Sodium Vapour Lamp

出典: くみこみックス

Sodium Vapour Lamp consists of a discharge tube made from a heat resistant glass, containing a small amount of metallic sodium, neon gas and two electrodes, Neon gas is added to start the discharge and to create adequate heat to vaporize the sodium. Simply because of law pressure inside the tube, a sufficiently lengthy tube needed to obtain a lot more light. To lessen the general dimension of the lamp, this tube is generally bent into U-shape.

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 chicken coop houses online of about 280 C and so it becomes necessary to preserve this temperature. For this objective the U-tube is enclosed in a double walled flask to stop lose of heat. The double walled flask is interchangeable and can be fitted on to an additional U-tube. While replacing the inner U-tube one particular should be extremely careful since if it is broken and cheap chicken coop buy sodium comes in make contact with with moisture, it may possibly outcome in fire.

All electric discharge lamps demand a higher voltage at the time of beginning and low voltage throughout operation. Normally, sodium vapour lamps are operated open site in new window by a high leakage reactance transformer. At beginning a high voltage of about 450 volts is applied across the lamp which is sufficient to commence the discharge. When the lamp is totally operative immediately after 10 - 15 minutes, the voltage across it falls to about 150 volts. Due to the fact of the high reactance of circuit, the power element is low and therefore a p.f improvement capacitor is connected.

The efficiency of a low pressure sodium vapour lamp is very high (about 40 - 50 lumens/watt) and it produces a light of distinct wavelength getting yellow color. Sodium lamps are primarily employed for street, high way and airfield lighting exactly where color distinction is not so needed.