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