Industry
Fact-checked

At AboutMechanics, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What are Metal Halide Lamps?

Paul Scott
Paul Scott

Metal halide lamps are gas discharge light sources which provide illumination by passing an electric arc through a high pressure argon, mercury, and metal halide mixture. Similar in operation to fluorescent and mercury vapor lamps, metal halide lamps are distinct because of their high light output and different color casts. Due to their relatively small size and high power ratings, these lamps are widely used in stadium lighting, factories, warehouses, and outdoor flood lighting applications. Metal halide lamps are available in a fairly wide range of power ratings which typically include 150 to 1,200 watt variants. These lamps require a special ballast fitting to operate correctly, the cost of which is normally justified by long service life and excellent performance.

Gas discharge lamps belong to a family of lighting sources known as high intensity discharge (HID) lamps. These lamps are well suited to applications where high lumen output is necessary because they are particularly powerful for their size. They are also useful where a particular color cast is required because each type has a specific metal salt added to its interior which produces different light hues. Metal halide lamps operate by passing a high tension electric arc through a pressurized mixture of argon and mercury gas to which metal halides have been added. Metal halides are ionic halide salts which are included in the mixture to influence the lamps' specific color temperature or hue.

Worker
Worker

Expansive outdoor venues and large interior volume spaces are environments which benefit considerably from the use of metal halide lamps. Typical applications of this type of lamp include sports venue lighting, outdoor security lighting, warehouses, and factories. The color cast features of the lamps can also be tailored to closely simulate day light. Other common uses include theatrical, photographic studio, and movie set lighting. Reef aquarists also use metal halide lamps as a high intensity light source for growing corals.

These lamps are available in a wide selection of power ratings, with 150, 250, 400, 575, and 1,200 watt variants being the most popular. Metal halide lamps require a special fitting to function correctly as their high tension arc requires the inclusion of a ballast in the fitting. Any additional costs involved are, however, adequately offset by good lighting qualities and lengthy service life. This family of lamps cannot produce its full light potential below a certain operating temperature and feature a distinctive “warm-up” period where each glows dimly and changes color. Metal halide lamps should ideally be used with closed fittings when suspended over high traffic areas as an arc tube failure can sometimes cause the outer tube to shatter.

Discussion Comments

lighth0se33

There is a three-story house down my street that has outdoor security lighting bright enough to make the house look like the sun is shining on it. The flood lights that shine on the front of the house use metal halide bulbs.

The house looks really beautiful at night, because it is the only thing in the area that you can clearly see. Maybe the owners enjoy showing it off like this, but I think the main reason behind the flood lights is security.

These lights are so bright that no criminal would dare to attempt a break-in. If he did, then he would put himself in extreme danger of being seen by a neighbor. Since we have a neighborhood watch, this would be a bad idea.

Oceana

My school's football field has metal halide fixtures. They are basically big flood lights on top of tall poles, and they are strong enough to light the field, the bleachers, and everyone in the area.

Even when it's very dark outside, it is easy to see everything going on in the field. It's also easy to find your way to the bathroom and the concession stand. I'm sure that this helps increase food and drink sales during the event.

I'm glad that the fixtures are way up high, because swarms of bugs are attracted to them. If they were lower, then we might have a problem. I think they actually draw the bugs away from the crowd and help everyone to enjoy the game more.

cloudel

@kylee07drg – That is strange. The warehouse where my husband works uses metal halide light bulbs, but they emit a bright white light.

He has to read numbers on boxes in order to pick them off the shelves, so he needs sufficient light for this. Also, he has to go in at 4 a.m., so the bright light helps to wake him up and trick his mind into thinking it is daylight.

I would imagine that a light with less intensity would make the workers less alert, which would be a safety hazard. They all drive lifts around for hours and have to be careful not to run into each other. They also have to watch out for spills where anyone else may have dropped a box of orange juice or eggs while trying to load them up.

kylee07drg

I guess the metal halide lights inside the factory where my mother works are the reason for the greenish tint to the air. I don't know why the owners would want that color cast in there.

To me, it makes the place seem toxic or alien. It definitely does not resemble natural light.

Maybe it was the cheapest kind that the factory owner could find. At least it isn't bright yellow. That color would probably give everyone a headache after awhile.

My mother doesn't complain about the lighting. She said it kind of calms her and helps her concentrate. Perhaps this is the psychological effect the company was trying to achieve.

Post your comments
Login:
Forgot password?
Register:
    • Worker
      Worker