Sodium Vapour Lamp

Sodium Vapour Lamp consists of a discharge tube created 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 create sufficient heat to vaporize the sodium. Because of law pressure inside the tube, a sufficiently extended tube essential to acquire much more light. To lessen the all round dimension of the lamp, this tube is typically bent into relevant webpage U-shape.

The light developed by this lamp is yellowish which is developed 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 keep this temperature. For this objective the U-tube is enclosed in a double walled flask to avert lose of heat. The double walled flask is interchangeable and can be e cigarette liquid fitted on to one more U-tube. Although replacing the inner U-tube one particular have to be extremely cautious due to the fact if it is broken and sodium comes in make contact with with moisture, it may outcome in fire.

All electric discharge lamps need a greater voltage at the time of starting and low voltage throughout operation. Typically, sodium vapour lamps are operated by a high leakage reactance transformer. At beginning a high voltage of about 450 volts is applied across the lamp which is sufficient to start off the tour electronic cigarette brands discharge. When the lamp is totally operative following 10 - 15 minutes, the voltage across it falls to about 150 volts. Due to the fact of the high reactance of circuit, the power aspect is low and hence 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 distinct wavelength having yellow color. Sodium lamps are mostly employed for street, high way and airfield lighting where color distinction is not so essential.