black lights (or often black light ), also referred to as lights UV-A , wooden lights , or just ultraviolet light , are lights that emit ultraviolet rays of long waves (UV-A) and not much visible light.
One type of lamp has a purple filter material, either on a bulb or in a separate glass filter in the lamp house, which blocks the most visible and possible light through the UV, so the lamp has a dimly lit purple light when operating. Blacklight lights that have this filter have a lighting industry designation that includes the letter "BLB". It stands for "blacklight blue", which is a contradiction because they are the type that does not look blue.
The second type of lamp produces ultraviolet but does not have a filter material, resulting in more visible light and has a blue color during operation. This tube is made for use in the "bug zapper" bug trap, and is identified by the industry designation "BL".
Blacklight sources can be specially designed fluorescent lamps, mercury vapor lamps, light-emitting diodes (LEDs), lasers, or incandescent lamps; although incandescent lights produce almost no black light (except a little more for the type of halogens), and therefore are not considered to be the true sources of black light. In medicine, forensics, and other scientific fields, such light sources are referred to as Wood's lamps, named after Robert Williams Wood who invented the original wooden glass UV filters.
Although many other types of lights emit ultraviolet light with visible light, black lights are essential when UV-A lightless light appears to be necessary, especially in observing fluorescence, the colored light that many substances emit when exposed to UV. Black lights are used for decorative and artistic lighting effects, diagnostic and therapeutic use in the medical world, the detection of substances characterized by fluorescent dye, rock hunting, counterfeit detection, drying of plastic resins, attracting insects and detecting leakage substances affecting the refrigerator and air conditioning system. A strong long-wave ultraviolet light source is used in tanning beds. Although low-power UV-A emitted by black lights is not harmful to the skin or eyes and can be seen without protection, powerful ultraviolet sources present hazards and require personal protective equipment such as goggles and gloves.
Video Blacklight
Jenis
Fluorescent
The fluorescent black fluorescent tube is usually made in the same way as a normal fluorescent tube except that the phosphorus emits UVA rays rather than the visible white light used. The most commonly used type for black lights, designated industrial blue "BLB black light" or "BLB", has a dark blue filter layer on the tube, which filters out most of the visible light, so the fluorescence effect can be observed. These tubes have a dimly lit purple light when operating. They should not be confused with "black" or "BL" tubes, which do not have a filter layer, and have a bright blue color. It's made for use in the "bug zapper" bug trap, where visible light emissions are not a problem. The phosphorus normally used to approach 368 to 371 nanometers of emission peaks is europium-doped strontium fluoroborate ( SrB
4 O
7 F : Eu 2
) or europium-doped strontium borate ( SrB
4 O
7 : < span> Eu 2 ) while the phosphor used for producing a peak of about 350 to 353 nanometers is a doped barium silicate ( BaSi
2 O
5 : Pb
) The" Blacklight Blue "light culminates in 365Ã, nm.
Manufacturers use different numbering systems for black light tubes. Philips uses an outdated system (2010), while the Osram (German) system becomes dominant outside North America. The following table lists tubes that produce blue, UVA and UVB colors, in order to reduce the wavelength from the most intense peaks. Estimates of phosphor compositions, major manufacturer type numbers and several uses are given as an overview of the available types. The "Peak" position is approximated nearest 10 nm. "Width" is the measure between the point on the peak shoulder representing the intensity of 50%.
The wooden glass tube produced by Osram uses phosphors that emit narrow bands, europium preparatory active strontium with peaks at about 370Ã, nm, while North American glass tubes and Philips Wood use a lead activated calcium metasilicate that emits wider bands of length shorter waves. its peak is about 350Ã, nm. Both of these types seem to be most commonly used. Different manufacturers offer one or the other and sometimes both.
The BLB fluorescent lamps tend to run with efficiency in the 25% range, with example being a Phillips 40W BLB T12 lamp that emits 9.8W UVA for 39 Watt of input power. Tube
"Bug zapper"
Another class of UV fluorescent lamps are designed for use in the flying bug trap "bug zapper". Insects are attracted to UV light, which they can see, and then electrocuted by the device. These tubers use the same UV-A phosphor mix as filtered black light, but since they do not have to suppress the visible light output, they do not use purple filter material on the bulb. Plain glass blocks less than the visible spectrum of mercury emissions, making it look purple-blue to the naked eye. These lights are called "blacklight" or "BL" in some North American lighting catalogs. These types are not suitable for applications requiring low visible light output from "BLB" tube lights.
Incandescent
Black lights can also be formed using only UV filter layers such as Wood glass on envelopes of common incandescent bulbs. This is the method used to create the first black light source. Although black incandescent light bulbs are a cheaper alternative to fluorescent tubes, they are very inefficient in generating UV light because most of the light emitted by filaments is visible light that must be blocked. Because of its black body spectrum, incandescent light emits less than 0.1% of its energy as UV rays. The incandescent UV lamp, due to the required absorption of visible light, becomes extremely hot during use. This heat, in fact, is driven in such lights, since the hotter filaments increase the proportion of UVA in the radiation of the emitted black object. This high running temperature drastically reduces lamp life, however, from about 1000 hours to about 100 hours.
Mercury vapor
High power mercury black steam lamps are made in power ratings of 100 to 1000 watts. It does not use phosphorus, but relies on a more intensive and slightly expanded mercury spectrum line from high pressure pressure between 5 and 10 standard atmospheres (500 and 1,000 kPa), depending on the specific type. These lamps use Wood glass envelopes or similar optical filter layers to block all visible light and short mercury wavelength (UVC) lines at 184.4 and 253.7 nm, which are harmful to the eyes and skin. Several other spectral lines, falling within the tape graduated from Wood glasses between 300 and 400nm, contributed to the output. These lights are used primarily for theatrical purposes and concert performances. They are more efficient UVA manufacturers per unit of power consumption than fluorescent tubes.
LED
Ultraviolet light can be generated by several light-emitting diodes, but wavelengths below 380 nm are not common and emission peaks are widespread, so only the lowest-energy UV photons emitted, in a highly visible light.
Maps Blacklight
Medical applications
A Wooden lamp is a diagnostic tool used in dermatology in which ultraviolet light shines (at a wavelength of about 365 nanometers) to the patient's skin; a technician then observes the next fluorescence. For example, porphyrin - associated with some skin diseases - will be pink. Although the technique for producing ultraviolet light sources was made by Robert Williams Wood in 1903 using "Wood glass", in 1925 the technique was used in dermatology by Margarot and Deveze to detect fungal infections in hair. It has many uses, both in distinguishing the fluorescent conditions from other conditions and in finding the exact limits of the condition.
Fungal and bacterial infections
It also helps in diagnosing:
- Fungal infections. Some tinea forms, such as Trichophyton tonsurans , do not fluoresce.
- Bory
- Corynebacterium minutissimum coral infections
- Pseudomonas greenish yellow
- Propionibacterium acnes , a bacterium involved in the cause of acne, shows an orange light under Wood's lamp.
Ethylene glycol poisoning
Wood lamps can be used to quickly assess whether a person is suffering from ethylene glycol poisoning as a consequence of antifreeze consumption. An antifreef producer containing ethylene glycol generally adds fluorescein, which causes the patient's urine to glow under Wood's lamp.
More
Wooden lamps are useful in diagnosing conditions such as tuberous sclerosis and erythrasma (caused by ' Corynebacterium minutissimum' , see above). In addition, detection of cutaneous porphyria tarda can sometimes be performed when the urine turns pink when illuminated with a Wood lamp. Wood lamps have also been used to distinguish hypopigmentation from depigmentation as with vitiligo. The skin of vitiligo patients will appear yellow-green or blue under Wood's lamp. Its use in detecting melanoma has been reported.
See also
Light Bili. This type of phototheraphy that uses blue light with a range of 420-470 nm, is used to treat neonatal jaundice.
Security
Although black lights produce light in the UV range, their spectra are largely confined to the long-wave UVA region, which is the nearest UV radiation in visible light wavelengths, with low frequencies and relatively low energy. While low, there is still some conventional black light power in the UVB range. UVA is the safest of the three UV light spectra, although high exposure to UVA has been associated with the development of skin cancer in humans. The relatively low energy of UVA light does not cause sunburn. UVA is capable of causing damage to collagen fibers, however, so it has the potential to accelerate skin aging and lead to wrinkles. UVA can also destroy vitamin A in the skin.
UVA rays have been shown to cause DNA damage, but not directly, like UVB and UVC. Because of the longer wavelengths, it is absorbed less and reaches deeper into the skin layer, where it produces reactive chemical intermediates such as hydroxyl and oxygen radicals, which in turn can damage DNA and lead to the risk of melanoma. Weak output from black lights, however, is not considered sufficient to cause DNA damage or cellular mutations in a way that can direct summer sunlight, although there are reports that overexposure to the type of UV radiation used to create artificial sunbathing on sunbeds can cause DNA damage, photoaging (skin damage due to prolonged exposure to sunlight), skin toughness, suppression of the immune system, cataract formation and skin cancer.
Usage
Ultraviolet radiation is not visible to the human eye, but illuminating certain matter with UV radiation causes visible light emission, causing this substance to glow with a variety of colors. This is called fluorescence , and has many practical uses. Black lights are needed to observe fluorescence, as other types of ultraviolet lights emit visible light that sinks dim fluorescent light.
Black light is commonly used to authenticate oil paintings, antiques and paper money. Black lights can be used to distinguish the original currency from fake notes because, in many countries, legal banknotes have fluorescence symbols on those that are only displayed under black light. In addition, the paper used to print money does not contain any brightening ingredients that cause commercially available paper to glow under black light. Both of these features make illegal records more easily detected and more difficult to successfully forge. The same security feature can be applied to the identification card.
Other security applications include the use of a pen containing fluorescent inks, generally with a soft tip, which can be used to mark "invisible" items. If the objects are so marked then stolen, black light can be used to look for this security mark. In some theme parks, nightclubs and other events, throughout the day (or night-long), the neon sign is a rubber stamp to the guest wrist which can then use the option to go and can come back again without paying any more money.
In treatment, Wood's lamps are used to examine the characteristics of certain dermatophyte fungal fluorescence such as the Microsporum species emitting yellow light, or corynebacterium that has a red to orange color when viewed under Wood's lamp. Such light is also used to detect the presence and degree of disturbance that leads to loss of pigmentation, such as vitiligo. It can also be used to diagnose other fungal infections such as ringworm, canis microsporum, tinea versicolor; bacterial infections such as erythrasma; Other skin conditions include acne, scabies, alopecia, porphyria; as well as corneal scratches, foreign objects in the eye, and clogged tears.
Fluorescent materials are also widely used in various applications in molecular biology, often as "tags" that bind themselves to interesting substances (eg, DNA), thus allowing their visualization. Black rays can also be used to view animal waste such as urine and vomit that is not always visible to the naked eye.
Black light is used extensively in non-destructive testing. Fluorescing fluids are applied to metal structures and illuminated with black light allowing cracks and other weaknesses in material to be easily detected. It is also used to illuminate images painted with fluorescent colors, especially on black velvet, which intensifies the illusion of illumination. The use of such materials, often in the form of tiles viewed in the sensory space under UV light, is common in the UK for the education of students with deep and numerous learning difficulties. Such fluorescence of certain textile fibers, especially those containing optical lightening residues, can also be used for recreational effects, as seen, for example, in James Bond film opening credits A View to a Kill. Black light puppetry is also performed in a black light theater.
One of the innovations for the night and all the flying weather used by the US, UK, Japan and Germany during World War II was the use of UV interior lighting to illuminate the instrument panel, providing a safer alternative to radium-painted face and pointers, and the intensity that can vary easily and without visible lighting that will give the plane a position. This further includes to include charts marked with UV-fluorescent inks, and the provision of UV-visible pencils and slide rules such as E6B.
Thousands of moths and insect collectors around the world use different types of black lights to attract moths and insect specimens for photography and collection. This is one of the preferred light sources for attracting insects and moths at night.
It can also be used to test LSD, which fluoresces under black light while common replacements like 25I-NBOMe are not.
In addition, if leaks are suspected in refrigerators or air conditioning systems, UV-tracking dyes can be injected into the system along with compressor lubricating oil and refrigerant mixtures. The system is then run to circulate the dye across the piping and components and then the system is checked with a blacklight lamp. Each proof of fluorescent dye then determines the leaking part that needs to be replaced.
See also
- Blacklight poster
- List of light sources
References
External links
- MedlinePlus Encyclopedia Wood lamp check
- "U.V.C to U.V.A Conversion of Phosphor for Black Light source". Sylvania. Archived from the original on 2011-07-24.
- "What material is Glow Under a Black or Ultraviolet Light?". About.com.
- "Mineral database fluoresces with images, activators, and spectra". fluomin.org.
- http://mississippientomologicalmuseum.org.msstate.edu/collecting.preparation.methods/Blacklight.traps.htm#.VjLiNdKrQwA
Source of the article : Wikipedia
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