Turn off the high pressure mercury lamp and wait several minutes for it to cool down. Pdf the mercury vapor lamp is the oldest high intensity discharge technology lamp. Ushio germicidal lamps are low pressure mercury arc lamps that emit radiation peaking at 253. 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. Most modern mercury vapor lamps have this rectification done in them. Per unit area, the effective germicidal output of a medium pressure lamp is much greater up to 30 times than a low pressure lamp, allowing high flow rates to be treated using fewer lamps. The combination of uvc and vuv can inactivate airborne pathogens by disrupting the genetic. The luminous efficacy of any discharge lamp falls as wattage is. Mercury vapor lamps feature low initial cost, but have higher operating costs than hps or metal halide due to its lower efficiency. As the main arc strikes and the gas heats up and increases in pressure, the light shifts into the visible range and the high gas pressure.
Best applications for mercury vapor lamps eye lighting. High pressure mercury lamps new approaches are particularly in demand in times of financial and energy crises. Lowpressure sodium lamps are highly efficient electrical light sources, but. The electric current excites the mercury vapor in the tube, generating radiant energy, primarily in the. The tracker 3000 ip portable mercury vapor monitor uses a high frequency driven electrodeless low pressure mercury lamp as uv source. Mercuryvapor lamp an overview sciencedirect topics. Pdf on mercury vapor lamps and their effect on the smartgrid plc. The lamp is constructed from a hollow glass tube with an aluminium cap at each end. Mercury vapor lamps free download as powerpoint presentation. Low pressure sodium lamps were invented first in 1920. This gives a typical diffuse medium pressure uv spectrum see figure 3.
Some include additional substances, like mercury, sodium, and metal halides, which are vaporized during startup to become part of the. Low pressure 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. Medium pressure lamps draw a much greater current than low pressure lamps, leading to a rapid rise in the mercury vapor pressure. The light sources were low pressure mercury vapour lamps having identical geometry and electric parameters 15 w. Sox low pressure sodium lamps sox lamps are the most efficient hid light source.
It gives greenish blue colour light, which causes colour distortion. Mercury vapor lamps street light electromagnetic spectrum. Medium pressure lamps produce the greatest uv output per unit length of lamp of the 3 lamp types. Typically, such lamps use a noble gas argon, neon, krypton, and xenon or a mixture of these gases. Applications of lowpressure mercury vapor lamps for. This lamp emits lines of an extremely narrow bandwidth which are congruent with the absorption lines of the hg atoms. A low pressure mercury vapor discharge lamp having a suitable combination of a main amalgam and an auxiliary amalgam. Us4199708a lowpressure mercury vapor discharge lamp. The first mercury vapor lamps were in a lower pressure tube. Set up the ocular such that the yellow lines are well in focus. Tld08 blacklight blue lamps are low pressure mercury vapor fluorescent lamps.
Investigating the spectrum of a high pressure mercury lamp. Mercury vapor lamps generally contain between 10 and 100 mg of mercury. A fluorescent lamp is a low weight mercury vapour lamp that uses fluorescence to deliver visible light. They produce light when an electric current passes between two electrodes also called cathodes in a tube filled with low pressure mercury vapor. 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. Sodium vapour lamp free download as powerpoint presentation. Within the tube are two electrode coils, one at either end. 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. Working principle of uv lamps uv lamps, ultroviolet, uvc. Low pressure sodium lamps are highly efficient electrical light sources, but their yellow light restricts applications to outdoor lighting, such as street lamps, where they are. Cathode ray tubes crts from computers, televisions, etc may be handled as either electric lamps or consumer electronics universal waste. Low pressure mercury vapour uv lamps home study factors the pressure of several tons, low pressure mercury vapor discharge lamp, while the reaction of mercury mainly 184. Fluorescent lamps3 operate at a very low gas pressure. A sodiumvapor lamp is a gasdischarge lamp that uses sodium in an excited state to produce light at a characteristic wavelength near 589 nm.
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. Low pressure mercury vapor lamps contains mercury and it has harmful effects to an environment and human body. A lamp is a device that illuminates a light on supplying electric current. As pressure increases the chance of multiple collisions gets increased. It,s intensity decays over time, but the bulbs have a longer lifetime. The first practical mercury lamp was the cooperhewitt lamp developed by peter cooper hewitt in 1901. Gasdischarge lamps are a family of artificial light sources that generate light by sending an electric discharge through an ionized gas, a plasma.
Because mercury lamps are so prevalent in current outdoor lighting, and still safe when properly installed in a serviceable fixture, the need for these products will. It is a gasdischarge lamp that uses sodium in an excited state to produce light. Ozone producing low pressure hg vapor lamps emit mainly 254 nm ultraviolet light c uvc with about 10% power of vacuumultraviolet vuv light at 185 nm. Among the light sources in use for general lighting, high pressure mercury vapour h. Mercury lamps get dimmer over time and rarely burn out, so it is wise to replace them and restore light level. The clear mercury bulb has a bluish green appearance and the deluxe white has a higher color rendering. 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. Low pressure amalgam lamps amalgam lamps use a mercury amalgam mix to control mercury vapor pressure. This study is to elucidate the disinfection effect of ozone producing low pressure hg vapor lamps against human pathogens. Download as pptx, pdf, txt or read online from scribd. 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. New high power amalgam lamps are significantly more powerful than low pressure lamps.
Again transition of the electrons requires least amount of input energy from a colliding electron. Note, sodium vapour low pressure lamps generate poor quality. Gas discharge lamps emit light when electric light is passed through the gas. This coating covers more than 70% of the diameter of the lighted length of the lamp. Amalgam lamps use a mercury amalgam mix to control mercury vapor pressure.
Us5204584a low pressure mercury vapor discharge lamp. 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. 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. A common discharge lighting luminary for use in an office environment would typically be a lowpressure mercuryvapour electronic discharge fluorescent lamp. Low pressure mercury vapor lamps cannot be directly operated on a 115 ac power line. A lowpressure mercury vapor discharge lamp which emits light mainly in three spectral ranges, color temperature of light in the absolute temperature of 2,000 to 3,000 range.
The efficacy of vacuumultraviolet light disinfection of. Engineering high intensity discharge bulletin mercury lamps. A sodium vapor 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. In the mercury lamp, light is produced by the passage of an electric current through a gas or vapor under pressure instead of through a tungsten wire as in the incandescent lamp. Mercury vapor standard hpl high pressure mercury philips. The reason for the creation of this second category of mercury lamp was to allow the efficacy to be maintained as high as possible for low wattage sources. Light sources incandescent lamp discharge lamp florescent lamp sodium lamp high pressure mercury vapour lamp 3. When a mercury vapor lamp is to be disposed, it is subject to the current epa toxicity characteristic leaching procedure tclp disposal criteria. A sodium vapor lamp b high pressure mercury vapor lamp c low pressure mercury vapor lamp d neon lamp. Relatively low unit cost and a high average rated life about 24,000 hours. The lumen ratings of low pressure sodium lamps are based on the average performance of large groups of hps lamps operated at their rated watts in the.
The mercury vapor lamp was invented in the year 1901 by peter new york. They have an inner envelope coated with a fluorescent powder that emits longwave uv radiation to. Family full data sheet localized commercial leaflet pdf 541. In fluorescent tubes ballast resistance is connected in series with the choke a when supply frequency is low b to reduce radio interference c when tube operates on dc supply d to reduce stroboscope effects. Mercury vapour pressure is typically around ten atmospheres. Conventional low pressure and amalgam lamps are significantly more energy efficient than medium pressure lamps. White light source xenon lamp has uniform excitation intensities across all the visible range. The low pressure refers to the pressure of the mercury vapour inside the lamp, which is approximately 0. With mercury discharge bulb 5, a light emitting layer 9 means 7, 8 and the absorbent layer 11, 12 and the beam is maintained at the discharge aerated material discharge bulb 5. Low pressure mercury vapor lamps emit 254 nm wavelength of uv which coincides very well with peaks of the germicidal effectiveness curve i. Neon lamps are gas discharge lamps that contain neon gas at a low pressure enveloped in a glass capsule.
What are the advantages and disadvantages of the mercury. Low pressure mercury vapour lamp hg2 lamp heraeus has developed a compact low pressure, low voltage mercury vapour lamp type hg2, principally for use in scientific instrumentation. Mercury vapor lamps, recognizable by the bluish cast of their light, are the least. These lamps ma type are manufactured in 250 and 400 w ratings for use on 200250 v ac supply. The lamps have a socalled negative resistance, meaning that the lamp s electrical resistance falls with rising lamp current. Mercury vapor lamps feature low initial cost, but have higher operating costs than hps or metal halide due to its lower. A fluorescent lamp tube is filled with a gas containing low pressure mercury vapor and argon, xenon, neon, or krypton. The aperture phosphorcoated lamps that jelight company produces employ the same basic design as the doublebore, low pressure mercury vapor lamps with the exception of a special phosphor coating. Hps retrofits for mercury lamps, and will operate on all mercury reactor ballasts. This rectification is done by applying phosphor on the inner surface of the bulb. Sodium vapour lamp incandescent light bulb equipment scribd. Turn on the mercury lamp and observe the double yellow line as the lamp heats up.
Pdf on mercury vapor lamps and their effect on the smart. There are different types of electrical lamps they are, incandescent, mercury, sodium, clf, led lamps. The inner surface of the lamp is coated with a fluorescent and often slightly phosphorescent coating made of varying blends of metallic and rareearth. They emit a characteristic monochromatic yellow light that is ideal for certain exterior street and area lighting applications. This lamp has a highly stable output predominantly at the 253. Lps lamp efficacy and lamp life apogee interactive. All mercury vapor lamps contain some amount of mercury. Low pressure 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. Without some means of limiting the lamp current, the lamp would quickly be destroyed. A low pressure mercury vapor lamp covered with commercial quartz uv lamp, emitting only at 254 nm 5. Product information high pressure and specification. The mercury vapour lamp in construction is similar to sodium vapour 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, such as argon and krypton. Advances in lpuv technology have led to the development of low pressure high output lpho uv lamps, which contain additional elements bismuthindiumgallium rather than pure mercury.
Energy consumption of an energysaving lamp compared to a mercury vapour lamp. Effects of ultraviolet led on bacteria springerlink. Mercury vapor lamps are primarily used in industrial applications and outdoor lighting e. The mercury vapour lamp will soon be obsolete, as it will lose the ce symbol from 2015. The auxiliary amalgam has a mercury vapor pressure not less than a third as much as the mercury vapor.
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