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| − | Sodium Vapour Lamp consists of a discharge tube made from a heat resistant glass, containing a modest amount of metallic sodium, neon [http://www.chickencoopselect.com/ follow us on twitter] gas and two electrodes, Neon gas is added to start off the discharge and to create enough heat to vaporize the sodium. Simply because of law pressure inside the tube, a sufficiently long tube necessary to acquire much more light. To decrease the overall dimension of the lamp, this tube is generally bent into U-shape.<br><br>The light produced by this lamp is yellowish which is made at its optimum pressure of about .004mm of mercury. This pressure is obtained at a temperature of about 280 C and so it becomes essential to sustain this temperature. For this purpose the U-tube is enclosed in a double walled flask to avoid shed of heat. The double walled flask is interchangeable and can be fitted on to an additional U-tube. Even though replacing the [http://www.chickencoopselect.com/chicken-tractors chicken coop tractor] inner U-tube 1 need to be quite careful due to the fact if it is broken and sodium comes in contact with moisture, it could [http://www.chickencoopselect.com/chicken-tractors tell us what you think] result in fire.<br><br>All electric discharge lamps call for a greater voltage at the time of starting and low voltage for the duration of operation. Generally, sodium vapour lamps are operated by a high leakage reactance transformer. At starting a high voltage of about 450 volts is applied across the lamp which is adequate to start off the discharge. When the lamp is fully operative right after ten - 15 minutes, the voltage across it falls to about 150 volts. Due to the fact of the high reactance of circuit, the power factor is low and hence a p.f improvement capacitor is connected.<br><br>The efficiency of a low pressure sodium vapour lamp is really high (about 40 - 50 lumens/watt) and it produces a light of specific wavelength getting yellow color. Sodium lamps are mainly employed for street, high way and airfield lighting exactly where color distinction is not so essential.
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Текущая версия на 11:44, 26 декабря 2025
