Recently, the market for lighting devices has become very extensive. Now you can choose lighting equipment for absolutely any purpose. Discharge lamps are one of the most modern devices. They are light bulbs, the light in which arises as a result of electric gas in metal vapors or a special gas mixture.
Content
- Description and varieties
- Advantages
- Functioning principle
- Selection recommendations
Description and varieties
A gas discharge lamp (GRL) is a type of illuminator, the light emission of which occurs during the formation electric discharge in gas connections. In fact, the electric arc is the emitter. The color of the luminous flux depends on the composition of the vapor or gas. In addition, the composition also affects the power of the emitted light flux.
The design of the gas discharge type lamp includes a ceramic, metal or glass bulb. It can take different forms:
- cylindrical;
- arc.
In a cone, besides chemical substances, there are electrodes forming the discharge. The container inside which all working processes take place is called a burner. The electrical discharge generated by the electrodes inside causes the gas compounds to glow.
The service life of various types of discharge lamps varies from three to twenty thousand hours. continuous work. With regard to color rendering, this indicator is at a fairly high level.
Advantages
Discharge lamps are very popular today and are used in various fields of activity. This is due to the following advantages:
- high level of light output;
- compact dimensions;
- resistance to external changes (therefore they are often used on the streets);
- normal functioning at "sub-zero" temperatures;
- profitability;
- durability.
The high degree of light output allows very widely use GRL in equipment for lighting various public events. Resistance to temperature extremes allows the use of gas-discharge lamps outdoors at any time of the year and under any climatic conditions.
Functioning principle
The most important elements of GRL are electrodes. They placed inside transparent cones, the shape of which is different. This vessel is filled with a gas mixture under pressure. In addition to the gaseous substance, elements of metal alloys with vapor pressure (sodium and mercury) are placed in the flask. The evaporation of such metals causes the emission of a light flux in the visible range.
Between individual electrodes a vacuum is formed as a result, the substance filling the cone begins to emit light. Brightness is in direct proportion to the pressure and the quality of the filler material. The miniature size also contributes to an increase in the intensity of light flux. In addition, the composition of the gas determines how high the applied voltage must be.
It should be noted that lights up gas discharge lamp not instantly. The structure heats up gradually, and as it heats up, the brightness of the luminous flux also increases. This is due to combustion inside the flask. The light reaction lasts about two minutes, during which the substances inside the container completely evaporate. Today, some manufacturers accelerate the ignition of the GRL by increasing the number of electrodes inside.
Selection recommendations
Before purchasing this variety, you should consider the main types of this type of product on the market.
All gas discharge lamps can be divided into four main groups:
- metal halide;
- high pressure sodium lamps;
- high pressure mercury lamps;
- low pressure sodium lamps.
The most popular and high quality are considered metal halide bulbs. They contain mercury and various metallic impurities. The electrical discharge in such devices is obtained due to the increased pressure. The service life of such devices reaches 16 thousand hours.
Sodium type lamp characterized by a higher light output. Moreover, it is more durable. It can be used to create warm and yellowish lighting. In the event that the composition contains xenon, then the shade of the light flux will be completely white. The sodium illuminator is mercury free and is considered a very economical type of lighting.
Mercury GRL, with its miniature dimensions, forms a very bright stream of light. The role of the gas mixture is assigned to mercury vapors, which are capable of creating an electric discharge even under low pressure conditions. The bulb of mercury lamps is covered special component - a phosphor. It allows you to increase the light output. The build quality level also determines the life of the product. It is better to give preference to models equipped with dense material (glass) and expensive electrodes. In this case, there will be no problems with lighting.
