Incandescent light bulbs emit warm color light when working, and have excellent color rendering (color rendering index Ra=100), and they have been widely used lighting sources for a long time since their birth. Although the use of high-pressure sodium lamps has many advantages, the color rendering is poor (Ra=30).
In order to maintain the long life, high luminous efficiency, and warm tone atmosphere of the high-pressure sodium lamp; in terms of improving the color rendering, people have developed high color rendering high-pressure sodium lamps that meet the above requirements through tireless efforts.
The high color rendering high-pressure sodium lamp is based on the high-pressure sodium lamp and adopts measures such as increasing the sodium vapor pressure and increasing the diameter of the arc tube, and at the same time wrapping a layer of niobium foil on both ends of the arc tube and increasing the temperature of the cold end to improve the color rendering. In addition, increase the pressure of xenon gas charged into the arc tube, so that the temperature of the central part of the arc rises, while the temperature of the rest of the discharge part is lower, and the color rendering is improved by changing the temperature distribution of the arc, and the color rendering index has been increased to Ra =70 ~ 80, the luminous efficiency can reach more than 80 lm/w, which can broaden the application field and make it a reality to replace incandescent light bulbs with high color rendering high-pressure sodium.
