Sodium lamps, also known as SON lamps, are available in both elliptical and tubular shaped versions. They boast long lifespans, usually around 15000 to 30000 hours, but upwards of 50000 hours in long life models. They also have high luminous output while being cheap to run. The finish of the lamps is clear and is available in a broad range of wattages.
Sodium-E - These lamps are often used for areas that need bright consistent lights such as car parks, residential areas, and road lights. They omit a pleasing golden white light but are poor for rendering colour accurately. These lamps will take a few minutes to reach full output from start-up and are not designed to be restarted once hot.
Sodium-T - These are high pressure sodium lamps that have the same characteristics as sodium-E lamps, but are tubular. These lamps usually have a clear finish, and just like sodium-E lamps, they are available in a broad range of wattages.
These sodium lamps boast long lifespans of usually around 15000 to 30000 hours, but have been known to upwards of 50000 hours. They are cheap to run and with such a long time they do not require maintenance frequently, with these lamps being in hard to reach areas.