Sodium Vapour Lamp

Sodium Vapour Lamp consists of a discharge tube produced from a heat resistant glass, containing a modest amount of metallic sodium, neon gas and two electrodes, Neon gas is added to start the discharge and to develop enough heat to vaporize the sodium. Since of law pressure inside the tube, study hen houses for sale a sufficiently long tube required to obtain more light. To lessen the overall dimension of the lamp, this tube is normally bent tumbshots into U-shape.

The light created by this lamp is yellowish which is produced at its optimum pressure of about .004mm of mercury. This pressure is obtained at a temperature of about 280 C and so it becomes needed to retain this temperature. For this goal 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 another U-tube. While replacing the inner U-tube 1 have to be quite cautious simply 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 larger 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 enough to start the discharge. When the lamp is completely operative following ten - 15 minutes, the voltage across it falls to about 150 volts. Because of the high reactance of 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 quite high (about 40 - 50 lumens/watt) and it produces a light of quality small chicken house distinct wavelength possessing yellow color. Sodium lamps are mostly employed for street, high way and airfield lighting exactly where color distinction is not so essential.