Incandescence and Fluorescence in Lighting
by Joshua D. Chapman
Two types of lighting are the most popular used today; incandescent and fluorescent. Incandescent light, the most commonly used type, is what people tend to use in their homes because of the softer light it gives. Car lights and flashlights are also incandescent. An incandescent lamp will give off differing amounts of light depending on the amount of electricity being used.
There are three basic components of an incandescent light; the filament, the bulb, and the base. The filament is a thin coiled wire, usually made of tungsten, a strong metal. When electricity flows through the filament the heat produced energizes some of the atoms, which give off their additional energy in the form heat and light. The bulb is usually filled with an inert gas or is under vacuum. This helps prolong the life of the filament and keeps the electricity from jumping inside the bulb. The base holds the bulb in place and provides a connection to the electrical source.
Although still preferred for home use, the incandescent bulb has a much shorter life and consumes roughly three times the electricity of a fluorescent bulb used to light the same area.
Fluorescent lighting is widely used in offices, schools, factories and some homes. A fluorescent lamp is a glass tube that contains mercury vapor and argon gas at a low pressure, A fluorescent lamp needs a starter and a ballast to work. The starter provides the starting voltage through the electrodes at both ends of the lamp. The electrical current heats the electrodes causing electrons to be released. The ballast then sends a surge of current between the electrodes, forming an arc (stream of electrons) in the tube. This causes the vaporized mercury atoms to give off ultraviolet energy. These rays strike the phosphors, which coat the inside walls of the tube and cause the particles to give off visible light.
Very little heat is given off by a fluorescent bulb and the life of a bulb is roughly ten times that of an incandescent bulb. Although most fluorescent lights ore straight tubes, the tube can also be bent in many different shapes or be enclosed in a glass globe.