Despite the development of LED technology, metal halide lamps (IPF) continued to hold its market niche for unique characteristics. Their internal structure can vary greatly depending on the intended application.
Therefore, the choice of IPF is necessary to understand in detail the principles of operation and features of these devices.
The content of the article:
- How are metal halide lamps?
- Light emission mechanism
- Construction IPF species
- Technical features lamps
- General operating parameters
- The advantages of metal halide lamps
- The negative side of the device
- Scope fixtures
- How to choose metal halide lamp?
- Useful videos on the topic
How are metal halide lamps?
IPF have a complex internal structure. Externally - is a glass cylinder with a cap, although some models resemble a pear-shaped bulb.
Inside the shell is another working capsule of glass or transparent ceramics, and conductive elements and resistors.
The outer bulb is typically filled with nitrogen, and the inner - an inert gas under pressure, a small amount of mercury and additives of metal halides. This design and determines the name of the product.
As the metal halide used mainly sodium iodide or scandium. They serve for the correction of the light spectrum and affect the scope of the metal halide lamps. In the off-state mercury and additives in the solid state of siege on the glass walls.
Independently when connected to the mains IPF will not turn on. To apply this start-adjusting apparatus (PRA), which provide the necessary inrush current and voltage to effect the onset of thermionic emission in the inner flask.
Light emission mechanism
Turning IPF stepwise. First, due to the inrush current exceeding 10-20 times the working, the inner flask minimum electric discharge occurs in an inert gas environment.
Thereafter, for 3-6 minutes heating occurs mercury and metal halides that evaporate and turn into ionized phase. The current at this time is about 2 times the worker. Ions increase the conductivity of the air mixture and provide gradual nominal lamp output to luminosity.
Due dvuhkolbovogo device in the working capsule supported stably high temperature which prevents the metal vapor deposition on the walls.
After switching off, the IPF must necessarily cool and metallic vapors settle on the walls of the inner core. Only then will restart the lamp.
Such a restriction is a significant disadvantage, so the metal halide lamps used for domestic needs, which often need to switch on / off lighting.
On condensation processes in IPF affects gravity, so many models require a well-defined position in the space.
The principle of operation of discharge lamps difficult, but it allows us to achieve the proper spectrum and strong light. Furthermore, the use of ballast to stabilize the characteristics of the light emitted during vibration power parameters.
Construction IPF species
Metal halide lamps are used for lighting as the corridors and rooms, and large open industrial sites. Therefore, their thickness ranges from 10 to 2000 watts.
Lamps with a high power consumption normally connected to the network 380 and are used only for Industrial facilities. The most popular models have low power 35-250 watts.
Uniform international IPF labeling standards there, but in most cases the letter M stands for "metal halide", and H is informed about the content of mercury in the lamp.
Domestic manufacturers can use their abbreviations: D - arc; And - iodide, R - mercury. After specifying the model usually is the type designation and the cap diameter.
Metal halide lamps have a different structure. The following are embodiments of the classifications of these products depending on their technical parameters:
- By targeting type: vertical (BUD), horizontal (BH), universal (U).
- On the size of the bulb: BT - a bulb-tube, R - reflex, E or ED - ellipsoidal, ET - ellipsoidal, tubular, T - tube, PAR - parabolic.
- The color of light: white, yellow, purple, green and others.
- By type: wedge base - with flexible current leads, single-ended, double-ended.
External performance metal halide lamp has little effect on its efficiency, because a direct radiating element is located in the protected inner flask. It determines the characteristics of the emitted light.
Technical features lamps
Technical characteristics of IPF are quite diverse. They depend on the materials used in the production and electrical parameters of the metal halide lamps. These devices are marked advantages and disadvantages that are worth to know when buying.
General operating parameters
Metal halide lamps are nepriveredlivyh to ambient and continuity. They can burn for weeks in freezing temperatures without suffering congestion.
The main parameters that characterize the IPF are:
- color rendering index (CRI);
- operating life;
- light flow;
- view of the cap;
- Colour temperature;
- ratio of luminous flux to an electrical power;
- working temperature.
The color rendering index is considered to be an important characteristic of IPF. CRI characterized by the presence in the emitted spectrum at different wavelengths and intensity uniformity.
This is measured as a percentage of similarity with natural daylight. Modern IPF color rendering index of 85-95%, and the majority of household LED-equipment - 70-85%.
In some lamps intentionally distort the coloring to give the light of the required properties. For example, sodium IPF used for the growth of plants, are only 50-60% CRI.
The effectiveness of the lamp does not fall from it, just most of the energy it emits in a given wavelength range. To give light yellow shade is sodium halides, green - thallium, blue - indium.
With regards to performance, the metal halide lamps are not lagging behind LEDs. This indicator both mid-range devices 100-120 lm / W.
IPF color temperature may range from 2500-20000 ° K. When the fall in the voltage is changed upward and the light becomes colder.
Prolonged exceeding the target of 240 V lamp may simply explode due to overheating in the gas mixture inside the flask.
An important quality of the IPF is a lumen throughout the period of operation, which is of 6-15 million hours. If the LED efficiency after 10,000 hours of operation drops by about 50%, then the metal halide lamps - only 2-20%.
The remaining options depend on the specific model of the luminaire and are not specific.
The advantages of metal halide lamps
The modern market based lighting slowly shrinks due to the onset of the LED. However, the unique properties of IPF for at least another few decades will be in demand by consumers.
The main advantage of these lamps is:
- Excellent energy efficiency. Each lamp watts consumed energy outputs over 100 lumens of light.
- A high level of color rendition index.
- Perfected the production technology that minimizes damage to the internal components of the lamp.
- A wide range of capacities.
- Long service life.
- Resistance to high temperatures due to the absence of electronic components inside the lamp.
Metal halide lamps advantageously compete with LED and fluorescent. All three technologies are actively developing, and therefore from the IPF can expect further improvement.
The negative side of the device
The absence of metal halide lamps in the domestic sphere shows that they have not only positive but also negative qualities.
The main disadvantage of IPF are:
- The cost is several times that of the LED devices.
- No possibility of dimming.
- The need for cooling for 5-10 minutes before reclosing.
- The presence of an external ballast, which requires additional installation space.
- A gradual increase in the color temperature for long term use.
- EXPLOSION surges.
- Sensitivity to spatial arrangement.
- Absolute non-repairable.
- The need for special utilization of the content of toxic substances.
- Time need to enter the current luminous flux after power-up.
Thus, the disadvantages they have even more than the pros. This narrows the scope of the IPF to industrial and public buildings and grounds, which need continuous and high-quality lighting.
Using metallogalogenok home is not only impractical economically, but also dangerous because of the mercury content. The bulb may shatter, and the room filled with toxic vapors.
Because of the insecurity, mainly use metal halide lamps only demand primarily for residential spaces:
- Filming studio, photo salons.
- Car lights.
- Architectural structures.
- Public buildings, shopping mall.
- Industrial halls.
- Under construction.
- Street lighting.
- Sports objects.
- Greenhouse complexes and greenhouses.
- Night lighting of country houses.
Most people are not faced with the purchase IPF also because these devices are rarely sold in small DIY stores. They acquire businesses and entrepreneurs mostly from specialized companies.
How to choose metal halide lamp?
Specificity applications based bulbs forcing careful approach to the choice of their characteristics. This product is, of course, you can always swap, but it is better to acquire a suitable model.
The main recommendations of the acquisition metallogalogenok following:
- Carefully read the labels on the packaging, which can inform the restriction of the use of IPF in certain circumstances.
- Claimed operating position the product must comply with the lamp position, for which it is intended. The smallest share in vertically oriented models.
- The diameter of the base must fit the lamp holder.
- Starter housing must be made of metal with sufficient ventilation holes. Indeed, depending on the model, ballast consumes 10-20% of the lamp power.
- The starting device is designed for a specific voltage and current, so when replacing the lamp, these factors should be taken into account.
- In some cases, critically important fast ignition IPF, so the time of its release to the nominal luminosity is necessary to read the manual beforehand.
If the metal halide lamp is purchased to replace the failed, it is possible to take with you to the store for example a broken model.
IPF are expensive, so it is important to save when buying all receipts and invoices, so you can use later warranty rights.
Useful videos on the topic
Overview of the characteristics of metal halide lamps:
Check the operation of the metal halide spotlights:
Connecting metal halide lamps:
Metal halide lamps shall continue to apply in many areas, despite a number of structural weaknesses. The diverse range of radiation allows to pick them under the different needs of business. Therefore, the IPF will long remain competitive in the niche of industrial lighting.