When evening comes and the ultimate source of light during the day, the sun, brightens the other half of the globe, with just one switch another light comes – a lighting device. Artificial illumination or lighting has been seen as the best way to shelter humans from the dangers of the night. Its main use is illustrated in campfires, candles, oil-burning lamps, kerosene lamps, the incandescent lamp, and the most widely used fluorescent light bulbs.
Fluorescent light bulbs belong to the lighting device group of discharge tubes. The fluorescent light is an efficient light source which uses a mercury arc and a phosphor coating inside its tubes. These glass tubes are filled with the metal vapor which glows when it is ionized by the electrodes that passes at both ends of the tubes. Much of its energy is emitted in the ultraviolet range which is converted to visible light by the phosphor lining of the tubes. Depending on the phosphors used, a range of colors can be given off.
Production of fluorescent bulbs is more costly than its predecessor, the incandescent bulb because of its ballast requirement for stabilizing its flow of current. But this cost is paid off by its efficiency in reducing electric cost which is highly advantageous to most industrialized cities. Most countries in Southeast and East Asia the use of incandescent bulbs are a rare phenomenon especially for lighting its buildings. The use of the fluorescent lamp has dramatically increased with the advent of the compact fluorescent light bulbs or CFL. They come in many different shapes and sizes depending on the lighting fixture installed in the home or office.
Aside from its luminous efficacy, which is its ability to convert more visible light from a given power input, fluorescent lamps also reduce the energy consumption, size and cost of an air-conditioning equipment because it gives off less heat than incandescent lamps. Its longer lamp life also reduces the labor cost of frequently replacing old bulbs.
There are different subsets of fluorescent lamps, some of which are used for cosmetics and therapy. Black light lamps are used to generate near ultraviolet light which is then used to provoke fluorescence in materials that would otherwise be invisible to the naked eye. Tanning lamps which typically has 3-5 more phosphors discharges both UVA and UVB light which is responsible for the tanning response of the skin. Grow lamps, infrared lamps, Bilirubin lamps, germicidal lamps, electrodeless lamps, and Cold-cathode fluorescent lamps are among the other variants of fluorescent lamps.
