In a living room or office, a light bulb is enough, the power of which varies from 60 to 150 watts. But they will be too dim for studio, decorative, or street lighting. For this, there are special metal halide lamps. Their features and characteristics differ significantly from other products, which is important to consider when choosing.
What it is?
Metal halide lamps (MGL) are gas-discharge lighting sources, which means that light is emitted due to an electric discharge in metal vapors. The key feature of such products is use of special additives in the form of vapors of mercury and halides of several chemical componentsthat are in a gaseous environment.
When the light bulb is inactive, all additives are deposited on the surface of the burner. When heated, this "precipitate" begins to evaporate, accompanied by decomposition into ions. When excited, ionized metal atoms emit light.
The emission spectrum of metal halide lamps is quite wide - from warm light to cold light, so they can be comfortable for illumination. In addition, such models are very economical, since they consume little electricity. Their service life is also an advantage - they work up to 15 thousand hours.
However, one should also take into account the disadvantages of these lamps. These light sources harmful to the human body due to the content of mercury and other chemical elements. And because of the significant heat release, the height of their location is limited.
Types and characteristics
Metal halide lamps have different wattage, so there is always an opportunity to choose the most optimal option for work and other matters.
There are several types of such bulbs, the classification of which occurs depending on the following indicators:
- Power. To connect to an electrical network, the voltage of which is 220 Volts, products with a power of 20 W or more are used, but not more than 2000 W. Such lamps are used where the voltage reaches 380 volts.
- Radiated shades. This attribute type can emit a colored luminous flux: blue, magenta, green, etc.
Working position. There are bulbs that only function in one position: horizontal or vertical. However, there are universal models - they work in any position
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Construction type:
- Baseless. This type does not have a base, and its power ranges from 2 thousand to 3.5 thousand watts. The connection is made thanks to flexible down conductors.
- Single-capped. Among their wide variety there are models that work only in a horizontal or vertical position, as well as those that work normally in both positions.
- Double-capped. Another name is soffit. Their flask is made of quartz and has a small size. They give light exclusively in a horizontal position.
The main characteristics of metal halide lamps are conventionally designated by the letters DRI: arc, mercury, iodide lamp. Some types have the letter "Ш" at the end (DRISH), which denotes the spherical shape of the discharge tube. This is followed by the designation of power: 400, 700, 1000, etc. It turns out the following: DRI700.
Principle of operation
The heart of MGL is a quartz flask, which manufacturers began to replace more often with a ceramic one because of the material's resistance to temperature extremes. This flask acts as a burner surrounded by another flask - the outer one.
The burner is filled with inert gases and impurities of metal halides, necessary for the full spectrum of radiation (after all, mercury does not give all colors). When the metal halide lamp is turned off, the chemical constituents are deposited in a thin layer on the burner surface. When it turns on, it takes some time for all the components to warm up. When mercury and other chemical elements evaporate, they emit light. Here the outer bulb plays a very important role - it keeps the high temperature, not allowing the structure to cool down, and thereby prolongs the life of the burner itself.
Metal halide lamps are connected according to the rules, since the principle of operation and the design of the attribute has its own characteristics (it has a voltage dependence). In particular, these products require the inclusion of a current limiting element (ballast).
Application options
Different wattage and wide color range of metal halide lamps make it possible to use them in the following areas:
- filming studios;
- architectural structures;
- car lights;
- installations for lighting public buildings;
- scenes;
- railway stations;
- sports facilities, etc.
Lighting devices of this type can have high power, therefore they find their application in industry and landscape design. Often such attributes are used as street lighting at night in parks, squares, to illuminate buildings, monuments, etc.
In the stadium, metal halide lamps are indispensable tools. Circuses, shopping centers, advertising structures, arenas, office buildings - those structures that require powerful lighting.
Luminaires with MGL are favorable for plants, therefore they can be used in greenhouses and greenhouses. They are also great for aquariums.
Comparison with LED models
In the modern world, metal halide and LED light sources are gradually replacing incandescent lamps from everyday life. These attributes save energy and provide excellent lighting, but there are significant differences between them. To clearly distinguish between them, you should consider the advantages of each of the lighting fixtures.
Advantages of MGL:
- high energy efficiency;
- high light output;
- excellent power;
- uninterrupted operation of the product, regardless of the temperature indoors or outdoors;
- the color rendition is as close as possible to sunlight, therefore, it is comfortable for visual perception;
- small dimensions of products allow you to control its luminous flux.
LED attributes have their own advantages:
- low power consumption;
- lack of ultraviolet radiation;
- long service life;
- these are environmentally friendly models;
- shock resistant;
- instant warm-up.
It is noticeable that both bulbs have a lot of advantages. Therefore, disadvantages play a decisive role:
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MGL:
- high price;
- voltage change affects color rendering;
- long time to warm up;
- harmful due to the content of mercury.
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LEDs:
- an unpleasant glow spectrum for reading literature and small work, but in this case, you should choose the right models;
- high price.
The main preference is given to LED attributes due to their safety and greater energy savings. In addition, they are more suitable for living spaces. Metal halide lamps are indispensable for stages, industrial and public buildings, sports facilities and other similar structures.
How to check if it works?
The performance of these lighting devices is checked simply: the lamp with this lamp is turned on and its functioning is observed. If interruptions are noticed, then the product is defective. The reason may be the wrong connection or the light bulb itself.
You should also check the voltage of the mains: if it does not reach 220 Volts, the MGL is unstable, which means it can light up and go out, not warm up at full power.
If these attributes give poor illumination, you need to check the following:
- serviceability of the cable (it may be broken);
- correct installation of power supply to the track;
- correct connection to the shield.
Since MGL does not start without ballast, which is used as ballast, its serviceability is also checked. Indeed, the evenness of lighting depends on it.
If problems with MGL are found, they can be replaced with LED ones. If metal halide devices have high power, then instead of one such lamp, two LED ones are used.
Shelf life
The lifespan of metal halide lighting attributes depends on several criteria:
- the quality of quartz burners;
- storage conditions of products;
- quality of finishing;
- manufacturer.
Some companies' lamps can last for decades, while others are much shorter, so the brand should also be considered. The main thing is that the products themselves do not leak.
Another important point - creation of the right conditions for storage of MGL. If they are observed, the attributes will be able to last longer.
Examples and variants
Metal halide lamps are rarely or never used in the home due to their mercury content. However, they are excellent lighting fixtures in greenhouses and greenhouses. This is because plants need a special color rendering spectrum: red is needed during flowering and fruit setting, and blue for vegetative growth. However, recently scientists "insist" that such artificial lighting in one tone is stressful for plants, and they need a different spectrum of light flux. This is how greenhouses and greenhouses are illuminated with MGL.
The aquarium is another place for the successful placement of metal halide lighting fixtures. These attributes cannot be replaced with others because of their undeniable advantages specifically for aquariums:
- the required level of illumination, while saving electricity;
- due to the point nature of the source, the light rays reach the very bottom;
- change in the appearance of the aquarium: the picture is embossed and contrasting.
Such lamps look in aquariums as follows.
In sports facilities and on stages, the MGL looks a little differently.
Buildings are illuminated equally skillfully.
For information on how to connect a metal halide lamp, see the next video.