types of discharge lamps
This tube is filled with noble gas and often also contains suitable metal or metal salts. Discharge lamp types include low pressure mercury (fluorescent), induction, high pressure mercury vapour, mercury-blended, metal halide, low pressure sodium and high pressure sodium. . A mercury-vapor lamp is a gas discharge lamp that uses mercury in an excited state to produce light. It is filled with xenon to help start the arc, as well as a sodium-mercury gas mixture. Many HID lamps are designed to quickly extinguish if their outer UV-shielding glass envelope is broken. Mercury vapor lamps (and their relatives) are often used because they are relatively efficient. Unless designed to generate UV (for medicinal purposes, photoengraving, or whatever), the short wave radiation will be blocked by the outer Types of Gaseous Discharge Lamps: ADVERTISEMENTS: 1. Sodium Vapour Discharge Lamp: Principally the sodium vapour discharge lamp consists of a bulb containing a small amount of metallic sodium, neon gas, and two sets of electrodes connected to a pin type base. One Caterpillar HID … Because of the good color rendition and high lumen output, these lamps are good for sports arenas and stadiums. Therefore, they are called reflector lamps and are also called floodlighting, spotlighting, and down lighting bulbs. The method used to initially strike the arc varies: mercury-vapor lamps and some metal-halide lamps are usually started using a third electrode near one of the main electrodes, while other lamp styles are usually started using pulses of high voltage. From about 1900, practical electric discharge lamps were in use in Europe and the United States. Viele übersetzte Beispielsätze mit "high intensity discharge lamp" – Deutsch-Englisch Wörterbuch und Suchmaschine für Millionen von Deutsch-Übersetzungen. Below are HID sources, listed in increasing order of efficacy (lumens per watt): Like fluorescent lights, HID also requires ballasts, and they take a few seconds to produce light when first turned on because the ballast needs time to establish the electric arc. 1. Definition: light sources which are based on an electrical discharge in an ionized gas or metal vapor.  The thorium, which is a solid, is used in the electrodes.. The efficacy of low-wattage "white" HPS lamps is lower than that of metal halide lamps (lumens per watt of low-wattage metal halide is 75-85, while white HPS is 50-60 LPW). These additives enable the lamp to produce more visible light per watt with improved color rendition. Exposure to HID lamps operating with faulty or absent UV-blocking filters causes injury to humans and animals, such as sunburn and arc eye. In this type of lamps the cathodes need to be heated in order for them to emit electrons and form the arc. 2217 Earth and Engineering Sciences Building, University Park, Pennsylvania 16802 Common Characteristics of HID Lamps All HID lamps have a warm-up period that lasts from 3-10 minutes (depending on the type and wattage) before it produces full light output  However, this HID technology is not new and was first demonstrated by Francis Hauksbee in 1705. Contact Us, Privacy & Legal Statements | Copyright Information street signs and pedestrians) left in the shadows by standard halogen lighting. Types of Lighting: Low-pressure sodium. They are also used to reproduce tropical intensity sunlight for indoor aquaria. What event(s) occurs to actually produce the light we see? The arc tube is made of a ceramic material which can withstand temperatures up to 2,372°F. Discharge lamps are often classed as high pressure or low pressure, although these terms are only relative, and a high-pressure sodium lamp operates at below one atmosphere. A high-frequency field (c. 27 MHz) leads to a plasma within the tube, in which the element is excited and emits specific light. mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps (details of electron-optical arrangements or of ion traps H01J 3/00) Definition statement This place covers: Details of electrodes, or magnetic control means, of screens, or of the mounting or spacing thereof, of an unspecified kind of discharge tube or discharge lamp, e.g. Historically, discharge lamps represented, in the nineteenth century, the first forms of electric lighting, even before the invention of the incandescent lamps. Once the arc is started, it heats and … Gas-discharge lamps are a family of artificial light sources that generate light by sending an electrical discharge through an ionized gas, a plasma.Typically, such lamps use a noble gas; (argon, neon, krypton, and xenon) or a mixture of these gases.Some include additional substances, like mercury, sodium, and metal halides, which are vaporized during startup to become part of the gas mixture. mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps (details of electron-optical arrangements or of ion traps H01J 3/00) Definition statement This place covers: Details of electrodes, or magnetic control means, of screens, or of the mounting or spacing thereof, of an unspecified kind of discharge tube or discharge lamp, e.g. Print. Discharge lamp types are mainly classified as three types and those are: Low-pressure Discharge Lamps. Glow discharge in gases is used in many types of electronic devices (gas lasers, plasma display panels, discharge illuminating lamps)   . Sodium, the major element used, produces the "golden" color that is characteristic of HPS lamps. Whether a discharge lamp has reached the end of its ‘rated life’1, the end of its ‘economic life’2, or is to be replaced for an LED lighting system, will require care in their safe disposal. This type of lamp involves an internal electrical discharge being created between two electrodes in a gas filled chamber; the level of intensity generated by a discharge lamp can vary, and can range from low level wattage bulbs through to extreme intensities that can be used for filling large areas with light. Names for specific types of lamps can refer to different such aspects; for example, a neon lamp indicates that a discharge in neon gas is used (possibly with added other gases), a glow lamp is recognized to work in the glow discharge regime, a high pressure lamp obviously uses a relatively high gas pressure, and a flash lamp is used for producing light pulses. Originally they produced a bluish-green light, but more recent versions can produce light with a less pronounced color tint. HID lamps have a "restrike" time, meaning a momentary interruption of current or a voltage drop too low to maintain the arc will extinguish the lamp. High-intensity discharge (HID) lamps are similar to fluorescents in that an arc is generated between two electrodes. Factors of wear come mostly from on/off cycles versus the total on time. h. Discharge Lamps: Light in a discharge lamp is produced by the electric arc between the tungsten electrodes, that is kept inside a translucent or transparent fused quartz. HID lamps have also become common on many aircraft as replacements for traditional landing and taxi lights. Grp. s. Here at Edwardes Bros we are proud to stock a high quality and varied range of Discharge lamps. Metal-halide and ceramic metal-halide lamps can be made to give off neutral white light useful for applications where normal color appearance is critical, such as TV and movie production, indoor or nighttime sports games, automotive headlamps, and aquarium lighting. The presence of neon gas serves to start the discharge and to develop enough heat to vaporize the sodium. 12. Experiments show promising results and widespread future applications are expected. This courseware module is part of Penn State's College of Earth and Mineral Sciences' OER Initiative. Hot cathode lamps have electrodes that operate at a high temperature and are heated by the arc current in the lamp. Types and characteristics of discharge lamps. The highest wear occurs when the HID burner is ignited while still hot and before the metallic salts have recrystallized. This makes them particularly effective as photographic safelights. As for various other types of gas discharge lamps, for a metal halide lamps one requires a special lamp power supply, providing a well stabilized DC current and the required triggering features. They are known to last for a considerable period of time and you can find them in car and other vehicle headlights. As the lamp heats to this point, the arc fails and the lamp goes out. More sophisticated ballast designs detect cycling and give up attempting to start the lamp after a few cycles. High intensity Discharge Lamp refers to a high-pressure gas discharge lamp that is filled with a mixture of inert gases including xenon, but does not have the filament of a halogen lamp, referred to as HID xenon lamp. The color may vary from lamp to lamp and may shift over the life of the lamp and during dimming. 10. These discharge lamps operate at minimal atmospheric pressure levels. New color-corrected versions producing a whiter light are now available, but some efficiency is sacrificed for the improved color. Eg: sodium vapour, mercury vapour and neon gas. There are four basic types of lamps considered as HID light sources: Mercury vapour, Low pressure sodium, High pressure sodium and; Metal halide. It can also be called a metal halide lamp. The high-pressure sodium (HPS) lamp is widely used for outdoor and industrial applications. All are arc discharge lamps. Wattages range from 32 to 2,000, offering a wide range of indoor and outdoor applications. With the immunity of the self-ballasted lamps, auxiliary equipment (starters and ballasts) must be provided for … Eventually, with the arc extinguished, the lamp cools down again, the gas pressure in the arc tube is reduced, and the ballast can once again cause the arc to strike. All are arc discharge lamps. Brand new high-intensity discharge lamps make more visible light per unit of electric power consumed than fluorescent and incandescent lamps, since a greater proportion of their radiation is visible light in contrast to infrared. The noble gas enables the arc's initial strike. The site editor may also be contacted with questions or comments about this Open Educational Resource. Alternatively, one may apply a high-frequency AC current, often with a rectangular voltage profile to avoid any interruptions of the discharge. Mercury lamps also require special waste disposal, depending on location. Shortwave UV, a result of the decay of mercury atom electrons from an excited to a stable state, is readily transmitted through the inner quartz tube but is virtually blocked by the outer glass envelope during normal operation. incandescent lamp. Mercury vapor lamps consist of an inner arc discharge tube constructed of quartz surrounded by an outer hard borosilicate glass envelope. Other types of high pressure gas discharge lamps: High pressure sodium lamps Containing sodium amalgam Aluminium oxide arc tube High pressure leads to broadened spectrum Used for street lighting, plant cultivation Types of gas light sources Artificial Light Sources • Incandescent Lamps • Fluorescent Lamps • High – Intensity Discharge Lamps • Mercury Lamps • Metal Halide Lamps • High Pressure Sodium Lamps • Low Pressure Sodium Lamps • Electrodeless Lamps • Compact arc xenon &Mercury Lamps • Electroluminescent Lamps • Light Emitting Diodes (LED) • Carbon arc Lamps • Gaslights A complete list of Low Pressure Sodium (SOX) , High Pressure Sodium (SON), Mercury Blended Fluorescent (MBF) and all High Intensity Discharge Metal Halide Lamps in all caps and colours. Please send comments or suggestions on accessibility to the site editor. Low pressure sodium lamps, the most efficient gas-discharge lamp type, producing up to 200 lumens per watt, but at the expense of very poor color rendering. Based on Planck's law, this is a direct result of the increased voltage and higher temperature necessary to maintain the arc. This shift is slight at first and is more generally a sign of the lamps being "broken in" whilst still being in good overall working order, but towards the end of its life, the HID lamp is often perceived as only producing blue and violet light. If power is removed and reapplied, the ballast will make a new series of startup attempts. 11. Mercury-vapor lamps were the first commercially available HID lamps. The light-producing element of these lamp types is a well-stabilized arc discharge contained within a refractory envelope (arc tube) with wall loading in excess of 3 watts-per-square-centimeter (W/cm²) … High-intensity discharge (HID) lamps include several types of electrical lamps: mercury-vapor, metal halide (also HQI), high-pressure sodium, low-pressure sodium and less common, xenon short-arc lamps. The effect of this is that the lamp glows for a while and then goes out, repeatedly. Moreover, the presence of thorium in electrodes reduces the work function which again results in easier arc starting and sustaining. These isotopes produce ionizing radiation of alpha and beta type. How do the spectra of Hydrogen, Mercury, and Sodium on the PhET site compare to the spectra on our Spectrum Poster in the front of the room? A gas discharge lamp is a light source that generates light by creating an electrical discharge through an ionized gas. High-intensity discharge lamps are a type of arc lamp. The arc discharge is generally confined to a small fused quartz arc tube mounted within a larger borosilicate glass bulb. Low-pressure sodium lamps—producing up to 180 lumens per watt—have the highest efficacy of all commercially available lighting sources. Mercury and sodium are the most common metal vapors employed in discharge lamps. The noble gas enables the arc's initial strike. HID lamps have made indoor gardening practical, particularly for plants that require high levels of direct sunlight in their natural habitat; HID lamps, specifically metal-halide and high-pressure sodium, are a common light source for indoor gardens. An electric current passed through a gas will excite the atoms and molecules to emit radiation of a spectrum which is characteristic of the elements present. This radiation causes high ionization inside the lamp without being able to escape from the lamp. Varieties of HID lamp include: The light-producing element of these lamp types is a well-stabilized arc discharge contained within a refractory envelope arc tube with wall loading in excess of 3 W/cm² (19.4 W/in²). There are three high intensity discharge (HID) lamps: mercury vapor (MV), metal halide (MH), and high-pressure sodium (HPS). Preheat lamps are the oldest type of Discharge Lamps. A mercury vapor (MV) light is one type of HID lamp. MV and MH lamps have a separate staring electrode, along with the two operating electrodes of the arc tube. Gas-discharge lamps are a family of artificial light sources that generate light by sending an electric discharge through an ionized gas, a plasma. The arc in an HID source is shorter, yet it generates much more light, heat, and pressure within the arc tube. In many types the electrodes consist of electrical filaments made of fine wire, which are heated by a separate current at startup, to get the arc started. Gas discharge lamps are used in virtually all areas of modern lighting technology including common fluorescent lighting for home and office - and LCD backlights for laptop computers, high intensity discharge lamps for very efficient area lighting, neon and other miniature indicator lamps, germicidal and tanning lamps, neon signs, photographic electronic flashes and strobes, arc lamps for industry and A/V … Discharge lamps, like most other types of lamp, have a ﬁnite life. High-intensity discharge lamps (HID lamps) are a type of electrical gas-discharge lamp which produces light by means of an electric arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tube. Mercury vapour in a neon lamp gives a bluish light; mercury is used also in fluorescent lamps and some ultraviolet lamps. As the HID lights use less than half the power of an equivalent tungsten-halogen light, a significantly smaller and lighter-weight power supply can be used. Although HPS lamps are not generally recommended for applications where color rendering is critical, HPS color rendering properties are being improved. Divided into xenon lamps for automobiles and xenon lamps for outdoor lighting. 13. See More: Types of Fans and Their Uses. Two metals are commonly used, sodium and mercury, because their characteristics give useful radiations within the visible spectrum. , Some HID lamps make use of radioactive substances such as krypton-85 and thorium. High Pressure Discharge. As a lamp gets older, the voltage necessary to maintain the arc eventually rises to exceed the voltage provided by the electrical ballast. What types of electromagnetic radiation are produced? The Pennsylvania State University © 2020, Energy Conservation for Environmental Protection, Energy Conservation and Environmental Protection, Types of Lighting: Low-pressure sodium ›, Types of Lighting: High-intensity Discharge, Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, Department of Energy and Mineral Engineering, Department of Materials Science and Engineering, Department of Meteorology and Atmospheric Science, Earth and Environmental Systems Institute, iMPS in Renewable Energy and Sustainability Policy Program Office, BA in Energy and Sustainability Policy Program Office, 2217 Earth and Engineering Sciences Building, University Park, Pennsylvania 16802, Relatively long life (5,000 to 24,000+ hrs).