Fluorescent lamp

While larger fluorescent lamps have been mostly used in large commercial or institutional buildings, the compact fluorescent lamp is now being used as an energy-saving alternative to incandescent lamps in homes. Compared withincandescent lamps, fluorescent lamps use less power for the same amount of light, generally last longer, but are bulkier, more complex, and more expensive than a comparable incandescent lamp.

(Typical F71T12 100W bi-pin lamp, used in tanning beds. Note (Hg) symbol indicating it
Contains mercury.)

 flow of power through the lamp. However, a fluorescent lamp converts electrical power into useful light more efficiently than an incandescent lamp; lower energy costs offsets the higher initial cost of the lamp.

Unlike incandescent lamps, fluorescent lamps always require a ballast to regulate the

fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light.

(Assorted types of fluorescent lamps. Top, two Compact fluorescent lamps, bottom, two regular tubes. Matchstick shown for scale.)