Sodium Vapour Lamp Working Principle
This blog showcases in detail the working of High-Pressure Sodium Vapour Lamp. HPS Lamp is the better version of its counterpart LPS Lamp. Better efficiency, life and size are few of the advantages of HPS Lamp over LPS Lamp.
High Pressure Sodium Lamp: Working Principle
The arc tube consists of frame and is highly pressured with sodium for better efficiency. The arc tube is made of aluminum oxide ceramic which is resistant to the corrosive effects of alkalis like sodium.
The start of lighting up process begins through pulse start. High voltage energy is sent through ignitor through the arc tube. Firstly, the pulse starts an arc through the xenon gas which makes the lamp turns sky blue due to xenon lighting up.
After that the arc then heats up the mercury and the mercury vapor then lights, giving the lamp a bluish color.
Sodium is the last material to vaporize as sodium vapor strikes an arc over 240 C. The sodium is mixed with other impurities to create a more “white” light. The mercury helps add a blue spectrum light to the pure yellow of the sodium.
For maintaining a vacuum, oxygen and other gasses can seep in over time. The getter keeps a stable vacuum by sucking out remaining oxygen and unwanted gas elements. The sodium is stored often stored in the amalgam reservoirs on the ends of the arc tube when it is cool unlike the LPS lamp where the sodium is stored in the bumps on the side of the tube