Metal halide lamps. Types and device. Work and application. What are the lamps for lamps MGL and their connection diagram Service life MGL

A metal halide lamp (MHL) is a high-pressure gas-discharge light source. During the operation of the lamp, an arc discharge occurs in mercury vapor in an inert argon environment, while the spectrum is determined by special radiating additives - the halides of some metals.

Halides such as scandium and sodium iodides help the discharge to exist and do not react with the quartz glass of the bulb. While the lamp is cold, the halides are condensed in the form of a thin film on the walls of the discharge tube (burner), but as the temperature rises, the halides evaporate, mix with mercury vapor in the discharge area, and decompose into ions. As a result, excited ionized atoms.

The burner is made of quartz glass or ceramics, and the outer protective flask is made of borosilicate glass (in addition to the protective mechanical function, the flask cuts off ultraviolet from the spectrum).

In a number of industrial types of MHL, there is no external flask; in this case, ozone-free quartz glass is used to make the base. It prevents the increased formation of ozone and reduces the risk of mercury resonance (185 nm) in the lamp.

The principle of operation of a metal halide lamp in 1911 was described and proposed by the American electrical engineer Charles Steinmetz. The lamp start is carried out, which at the beginning ensures the ignition of the arc, and then maintains the operation of the lamp.

The starting device can be directly a choke or an auxiliary high-voltage transformer. Then, when the discharge is ignited, the nominal voltage is maintained on the electrodes, and the lamp emits visible light.

Today, MGL-type lamps are produced in a wide range of powers. For outdoor lighting, lamps are used for 70, 150, 250, 400, 1000, 2000 watts, single-ended or double-ended, with pin or soffit bases. They are designated as SE or DE - single-ended (single-ended) and double-ended (double-ended).

Since gravity acts on the arc plasma, the working position of the lamp must be strictly defined. So, metal halide lamps are horizontal orientation, vertical orientation and universal. Markings respectively: BH, BUD, U - base horizontal, base up / down, and universal. If the lamp is not used in the proper working position, its life will be shortened and its performance will be poor.

According to the American National Standards Institute ANSI, metal halide lamps are marked starting with the letter "M", followed by a numerical code with the electrical characteristics of the lamp and with a designation of the type of ballast. The numbers are followed by two letters indicating the size and shape of the flask and its coating. Further, each manufacturer in its own way indicates the power of the lamp and the color of its glow. The European marking differs slightly from ANSI.

The bulb of a metal halide lamp is marked with letters indicating its shape and numbers indicating the maximum diameter of the bulb. Letters BT (Bulbous Tubular) - bulbous tubular, E or ED (Ellipsoidal) - ellipsoidal, ET (Ellipsoidal Tubular) - ellipsoidal tubular, PAR (Parabolic) - parabolic, R (Reflector) - reflex, T (Tubular) - tubular.

For example, the Lisma DRI 250-7 lamp is marked with respect to the E90 bulb - an ellipsoidal shape, a diameter of about 90 mm. Base type E40, power 250 watts. As you can see, the designation here is different. In general, the range of metal halide lamps is very wide.

Characteristics of metal halide lamps

The color of the glow of a metal halide lamp and the color temperature are mainly related to the type of halogen used. Sodium compounds give a yellow tint, thallium - green, indium - blue. Initially, metal halide lamps were used where light was required close to natural, white, without an admixture of blue.

It is possible to obtain pure daylight from metal halide lamps with a color rendering index above 90. In principle, any color temperature from 2500 to 20000 K is achievable.

Special types of MGL are used in greenhouses and greenhouses for plants, in aquariums for animals, where a special spectrum is required. At the same time, when choosing a lamp, it is important to remember that the color characteristics in reality will initially differ from those indicated in the specification, since the indicated characteristics refer to a lamp that has already worked for 100 hours, that is, at first they will differ slightly.

The greatest discrepancy in characteristics is observed in metal halide lamps with preheating, in which the difference in color temperature reaches 300 K. In lamps with a pulse start, the discrepancy is smaller - from 100 to 200 K.

A long-term deviation of the supply voltage from the nominal value can lead to a change in the color of the light and the luminous flux. A sharp fluctuation in the mains voltage above +/-10% can cause the lamps to turn off.

If the mains power jumps, the color temperature will also float - if the voltage is less than the nominal, then the light will be colder, since the additives responsible for the color are not ionized in sufficient quantities.

If the voltage turns out to be more than the nominal value, the color will turn out to be warmer, however, a prolonged excess of voltage threatens to explode the bulb due to the increased pressure in it. It is best to provide for the stabilization of the supply voltage.

Advantages of metal halide lamps

The spectral and electrical characteristics of metal halide lamps can vary widely, and the market is huge. The quality of light and high luminous efficiency explain the widespread use of MHL today in various lighting installations and lighting devices.

The lamps are compact, powerful, efficient as a light source, and are today a promising replacement for traditional arc mercury fluorescent lamps (XRL) and high pressure sodium lamps (HPLS), thanks to a softer and safer spectrum for humans.

The luminous flux of MGL lamps is up to 4 times higher than that of incandescent lamps, and the light output is on average 80-100 Lm / W. Color temperatures of 6400 K (cold light), 4200 K (natural light) or 2700 K (warm light) are easily achievable with a color rendering of around 90-95% - this is a very good color rendering for a lamp that is 8 times more efficient than an incandescent lamp.

Power can vary from 20 W to 3500 W from a single source, and uninterrupted operation does not depend on the ambient temperature and its fluctuations if the lamp has already been lit. The service life of the MGL lamp is calculated on average for 10,000 hours of continuous operation.

MGL lamps are used today very widely. Film lighting, outdoor lighting in architecture, decorative lighting, stage and studio lighting, etc. Metal halide lamps are extremely popular in industrial lighting in workshops, in spotlights in open spaces of railway stations, in quarries, on construction sites, at sports facilities, etc.

Lighting of public and industrial buildings, special lighting for plants and animals, as a source of near ultraviolet. Finally, street lighting, illumination of landscapes and shop windows, for creating lighting effects in design and advertising, in shopping centers ... - metal halide lamps have taken their rightful place everywhere.

One of the types of gas discharge lamps are metal halide lamps. They have the same glow principle that is used in every gas discharge lamp. The principle is that they have an electric arc discharge between the electrodes in the lamp, which is filled with mercury vapor and other chemical elements. The main difference from simple discharge lamps will be that compounds such as metal iodides were included in mercury vapor. These compounds are considered halogen. This contributes to the fact that evaporation from the electrodes of the tungsten lamp does not settle on the inner walls of the bulb.

During operation of a metal halide lamp, tungsten vapors interact with halogen compounds, thereby forming a tungsten iodide mixture. And when the lamp is turned off, these particles return to the electrodes.

Therefore, lamp electrodes have high protection against destruction, and the bulb remains transparent for a long time. Plus, in these lamps, metal iodides are used in order to improve the quality of the luminous flux, as the spectral characteristic of the arc discharge changes. Now it is the most economical and practical light source. Due to the addition of a tungsten-halogen cycle, the service life of the lamps has increased several times.

Where applicable

MGLs produce brighter, higher quality light. They are used both for general street lighting, site lighting, billboard lighting, and for lighting indoor industrial spaces. Due to its wide spectrum of luminescence, in some cases they are used for home lighting.

It can also be found in winter greenhouses and greenhouses. This is due to the suitable light temperature for plant life.
MGL lamps are in particular demand among aquarium holders. Especially those who do this in large volumes for sale. This is due to the fact that metal halide aquarium lamps are able to reproduce the correct spectrum for fish life.

Design

In its structure, haze does not differ much from mercury arc light sources. It also uses a burner made of ceramic or quartz. The flask plays a big role in ensuring the right temperature, reduces heat loss and cuts off ultraviolet radiation. The flask is made of borosilicate glass, which has increased strength and heat resistance. You should be aware that industrial models do not provide for an external flask; ozone-free quartz glass is used there.

Due to the fact that modern modifications are used in the lamp, metal halide lamps do not imply incandescent filaments, which ensures longer service life. There is also an easier start, due to the use of ignition electrodes.

Due to the fact that the flows of halide during the passage of the discharge depend on gravity, the lamp must be in the required position during operation. Lamps with two bases can only be operated in a horizontal position. Models with one base, for the most part, work with a vertical installation. There are separate models that are suitable for working in any position. Horizontal models are marked with the letters "BH" and vertical ones with "BUD". For any positions - "universal".

MGL classification

Initially, they are divided into:

single-ended;
Double-ended. Otherwise, double-ended ones are called soffit;
Without plinth.

Plinth type:

RX7s;
G8.5;

This light source has 3 emission spectra:

Warm spectrum, with a light temperature of 2700K;
Neutral spectrum, with a light temperature of 4200K;
Cold spectrum, with a light temperature of 6400K.

By marking:

D - arc;
P - mercury;
Y - iodide.

By power.

220V - 20, 35, 50, 70, 150, 250, 400, 700, 1000 W;
380V - over 2000 watts.

Types of luminaires may differ according to the type of installation:

Recessed - when the luminaire can be fixed in suspended ceiling structures;
Consignment note - when the device is attached to a wall or ceiling;
Track - when the lamp has a special reflector that can accentuate the glow radius;
Suspended - when the luminaire can be suspended from the ceiling or ceiling lintels.

Advantages and disadvantages

As with all types of lamps, there are both advantages and disadvantages. Among the advantages can be noted:

The luminous flux of MHL is 4 times higher than that of incandescent lamps, and the efficiency is 8 times;
Not whimsical to environmental conditions;
Compact and energy saving;
Service life about 15,000 hours;
There is a wide choice of light temperature.

Among the shortcomings can be identified:

Strong heating of the flask, which reduces fire safety;
Sensitive to voltage drops;
Requires time to reach full capacity;
Cannot be turned on within 10 minutes after turning off if there is no ballast;
Sensitive to working position;
Requires special disposal.

MGL connection

Since this light source cannot be connected directly to the network, there are certain auxiliary devices that allow you to start. Since the burner cannot ignite itself, it needs a high-quality high-voltage discharge. For this, a ballast control gear is provided, which is otherwise called ballast. They are electromagnetic and electronic. It is best to choose electronic ballasts, as they can significantly extend the service life and provide an even glow at start-up. The advantage is ballasts that have a built-in IZU, which can not only ignite the burner, but also limit the current. Another advantage is their size, as they are more compact and lighter. To extend the service life and save electricity, it will not be superfluous to install a capacitor.

How to choose an MGL lamp

To select, you must first determine the required power. For small warehouses, 150-250W is enough, for stadiums you need to use light sources of 1KW and higher. Next, you need to select the number of socles, while remembering that in a vertical position this light source shines a little worse and the service life will be shorter. Universal models fail faster and lose their light output earlier.

Some models require ballasts of certain models. For example, a European lamp may not work with an American ballast and vice versa. European products require ballasts with the HQI mark.

Outcome

Since it makes little sense to use MGL lighting for domestic purposes, you need to clearly understand its purpose, since these are more like industrial lamps. Due to the time that must elapse before restarting, they should not be connected in places with power outages. They can carry a fire hazard, therefore it is not recommended to use them near flammable objects. To start MGL lamps, you need to connect additional elements, which also need to be placed in the lamp.

Video about MGL

The main disadvantages of conventional light sources are huge energy losses and fragility. The use of more advanced technology can triple the life of metal halide lamps and cut power consumption in half. Their declared characteristics remain unchanged. A decrease in the radiation intensity by 1-2% for metal halide lamps (MHL) is observed only towards the end of the service life.

All light sources of this type are classified as gas-discharge lamps. The main part of them is a burner made of quartz glass or ceramics. Heat-resistant materials are used in the production process of devices, the flask is made of borosilicate glass with a slight coefficient of thermal expansion. The MGL model range is very diverse, manufacturers constantly replenish it with new products for specialized applications.

Specifications for metal halide lamps

Photo	vendor code	Name	Power, W	Package
		FOTON MH 400W E40 WHITE (BT) 5200K 28000lm 10000h d62 l283 - bulb (050)
		FOTON MH 250W E40 WHITE 5200K 20800lm 10000h d46 l256 - bulb (046)
		OSRAM HQI-TS 150W/GREEN EXC RX7S - color lamp
		OSRAM HQI-TS 150W/MAGENTA RX7S - color lamp
		HCI - PAR20 35W/830 WDL PB SP 10D E27 (protective glass frosted) OSRAM - bulb
		FOTON MH 250W Е40 BLUE - lamp (044)
		HCI TT 100W/830 WDL SUPER 4Y WDL PB E40 OSRAM - lamp
		FOTON MH 400W E40 BLUE (BT) - lamp (048)
		HCI TT 150W/830 WDL PB E40 OSRAM lamp
		FOTON MH 400W E40 RED (BT) - lamp (049)
		Lamp (051) FOTON MH DRI 70W RX7s 5200K WHITE
		Lamp DRI (046) FOTON MH DRI 250W E40 WHITE 5200K 20800lm 10000h d46 l256 -
		HCI-TT 150W/830 WDL PB E40 OSRAM lamp
		Bulb E27 OSRAM HCI-ET 50W/830 SUPER 4Y
		lamp (057)FOTON MH 150W RX7s-24 GREEN
		Lamp (058)FOTON MH 150W RX7s-24
		Lamp (047) FOTON MH 400W E40 (BT)
		Lamp OSRAM HCI - PAR30 35W/942 NDL PB SP 10D E27 (protective glass frosted)
		Lamp OSRAM HCI - PAR30 70W/930 WDL PB FL 30D E27 (4008321964595new)
		Lamp HCI-TM 400W/930 WDL PB G22

Advantages and disadvantages of metal halide lamps

MGL has many advantages:

energy efficiency;
high power;
significant light output: 80–170 lumens/Watt;
unpretentiousness to operating conditions, in particular, to temperature changes;
the emitted light is as close as possible to the sun, as a result it does not irritate the eyes;
compactness.

However, metal halide lamps are quite expensive, they change the color of the radiation when the voltage drops in the mains. In addition, it takes time for the MGL to reach the operating mode.

But these shortcomings are not important for the conditions in which metal halide lamps are usually operated. For outdoor lighting, the power of the source and its energy-saving qualities are the most significant. This is what metal halide lamps provide.

MGL allows you to save energy at high radiation brightness. Due to the miniaturization of the glass bulb, such lamps can be inserted into compact equipment, powerful light sources can be used for directional projector radiation.

A unique characteristic of metal halide lamps is their unsurpassed color reproduction, which is the closest match to sunlight. That is why MGL is preferred for lighting trading floors and shop windows. Once turned on, metal halide lamps quickly reach their stated power level. The emitted white color is pleasing to the eye, while cool and blue shades are in demand in the industry.

For quite a long time, metal halide lamps (MHL) have been widely used in a variety of lighting technology. They are compact, economical, and their power can reach 20 kW. At the same time, lighting devices with MGL have excellent color rendering and can even shine in different colors. How is such a lamp arranged and what are its main characteristics? The article will answer these questions, and at the same time tell you how to connect a metal halide device on your own.

MGL lamp design

The metal halide lamp belongs to gas-discharge devices. It works using the principle of ionization of mercury vapor mixed with halides - compounds of halogens with other chemical elements.

Structurally, a metal halide lighting device is a flask made of refractory quartz or ceramic glass with soldered electrodes. The flask is filled with inert gases, to which metallic mercury and halides of certain metals are added. It is they who expand and equalize the visible radiation spectrum of the device, and also allow you to change the color temperature and color of the lamp glow.

This flask, which plays the role of a burner, is placed in another, external, filled with an inert gas or evacuated. Its task is to protect the burner from mechanical and thermal influences and absorb ultraviolet radiation, which is present in the radiation spectrum of mercury and, when interacting with the surrounding air, forms ozone that is poisonous to humans. Additionally, the external flask reduces heat loss, significantly increasing the efficiency and service life of the device.

Construction of a metal halide lamp

Expert opinion

Alexey Bartosh

Ask an expert

There are also single-bulb lamps, but in this case, ozone-free quartz glass is used to make the burner, which cuts off hard ultraviolet radiation. This, of course, does not apply to special metal halide devices designed specifically to produce hard UV radiation.

Single-bulb metal halide lamp for industrial use with a power of 2 kW

For connection to the mains, the appliance is equipped with the following types of plinth or plinths:

E27, E40 (Edison base);
RX7s (soffit double-ended version);
G8.5, E12 (pin).

Devices with a power of 2 kW and above have flexible leads with screw terminals instead of socles.

Metal halide illuminators with various types of plinths

Principle of operation

In a cold state, mercury vapor and halides settle on the walls of the burner, and the gas gap inside it has a high resistance. Therefore, to start the lamp after applying the supply voltage to the electrodes, it is necessary to apply a high-voltage pulse to them. To do this, use a pulse ignition device - IZU.

Pulse ignitor for metal halide lamps

Thanks to him, a glow discharge appears in the burner, which heats up the mercury and halides. As a result, the latter evaporate. The pressure in the flask increases, and the resistance of the gas gap decreases. The glow discharge gradually turns into an arc discharge, causing mercury ions to emit visible light - the lamp flares up. The time for the device to enter the operating mode takes an average of 10-15 minutes.

At the same time, halogens come into play - they also begin to emit in a certain spectrum, leveling and supplementing the radiation spectrum of mercury. As a result, a metal halide source can emit light not only of different color temperatures from warm reddish to cold blue, but also of different shades: green, red, blue, etc. Everything will depend on the composition and amount of halides. This is the main feature of the metal halide lamp: its color rendering is exceptionally high and can reach 95.

The emission spectrum of a metal halide lamp is much smoother and wider than the spectra of any other gas-discharge light sources.

Expert opinion

Alexey Bartosh

Specialist in the repair, maintenance of electrical equipment and industrial electronics.

Ask an expert

When buying a metal halide illuminator, pay attention not only to its power and base, but also to the color temperature and, moreover, color. Otherwise, you run the risk of highlighting the object with shades of blue or red instead of the intended lighting with daylight, or vice versa.

In order to prevent the discharge in the burner from turning into an uncontrolled arc when the lamp is heated, the current through the device is limited by special ballasts: electromagnetic (choke) or electronic. The former are called EMCG (electromagnetic ballast), the latter - electronic ballast (electronic ballast). Chokes are much cheaper than electronic analogues, but the latter increase the efficiency and reliability of the lamp, and, most importantly, eliminate the flickering of a lamp with a doubled mains frequency.

Electromagnetic and electronic ballasts for metal halide lamps

Types and characteristics

Unfortunately, there is no single marking for metal halide lamps in the world; each manufacturer can mark the device at his discretion. Nevertheless, some names of the MGL are well-established, and one can orient oneself among them. In Russia, metal halide lamps are usually marked with the letters DRI (Sh) followed by an indication of the power in watts, where:

D - arc;
P - mercury;
I - iodide;
Ш - spherical shape of the burner.

Lamp DRISH-450 - arc mercury iodide with a ball-shaped burner with a power of 450 W

The operating voltage on the bulbs may not be indicated. By default, for devices with a power of up to 2,000 W, it is 220 V, for devices of 2,000 W and above - 380 V.

As for foreign manufacturers, they have the most common designation for metal halide lamps - HMI (English metal halide lamp) or HM followed by an indication of power.

For other design characteristics, the following designations are accepted:

SE - single-ended.
DE - two-socle (soffit).
BH - working position horizontal.
BUD - vertical working position.
U - any working position.
T - cylindrical flask.
E - ellipsoidal flask.
ET - ellipsoid-tubular flask.
VT - bulb-shaped-tubular flask.
R - reflex flask.
P - parabolic bulb.

Additionally, a metal halide lamp can have its color temperature in Kelvin.

400 W cylindrical metal halide lamp

Expert opinion

Alexey Bartosh

Specialist in the repair, maintenance of electrical equipment and industrial electronics.

Ask an expert

The marking on the lamp itself may be incomplete, so when buying, carefully study the packaging or accompanying documentation, if any. Pay special attention to the working position of the device: a lamp with a horizontal working position will not work vertically for a long time, and vice versa.

Scope of application

The scope of lamps with MGL determined their three main differences from other light sources:

Excellent color rendering.
High light output.
Compactness.

Due to the above properties, metal halide illuminators are widely used in film and photography, stage lighting, lighting and lighting of mass cultural events, including outdoor areas.

High power with small dimensions made it possible to use metal halide light sources in searchlights and flood-type illuminators of open objects: railway stations, airports, stadiums. You can find lamps of this type in architectural lighting and in the lighting systems of industrial and public buildings, as well as in the headlights of various vehicles: from cars to aircraft. In everyday life, unfortunately, metal halide lamps did not take root due to the long warm-up and the impossibility of a quick restart.

Examples of using metal halide illuminators

There is another area of application for metal halide lamps. By selecting the composition and amount of halides, it is possible to create a spectrum necessary for the vital activity of various plants. It is these lamps that are successfully used in greenhouses and in.

Using metal halide luminaires to illuminate plants and aquariums

Advantages and disadvantages

The most important advantage of a metal halide lamp is a wide and uniform emission spectrum. Its light almost completely corresponds to the sun, and the color rendition reaches 95%. does not provide any source of artificial light that exists today, including LED lamps.

The second important advantage is high energy efficiency. A metal halide lamp of even low power is capable of producing a luminous flux of up to 70 lm per watt of power consumption. And starting from a kilowatt and above, the light output of the device can reach 95 lm / W. This is almost the same as for LED lamps of real cost (diodes with a light output of 120 - 150 lm / W exist, but their production is unreasonably expensive).

Expert opinion

Alexey Bartosh

Specialist in the repair, maintenance of electrical equipment and industrial electronics.

Ask an expert

Among other things, it is worth mentioning the color temperature. It, like the color of the glow, with the help of certain additives of halides, can vary quite widely.

Let's add to the advantages a relatively low cost (tens of times cheaper than LED sources of the same power) and a service life, which, depending on the power, ranges from 10,000 to 15,000 hours. For comparison: the average life of sodium lamps is 10,000-20,000 hours, and LEDs, whose MTBF is considered fantastic, are 15,000-30,000 hours.

Metal halide light sources have the following disadvantages:

High operating temperature. Like any other arc light source, metal halide gets very hot. The temperature of the burner can reach 1200, and the outer flask (if provided by the design) - 300 degrees Celsius. This, of course, requires the adoption of special security measures.
Long ramp-up time. After switching on, it takes 10-15 minutes for the device to enter the operating mode - it flares up. Also, once turned off, the lamp will not start until it cools down. This drawback is a constraint for the use of metal halide lamps in everyday life, where it is quite difficult to wait 10-30 minutes until the lamp starts to shine.
Contains toxic substances. The burner of a metal halide lamp is filled with metallic mercury, so it cannot be taken and thrown into the trash. MGL must be disposed of at special points.
The need for additional equipment. In order to run a metal halide lamp, you need a ballast and IZU, which are often larger in size than the lamp itself and, of course, cost a lot of money.

Wiring diagram

As I said above, a pulse igniter is required to start a metal halide lamp, and a ballast (ballast) is required to limit the current through it. The first is connected in parallel with the lamp, the second - in series with it.

Scheme for switching on metal halide lamps with two- and three-pin IZU

Usually, such a scheme is applied directly to the ballast body and IZU, so it is not difficult to assemble a metal halide lamp with your own hands. To do this, a conventional screwdriver and a voltage indicator are enough to determine the zero and phase in the network.

The only thing to consider is that the lamp and ballast heat up quite strongly: the first is up to 300, the second is up to 100-120 degrees. Therefore, when designing a luminaire, it is necessary to provide for ventilation of the equipment (usually just ventilation holes are enough), and the lantern itself should be placed away from flammable objects.

Operation features

When using an electromagnetic ballast (choke), in order to reduce reactive losses and slightly increase the efficiency, it is desirable to install a compensation capacitor in parallel with the luminaire, indicated in the diagram by a dash-dotted line. Its operating voltage must be at least 400 V (for 380 V lamps - 600 V), and it must be non-polar paper. The capacitance of the capacitor is selected based on the power of the lamp. For DRI-250, for example, 35 uF is enough, for DRI-400, the capacitance can be increased to 45 uF.

For high-quality and long-term operation of the lamp, the ballast power must correspond to the lamp power. The IZU is chosen so that the lamp power falls within the range indicated on its body.

And one more piece of advice. Install the DRI lamp only with cotton gloves or a clean cloth. The fact is that the outer flask of the device heats up to 300 degrees, and if the device is single-flask, then up to 1200. The “fingers” that you leave on the flask will burn out and form a layer of soot that does not conduct heat well. As a result, local overheating will occur, and the glass will simply burst. If you or someone else has already "captured" the light bulb, wipe it with a cloth soaked in alcohol.

This lamp can be thrown away due to a crack that appeared as a result of local overheating of dirty glass.

So we figured out the metal halide lamps. If you have read the article to the end, now you know how it works, how it turns on and how it differs from other gas-discharge light sources.

Despite the development of LED technology, metal halide lamps (MHL) continue to hold their market niche due to their unique characteristics. Their internal structure can vary greatly depending on the intended application. It is worth familiarizing yourself with the characteristic constructive types. Do you agree?

We will help you understand the principles of operation and features of the MGL device. In the article we have proposed, constructive varieties are given, the scope is indicated. Those who wish to purchase such a light bulb will find valuable recommendations for choosing from us.

MGLs have a complex internal structure. Outwardly, it is a glass cylinder with a base, although some models look like a pear-shaped incandescent lamp.

Inside the shell is another working capsule made of glass or transparent ceramics, as well as conductive elements and resistors.

The ratio of power and volume of MGL is limited by the ability of the outer shell to remove excess heat, because the lamp can burn out from overheating

The outer flask is usually filled with nitrogen, while the inner flask is filled with pressurized inert gas, a small amount of mercury, and metal halide additives. This design determines the name of the product.

As metal halides, sodium or scandium iodide is mainly used. They serve to correct the light spectrum and affect the scope of metal halide lamps. In the off state, mercury and additives are in a solid deposited state on the glass walls.

Independently when connected to the electrical network, the MGL will not turn on. To do this, start-adjusting devices (ballasts) are used, which provide the necessary starting current and voltage until the effect of thermionic emission appears in the inner flask.

Mechanism of light emission

The inclusion of MGL occurs in stages. Initially, due to the starting current, which is 10-20 times higher than the operating current, a minimum electric discharge occurs in the inner bulb in an inert gas environment.

Due to insecurity, the use of metal halide lamps is mainly in demand only mainly for non-residential spaces:

Film studios, photo studios.
Car lights.
Architectural buildings.
Public buildings, shopping malls.
Industrial shops.
Objects under construction.
Street lighting.
Sports objects.
Park areas.
Greenhouse complexes, greenhouses.
Night illumination of country houses.

Most people are not faced with buying MHL also because these devices are rarely sold in small hardware stores. They are purchased mainly by enterprises and entrepreneurs from specialized companies.

How to choose a metal halide lamp?

The specificity of the fields of application forces a careful approach to the choice of their characteristics. The goods, of course, can always be exchanged, but it is better to immediately purchase a suitable model.

Starting devices often come with lamps, because the service life of the MGL largely depends on their compatibility.

Carefully read the inscriptions on the packaging, which may inform about the restriction of the use of MGL in certain circumstances.
The declared working position of the product must correspond to the position of the luminaire for which it is intended. The smallest resource for vertically oriented models.
The diameter of the base must fit the lamp socket.
The body of the starter must be made of metal with a sufficient number of ventilation holes. Indeed, depending on the model, the ballast consumes 10-20% of the lamp power.
The starting device is designed for a certain voltage and current, so these factors must be taken into account when replacing the lamp.
In a number of cases, the rapid ignition of the MGL is critically important, so it is necessary to read the instructions in advance about the time it takes to reach the nominal luminosity.

If a metal halide lamp is purchased to replace a failed one, then you can take the broken model with you to the store for example.

MGLs are expensive, so it is important to keep all receipts and invoices when buying so that you can use warranty rights later.

Comparing metal halide appliances with halogen bulbs will help information on the analysis of the characteristics of the G4 model.

Conclusions and useful video on the topic

Video #1 Overview of characteristics of metal halide luminaires:

Video #2 Checking the operation of a metal halide spotlight:

Video #3 Connecting a metal halide lamp:

Metal halide luminaires continue to be used in many areas despite a number of design flaws. A diverse spectrum of radiation allows you to select them for various needs of economic activity. Therefore, MGLs will remain competitive in the industrial lighting niche for a long time to come.

Please write comments in the block below, ask questions, post photos on the topic of the article. Share your own guidelines for choosing a metal halide light bulb. Tell us why you chose this device.