Popularize science and spread science to the public! Click the blue words above to follow us This article was reviewed by Jingjing Xu, PhD in Physical Electronics, Peking University At the end of a day's work Dragging my tired body on the way home Looking at the road dotted by street lamps The whole city feels exceptionally bright I am also surrounded by warmth but Have you ever thought about Why do most street lamps emit light? All yellow Instead of white? today Just to unravel it for everyone The secret … turn out to be The street lights we see Most of the installed high pressure sodium lamps It mainly relies on metallic sodium vapor to emit light When first opened, it appears white After some time It will turn yellow That's the color of metallic sodium. In the street lamp industry Why choose high pressure sodium lamp There is a reason for this. First of all, high pressure sodium lamps have a very high luminous efficiency. An electric light source Secondly, strong penetration Even in foggy weather Everyone can also stay within a certain range on the road See the road clearly Furthermore, it consumes less power High pressure sodium lamps can Lights up at lower voltage Very cost-effective to use Finally, the light is soft No eye irritation Can greatly reduce the incidence of traffic accidents Do you understand now? The pictures in this article with the "Science Popularization China" watermark are all from the copyright gallery. The pictures are not authorized for reprinting. |
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