Sodium Vapour Lamp

出典: くみこみックス

2012年8月12日 (日) 23:43の版

Sodium Vapour Lamp consists of a discharge tube produced from a heat resistant glass, containing a tiny quantity of metallic sodium, neon gas and two electrodes, Neon gas is added to begin the discharge and to create sufficient heat to vaporize the sodium. Due to the fact of law pressure inside the tube, a sufficiently long tube required to acquire much more light. To decrease the all round dimension of the lamp, this tube is generally bent into U-shape.

The light produced by this lamp is yellowish which is developed at its optimum pressure get reviews electronic cigarettes of about .004mm of mercury. This pressure is obtained at a temperature of about 280 C and so it becomes needed to preserve this temperature. For this objective 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 an additional U-tube. While replacing the inner U-tube one particular need to be extremely cautious because if it is broken and sodium comes in contact with moisture, it could outcome in fire.

All electric discharge lamps call for a greater voltage at the time of beginning and low voltage for the duration of operation. Normally, 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 off the discharge. When the lamp is completely operative right after 10 - 15 minutes, the voltage across it falls to about 150 volts. Because of the high reactance of circuit, the power aspect 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 smokestik critique it division produces a light of particular wavelength getting yellow color. Sodium lamps are primarily employed for street, high way and airfield lighting where color distinction is not so necessary.