There are two kinds of sodium lights: Low Pressure (LPS) and High Pressure (HPS). These lamps are mostly used for street lighting as well as industrial uses. The lamp works by creating an electric arc through vaporized sodium metal. Other materials and gases are used to help start the lamp or control its color.
Why sodium is used in street lights?
It is most visible in street lighting. Sodium-vapour lamps are good for night-time illumination because of their high efficiency and because the light they produce penetrates mist and fog particularly well.
Why is sodium light yellow?
As current flows through the electrode, the metal is heated. In the vapor state, the sodium electrons are excited to higher energy levels When these electrons return to a lower energy level, light is given off. The yellow color is a product of the light emitted by the sodium electrons.
Does sodium emit light?
As a result the valence electron present in sodium atoms become excited and emit light. The wavelength of the emitted light is 590 nanometers, which correspond to yellow light. Sodium Vapor lamps emit yellow light only.
What color is high pressure sodium light?
HPS bulbs actually produce a dark pink glow when first struck, and an intense pinkish orange light when warmed. HPS Lamps are favored by indoor gardeners for general growing because of the wide color-temperature spectrum produced and the relatively efficient cost of running the lights.
How long do sodium bulbs last?
High Pressure Sodium lights maintain their luminescence fairly well with 90% still available halfway through their lifespan (around 12,000 hours). HPS bulbs typically emit 80% of their original rated output at the end of life (around 24,000 hours).
Why Initially sodium light is pink or red?
When the lamp is first turned on the sodium is not properly vaporised yet. Instead it is effectively a low light neon/argon light with some red from the neon, and some violet from the Argon. The combination of these two colours creates , pink light. This is where the pink colour comes from.
Why are street lights yellow and not white?
Streetlights and industrial lights, such as those found in parking garages or manufacturing facilities, give off a yellowish or orange glow because they are sodium vapor gas-discharge lights. There are two types of sodium vapor lights, high pressure (HPS) and low pressure (LPS).
Can HPS bulbs explode?
The internal pressure of HPS and LPS is lower than that of the surrounding air, so there is no risk of explosion.
Why are some street lights purple now?
Streetlight LED bulbs would normally appear a little blue, so the manufacturer coats the bulb to turn the blue light into the bright white that comes to mind when you think of an LED. A defect in the coating is causing it to peel away on some bulbs, producing the purple hue, Cullen said.
What are HPS grow lights?
High pressure sodium (HPS) grow lights are one half of a standard HID (high intensity discharge) grow system. Producing a red spectrum light, HPS grow lights are used to replace MH (metal halide) bulbs once your plants have entered the flowering stage.
Are high pressure sodium lights being phased out?
Phasing out
A number of popular lighting types will have to be phased out by 2017 including selected ‘standard’ high-pressure sodium (including retrofit), high-pressure mercury, and standard performance metal halide.
Can you put a LED bulb in a high pressure sodium fixture?
Higher wattage LED replacement bulbs are referred to as corn lights because the rows of LED chips on the lamp look similar to the rows of cob on an ear of corn! LED corn cob lights are one of the most efficient ways to replace metal halide, mercury vapor, and high-pressure sodium HID bulbs.
Is sodium light a monochromatic light?
The light of a single wavelength is called monochromatic light, e.g., Sodium lamp is a source of monochromatic light.
What color is high pressure?
High pressure is colored in blue. The choice of the color blue has nothing to do with temperature. High pressures can bring with warm or cold weather depending on the type of high pressure it is. Low Pressure System: This is a region of relatively lower pressure.
Is HPS better than LED?
Essentially, we’re talking about different technologies and calling them both “HPS.” LEDs are much the same. Though they’re generally more efficient than HPS (with some clocking 2.8 µmol/joule), some LEDs are less efficient than high-quality HPS fixtures, and they give you less light.
What is the efficacy of a low pressure sodium lamp?
Most energy efficient light source commercially available, with an efficacy of 100 to 185 lumens per watt. Lamps have average life in the 14,000 to 18,000 hour range and have excellent lumen maintenance (very little reduction in lumen output over life of lamp).
