Sodium Vapour Lamp

出典: くみこみックス

Sodium Vapour Lamp consists of a discharge tube produced from a heat resistant glass, containing a little quantity of metallic sodium, neon gas and two electrodes, Neon gas is added to commence the discharge and to create sufficient heat to vaporize the sodium. Since of law pressure inside the tube, a sufficiently long tube required to obtain more light. To decrease the overall dimension of the lamp, this tube is usually bent into U-shape.

The light created 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 preserve this temperature. For this goal 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. Even though replacing the inner U-tube 1 must be extremely careful because if it is broken and sodium comes in contact with moisture, it may possibly result in fire.

All electric discharge lamps demand a greater voltage at the time of beginning and low voltage throughout 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 this site the lamp which is enough to commence the discharge. When the lamp is totally operative right after ten - 15 minutes, the voltage across it falls to about 150 volts. Due to the fact of the high reactance of circuit, the power factor is low and therefore discount chicken coops 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 specific wavelength possessing yellow internet chicken coop for 6 chickens color. Sodium lamps are mostly employed for street, high way and airfield lighting where color distinction is not so necessary.