Sodium Vapour Lamp

Sodium Vapour Lamp consists of a discharge tube made from a heat resistant glass, containing a tiny amount of metallic sodium, neon 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 needed to acquire a lot more light. To lessen the overall dimension of the lamp, this tube is normally bent into U-shape.

The light made 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 necessary to sustain this temperature. For this goal the U-tube is enclosed in a double walled flask to prevent lose of heat. The double walled flask is interchangeable and can be fitted on to one more U-tube. Although replacing the inner U-tube 1 have to be very cautious because if it is broken and sodium comes in speak to with moisture, it may possibly outcome in fire.

All electric discharge lamps demand a higher voltage at the time of starting and low voltage in the course of operation. Usually, sodium vapour lamps are operated [http://www.chickencoopselect.com/ commercial chicken coop house buy chicken coop kits] by a high leakage reactance transformer. At starting a high voltage of about 450 volts is applied across the lamp which is adequate to begin the discharge. When the lamp is totally operative after ten - 15 minutes, the voltage across it falls to about 150 volts. Since of the high reactance of chickencoop circuit, the power issue 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 particular wavelength possessing yellow color. Sodium lamps are primarily employed for street, high way and airfield lighting where color distinction is not so needed.