When heated up the metal would vaporize and the lamp would glow yellow. This test is used to determine if an item can be managed as hazardous. In these lamps, a material, such as sodium, mercury, or metal halide, is added to the arc tube. One would tip the lamp, and electrical contacts on each side of the lamp would send electricity through a liquid mercury which started the lamp. The first mercury vapor lamps were in a lower pressure tube. The solid sodium metal remained on the bottom center of the bulb. They differ primarily by electrical excitation and ionization levels of the mercury within the lamp and corresponding internal pressures. A low pressure mercury vapor discharge lamp having a suitable combination of a main amalgam and an auxiliary amalgam. Mercury vapor lamps benefits, health hazards and pollution. They differ only in the source of mercury vapor mercury lamps use a small amount of liquid metallic mercury, while amalgam lamps. Nov 14, 20 mercury vapor lamps have found the greatest use in industrial applications and outdoor lighting, because of their low cost and long life, and lamp sizes of up to 1,000 watts. An electric current in the gas energizes mercury vapor which delivers ultraviolet radiation through discharge process and the ultraviolet radiation causes the phosphor coating of the lamp inner wall to radiate visible light. A fluorescent lamp, or fluorescent tube, is a lowpressure mercuryvapor gasdischarge lamp that uses fluorescence to produce visible light. In gas discharge lamps, light is generated primarily by an electrically excited plasma.
For the 14 most prominent lines the absolute irradiances should be useful for radiometric calibration at an uncertainty level of 15% 95% confidence. A sodiumvapor lamp is a gasdischarge lamp that uses sodium in an excited state to produce light at a characteristic wavelength near 589 nm two varieties of such lamps exist. The low pressure uv lamps, also called germicidal lamps, exploit uvc light to get the rapid sterilization of bacteria, molds, fungi, viruses and microorganisms both in air and in water. Even though more cleaning may be required for medium and amalgam lamp based systems, due to the reduced number of. These lamps are clear and are commonly called germicidal lamps. One would tip the lamp, and electrical contacts on each side of the lamp would send electricity through a. Ultraviolet lamps ultraviolet heating helios quartz. Helios usually chooses quartz glass for the production of low pressure uv lamps because it ensures very high levels of uv transmission equal to or higher than 90%. The snow white is a low pressure mercury discharge lamp with a tubular 26 mm envelope, available in 18 w, 36 w and 58 w. A sodium vapor lamp is a lamp that uses sodium to create light.
The clear mercury bulb has a bluish green appearance and the deluxe white has a higher color rendering. Medium pressure lamps produce the greatest uv output per unit length of lamp, of the three lamp types. Mercury vapor lamps consist of an inner arc discharge tube constructed of quartz surrounded by an outer hard borosilicate glass envelope. All high pressure sodium lamps contain some amount of mercury. A common discharge lighting luminary for use in an office environment would typically be a lowpressure mercury vapour electronic discharge fluorescent lamp. To facilitate starting of the lamp, a third electrode is mounted near one of the main electrodes and connected through a resistor to the other main electrode. Low pressure sodium lamps were invented first in 1920 by arthur h. A low pressure mercury lamp lp hg lamp is a highly efficient uv light source of short wavelength. The first practical mercury lamp was the cooperhewitt lamp developed by peter cooper hewitt in 1901. It has the older 84 colour code that after about mid nineties became 840. This gives a typical diffuse mediumpressure uv spectrum see figure 3.
All highintensitydischarge lamps produce light from an arc tube that is usually contained in an outer glass bulb. The average life of tube lights is about 5000 hours and also they are very cheap, hence they are very popular. Since the light emitted by a mercury vapor light has a blue tone, this needs to be accounted for, or color corrected as it is called. Hach replacement uv for toc analyzers, arc imaging, chromatography, photochemistry, calibration of uv detectors, calibrations of spectrophotometer, and more. A low pressure mercury lamp is one of the most popular discharge lamps in labs, frequently used for wavelength calibration of optical measuring instruments and as a disinfection lamp to sterilize workspace and tools used in biology labs and medical facilities. In lowpressure mercury vapor lamps, only the lines at 184 and 253 nanometers nm are present. When used with the heraeus c430 power supply, the line output is much higher than and the stability comparable to that of a deuterium lamp. Typical applications include street lighting, parking lot lighting, building floodlighting and general area lighting. The phosphor coating on the inside of the glass tube absorbs uv photons and reradiates the energy as visible light. The lamps are recyclable unless the lamp is broken. Heraeus noblelight offers a broad range of germicidal uv lamps that are manufactured from high quality quartz glass. High efficiency and good color rendition make this type of traditional.
This was a tubular source about 4 feet long which produced light that was distinctly bluishgreen in color at a high efficacy compared with the incandescent lamps of those days. Low pressure mercury fluorescent lamps or tube lights. Germicidal uv lamps standard low pressure lamps from heraeus noblelight with highenergy uv light contaminated water, air and surfaces can be disinfected and cleaned safely. Designed by experienced engineers, and by using quality material in combination with a tightly controlled manufacturing process, we provide high quality lamps free of impurities to maintain strong and stable output throughout life of the lamp. In order for one manufacturers fluorescent lamp to. Recycling used mercurycontaining lamps fluorescent lamps tubes and compacts contain low pressure mercury vapor gas. Low pressure mercury fluorescent lamps are commonly called tube lights. Rather than a cold spot, the lamp s amalgam spot on pellet regulates mercury vapor pressure during operation and yields up to three times the uvc output of a standard low pressure mercury lamp of the same length. Lowpressure mercury vapor discharge lamp having a closed elongated lamp envelope and comprising at least two electrodes disposed near a first end of the lamp envelope, at least one electrode is situated at the end of at least one inner tube situated within and sealed in a gastight manner to the lamp envelope, this inner tube having at least one opening to the inside of the lamp envelope, the. Engineering high intensity discharge bulletin mercury lamps. Voltage runs to the light through a ballast, which regulates the current. The discharge tube may be linear sli lamp 2 or ushaped.
Oct 14, 2014 high pressure mercury lamps are available in versions where the discharge takes place in vaporized mercury only and in versions in which metal halides are added so that the discharge takes place in mercury vapor and in vaporized metals from the metalhalide components 2, 3. Fluorescent lamp and working principle of fluorescent lamp. The inner surface of the lamp is coated with a fluorescent and often slightly phosphorescent coating made of varying blends of metallic and rareearth. Fluorescent lamps3 operate at a very low gas pressure. However, the japanese specifications supercede the western ones in performances. Households can dispose of their waste mercury products at one of these disposal locations businesses can dispose of mercury through a mercury reclamation facility or a hazardous waste management company these lights contain mercury. Mar 15, 2020 a fluorescent lamp is a low weight mercury vapour lamp that uses fluorescence to deliver visible light. For example, a 400watt high pressure sodium lamp produces 50,000 initial lumens. As ac voltage is applied, an arc is struck between the cathodes. In case of fluorescent lamp the mercury vapour pressure is maintained at lower level such that 60% of the total input energy gets converted into 253. Pdf a comparative study on the inactivation of penicillium. The first lamp was a round bulb with two electrodes on each side. Helios quartz uv lamps are the result of a long and solid experience in the market. The analysis of modern low pressure amalgam characteristics.
The irradiances of 37 spectral lines eitted by mercury pencil type lamps were measured by comparison with calibrated continuum sources. Rather than a cold spot, the lamps amalgam spot on pellet regulates mercury vapor pressure during operation and yields up to three times the uvc output. High pressure sodium lamps may be used in open luminaires except for item 67527 lu400t7 rsc and sox low pressure. In this category of lamps about 40% of electricity is converted directly into uvc radiation with monochromatic emission at 254 nm for germicidal applications and at 185 nm for the oxidation of surfaces. Within the tube are two electrode coils, one at either end. Mercury vapor lamps are widely used to light both indoor and outdoor areas such as gymnasiums, factories, department stores, banks, highways, parks, and sports fields. The electric current excites the mercury vapor in the tube, generating radiant energy, primarily in the ultraviolet uv range. These lamps have an operating lifetime of up to 12,000 hours and convert up to 40% of the lamp s electrical power into uvc, offering an efficient and cost. Figure 614 shows the basic configuration of a hid lamp.
High pressure lamps have more components than low pressure and contain other substances such as mercury. Figi separately measured the quantity of nongaseous mercury in the lamp, which is usually in the form of a ball of amalgam a compound of mercury, tin and zinc. The snow white is a lowpressure mercury discharge lamp with a tubular 26 mm envelope, available in 18 w, 36 w and 58 w. Helios quartz uv lamps are suitable for many applications, even the most complex. The arc discharge is generally confined to a small fused quartz arc tube mounted within a larger borosilicate glass bulb. Spores were deposited onto test coupons and controls of four different materials, via liquid suspension or aerosol deposition. Definition of a plasma mixture of electrons, ions and neutral particles in different excited states and with strong. It can come in a high pressure or low pressure format. It includes information on the total amount of mercury in all lamp products that were sold in the u.
As pressure increases the chance of multiple collisions gets increased. Ushios low pressure amalgam lamps are designed with a special coating for longer life. The mercury pellet is converted into a lowpressure mercury vapor and when it mixes with the inert fill gasses, uv photons are produced. Mercury use in lighting this fact sheet summarizes the use of mercury in lighting devices, such as fluorescent lamps, high intensity discharge hid lamps e.
The results were compared with the continuous monochromatic low pressure lpm and medium pressure polychromatic mpm mercury lamps at the uv fluence of. A fluorescent lamp tube is filled with a gas containing low pressure mercury vapor and argon, xenon, neon, or krypton. This is also standard practice in mercury lamps designed for use in colder atmospheres. Advanced technology, careful selection of materials and maximum reliability.
Mercury vapor standard hpl high pressure mercury philips. The test coupons were then exposed to uvc light from either a lowpressure mercury vapor lamp or a system comprised of light emitting diodes, with a range of dosages. Low pressure mercury lamps have been manufactured in jelight company inc. The uv source in low pressure mercury lamps and amalgam lamps that are commonly used for disinfection is a low pressure arcdischarge in mercury and inert gas vapors. The electric current excites the mercury vapor in the tube, generating radiant energy, primarily in the. Uv germicidal low pressure mercuryarc grm ushio america.
Depending on the materials used, mercury low pressure uv lamps can be divided into two large families. The same wattage metal halide lamp produces 40,000 initial lumens, and the 400watt mercury vapor lamp produces only 21,000 initially. The limitation and disadvantage of lamps using ribbon seals is the low peak and rms currents that can be passed through the thin molybdenum ribbons used in the seals, effectively precluding them from being used. At least one manufacturer uses them for a series of krypton arc lamps. Mediumpressure lamps draw a much greater current than lowpressure lamps, leading to a rapid rise in the mercury vapor pressure. Again transition of the electrons requires least amount of input energy from a colliding electron. Per unit area, the effective germicidal output of a mediumpressure lamp is much greater up to 30 times than a lowpressure lamp, allowing high flow rates to be treated using fewer lamps. All the fluorescent or germicidal type lamps cited in this article are hot cathode, low pressure, mercury vapor arc lamps except otherwise noted. Your application requirements will dictate the selection of lamp technology you choose, and will depend. Ballast lowpressure mercury vapor lamps cannot be directly operated on a 115 ac power line. Mercury lamps get dimmer over time and rarely burn out, so it is wise to replace them and restore light level.
The mercury pellet is converted into a low pressure mercury vapor and when it mixes with the inert fill gasses, uv photons are produced. China low pressure mercury lamp, low pressure mercury lamp. Low pressure amalgam lamps amalgam lamps use a mercury amalgam mix to control mercury vapor pressure. Us4199708a lowpressure mercury vapor discharge lamp. In addition to the mercury, the tube is filled with argon gas at low pressure. Best applications for mercury vapor lamps eye lighting. Since the light emitted by a mercuryvapor light has a blue tone, this needs to be accounted for, or color. Conventional low pressure and amalgam lamps are significantly more energy efficient than medium pressure lamps. A fluorescent lamp is a low weight mercury vapour lamp that uses fluorescence to deliver visible light. Amalgam lamps are able to achieve ten times the uv power density of standard low pressure lamps and five times more ozone production while operating at a higher temperature than conventional low pressure mercury lamps.
Amalgam lamps use a mercury amalgam mix to control mercury vapor pressure. It is used for water treatments, uvozone cleaning andor ozone generation. Ogermicidal lamps operate at a very low gas pressure. It also needs to be underlined that mercury is not the only evil in the mercury filled lamps, but other chemicals present in the bulbs have the potential to cause sufficient damage to health. They are available in lengths from the very small at 150 mm to up to 2400 mm. The type of phosphor determines the spectral distribution of the lamp output forbes et al. Mercuryvapor lamp an overview sciencedirect topics. May 22, 20 low pressure sodium lamps are one of the most efficacious light sources. Standard mercury vapor lamps have found greatest use in industrial applications and outdoor lighting, because of their low cost and long life 16,000 to 24,000 hours, with lamp sizes ranging from 40 to 1,000 watts. Ushio germicidal lamps are lowpressure mercuryarc lamps that emit radiation peaking at 253. Germicidal uv lamps standard low pressure lamps from heraeus. Selfballasted mercury lamp applications the most common applications for selfballasted style mercury vapor lamps are. Pulsed uv lamp performance and comparison with uv mercury. Air, water and surfaces disinfection and oxidation, ultraviolet curing, drying of uv glues, paints and varnishes.
Product information high pressure and specification. In low pressure mercury vapor lamps, only the lines at 184 and 253 nanometers nm are present. When a mercury vapor lamp is first turned on, it will produce a dark blue glow because only a small amount of the mercury is ionized and the gas pressure in the arc tube is very low, so much of the light is produced in the ultraviolet mercury bands. Hg2 lowpressure mercury lamps from heraeus noblelight. They produce light when an electric current passes between two electrodes also called cathodes in a tube filled with lowpressure mercury vapor and inert gases, such as argon and krypton. Other lines, which total 20% of the output, are at 3, 365, 404 and 435 nm. It needs to be vaporized and ionized before the lamp can produce its full light output. Now, our more efficient low pressure uv lamps although more efficient, run on around the same power as a regular light bulb around 20 100w making their useful uvc output for a 40w lamp around 24w, a difference of 976w between the w from the medium pressure lamp and this one. Mercury vapor technology was developed throughout the 1800s in england and germany. The lamp is constructed from a hollow glass tube with an aluminium cap at each end. Low pressure sodium lps lamps have a borosilicate glass gas discharge tube arc tube containing solid sodium, a small amount of neon, and argon gas in a penning mixture to start the gas discharge. They produce light when an electric current passes between two electrodes also called cathodes in a tube filled with low pressure mercury vapor and inert gases, such as argon and krypton. The extreme high color temperature of the snow white range creates very cool ambiances, making the lamp especially suitable in very hot and dry climate conditions. Classified as in the same group as fluorescent lamps or germicidal lamps, the main light emission is a 254nm line comprising an 185nm line of far shorter wavelength.
Fluorescent lights contain mercury and must be disposed carefully. Mercury vapor lamps feature low initial cost, but have higher operating costs than hps or metal halide due to its lower efficiency. For more information on how to recycle whole or unbroken fluorescent and other mercurycontaining lamps, see. Inactivation of bacillus anthracis spores on surfaces with. Hg2 lowpressure mercury lamps from heraeus noblelight have a highly stable output predominantly at the 253. Low pressure lp, amalgam low pressure lp and medium pressure mp lamps are all mercurybased lamps. The auxiliary amalgam has a mercury vapor pressure not less than a third as much as the mercury vapor presure of. Aug 20, 2016 a fluorescent lamp tube is filled with a gas containing low pressure mercury vapor and argon, xenon, neon, or krypton. This lamp is based on a standard close to the global standard for lowpressure mercury lamps made in europe and the united states. Lowpressure amalgam lamps amalgam lamps use a mercury amalgam mix to control mercury vapor pressure. The efficacy of the hps lamp is very high as much as 140 lumens per watt. A comparative study on the inactivation of penicillium expansum spores on apple using light emitting diodes at 277 nm and a low pressure mercury lamp at 253.
When a high pressure sodium lamp is to be disposed, it is subject to the current epa toxicity characteristic leaching procedure tclp disposal criteria. Ushio germicidal lamps are low pressure mercury arc lamps that emit radiation peaking at 253. Chapter low pressure discharge lamps slide 7 incoherent light sources prof. A mercury vapor lamp is a gasdischarge lamp that produces light via an electric arc through vaporized mercury. An electric current in the gas excites mercury vapor, which produces shortwave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow. Mercury vapor lamps are highintensity discharge lamps that predate modern highpressure sodium and metal halide lamps. China low pressure mercury lamp manufacturers select 2020 high quality low pressure mercury lamp products in best price from certified chinese outdoor light manufacturers, indoor light suppliers, wholesalers and factory on. Us5204584a low pressure mercury vapor discharge lamp. They produce light when an electric current passes between two electrodes also called cathodes in a tube filled with low pressure mercury vapor and inert gases. Medium pressure lamps produce the greatest uv output per unit length of lamp of the 3 lamp types. The mercury in the tube is a liquid at normal temperatures.
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