or night-long) events, a fluorescent mark isrubber stampedonto the wrist of a guest who can then exercise the option of leaving and being able to return again without paying another admission fee.
Another class of UV fluorescent bulb is designed for use inbug zapperflying insect traps. Insects are attracted to the UV light, which they are able to see, and are thenelectrocutedby the device. These bulbs use the same UV-A emitting phosphor blend as the filtered blacklight, but since they do not need to suppress visible light output, they do not use a purple filter material in the bulb. Plain glass blocks out less of the visible mercury emission spectrum, making them appear light blue-violet to the naked eye. These lamps are referred to by the designation blacklight or BL in some North American lighting catalogs. These types are not suitable for applications which require the low visible light output of BLB tubeslamps.
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Fluoresceinglowing under ultraviolet light
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Zaithanzauva Pachuau; Ramesh Chandra Tiwari (OctoberDecember 2008).Ultraviolet Light- its Effects and Applications
Black light is commonly used to authenticateoil paintingsantiquesandbanknotes. Black lights can be used to differentiate real currency fromcounterfeitnotes because, in many countries, legal banknotes have fluorescent symbols on them that only show under a black light. In addition, the paper used for printing money does not contain any of the brightening agents which cause commercially available papers to fluoresce under black light. Both of these features make illegal notes easier to detect and more difficult to successfully counterfeit. The same security features can be applied to identification cards.
Fluorescent black light tubes are typically made in the same fashion as normalfluorescent tubesexcept that aphosphorthat emits UVA light instead of visible white light is used. The type most commonly used for black lights, designatedblacklight blueor BLB by the industry, has a dark blue filter coating on the tube, which filters out most visible light, so thatfluorescenceeffects can be observed. These tubes have a dim violet glow when operating. They should not be confused with blacklight or BL tubes, which have no filter coating, and have a brighter blue color.These are made for use inbug zapperinsect traps, where visible light emission is not a problem. The phosphor typically used for a near 368 to 371 nanometer emission peak is eithereuropium-doped strontium fluoroborate (SrB
(6): 6637.doi10.1016/S0196-0644(05)82472-2PMID2344083Archivedfrom the original on 2017-12-21.
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Zeman, Gary (2009).Ultraviolet Radiation. Health Physics Society.Archivedfrom the original on 2010-01-13.
. Academic Press. p.642.ISBN0080860303Archivedfrom the original on 2013-05-27.
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Fluorescent materials are also very widely used in numerous applications in molecular biology, often as tags which bind themselves to a substance of interest (for example, DNA), so allowing their visualization. Black light can also be used to see animal excreta such as urine and vomit that is not always visible to the naked eye.
In medicine, the Woods lamp is used to check for the characteristic fluorescence of certaindermatophyticfungi such as species ofMicrosporumwhich emit a yellow glow, orcorynebacteriumwhich have a red to orange color when viewed under a Woods lamp. Such light is also used to detect the presence and extent of disorders that cause a loss of pigmentation, such asvitiligo. It can also be used to diagnose otherfungal infectionssuch asringwormmicrosporum canistinea versicolor; bacterial infections sucherythrasma; other skin conditions includingacnescabiesalopeciaporphyria; as well ascornealscratches, foreign bodies in the eye, and blocked tear ducts.
Manufacturers use different numbering systems for black light tubes. Philips uses one system which is becoming outdated (2010), while the (German)Osramsystem is becoming dominant outside North America. The following table lists the tubes generating blue, UVA and UVB, in order of decreasing wavelength of the most intense peak.Approximate phosphor compositions, major manufacturers type numbers and some uses are given as an overview of the types available. Peak position is approximated to the nearest 10nm. Width is the measure between points on the shoulders of the peak that represent 50% intensity.
Phillips Lighting E-Catalog. philips.com. 2011
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A collection of minerals fluorescing under a black light
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A black light may also be formed by simply using a UV filter coating such asWoods glasson the envelope of a commonincandescent bulb. This was the method that was used to create the very first black light sources. Although incandescent black light bulbs are a cheaper alternative to fluorescent tubes, they are exceptionally inefficient at producing UV light since most of the light emitted by the filament is visible light which must be blocked. Due to itsblack bodyspectrum, an incandescent light radiates less than 0.1% of its energy as UV light. Incandescent UV bulbs, due to the necessary absorption of the visible light, become very hot during use. This heat is, in fact, encouraged in such bulbs, since a hotter filament increases the proportion of UVA in the black-body radiation emitted. This high running-temperature drastically reduces the life of the lamp, however, from a typical 1000 hours to around 100 hours.
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