Type of electric discharge lamp consisting of a glass tube filled with a mixture of argon and mercury vapor. A current of electricity causes the vapor to produce ultraviolet radiation that, in turn, excites a phosphor coating on the inside of the tube, causing it to fluoresce, or reradiate the energy as visible light. Fluorescent lamps are cooler and more efficient than incandescent lamps. They are commonly installed with diffusers as part of a suspended ceiling system. Seealso fluorescence.
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