In the process of creating fixtures for lighting, mankind has stepped far forward. If we recall our grandmothers who had dinner with a kerosene burner or an ordinary torch, then modern lighting devices are simply surprising. The developers had the task to come up with the most powerful light sources that will work at large temperature fluctuations, cover large areas and perform a number of other functions. The result of all became the DRI lamp. This funny abbreviation has a fairly simple decoding: "mercury arc with iodides." They can work in large industrial areas, in warehouses, trade and exhibition halls, providing absolutely accurate color reproduction.
Design
Regardless of the power of the device, they all have the same structure. Such a device consists of a glass flask coated with a thin layer of a phosphor, a quartz or ceramic burner, filled with vapors of mercury and inert gases that are in the flask, with the addition of metal halides.
Principle of operation
Various iodide mixtures are used to fill the DRI lamp, for example, thulium, cesium, holmium, sodium. They enter the device in the form of salts, which evaporate quite easily. If you choose the right combination of these substances, you get a continuous spectrum of radiation, which meets the high requirements of color rendering.
When the lamp is turned on, the following happens: constantly moving, iodide enters the zone where the temperature is high and decomposes into metal and iodine. The latter, in turn, fall through diffusion into the region of lower temperature, where they are connected again. Such transformations are possible only with high heating of the arc on the axis of the charge and sharp cooling near the walls of the device. Only iodides could not provide all the necessary conditions, so they decided that mercury was needed. And for easier and faster ignition, argon is used.
DRI lamps: characteristics
All devices have a certain power. The minimum value is 250 watts, the maximum is 3500 watts. It is also important to know the voltage (for example, the DRI-400 model has 125 V). The indicator of the current that forms in the lamp can also say a lot. There are a few other special characteristics: color code or temperature, color rendering index, luminous flux and light output. Each type of DRI lamp has its own characteristics indicated on the packaging by the manufacturer.
The advantages of the DRI lamp
Manufacturers guarantee:
- safety and comfort in use throughout the entire service life of the device (on average, domestic models work 10 thousand hours, foreign ones - 5-10 thousand more);
- modest operating costs;
- high luminous flux;
- color rendering coefficient of various sizes.
It should be noted that there are also disadvantages of the DRE type lamp. Some of them cannot be turned on immediately after they have been turned off. Prices for these products are high enough, which sometimes prevents them from being purchased. But such a high cost pays off with economical use and excellent quality characteristics.