Fluorescent Lighting

In fluorescent lighting, electrical energy is converted into radiant energy by a physical process in the fluorescent lamp. The lamp consists of a sealed glass tube containing mercury vapor, an inert gas (such as argon) at low pressure, and a phosphor coating on the inside surface. After ionizing the gas, electrical current flows through the gas between electrodes at the ends of the tube. The current excites the mercury atoms, which then emit ultraviolet light. Ultraviolet (UV) light is not visible to the human eye, but is used to cause fluorescence of the phosphor, which absorbs the UV radiation and produces light in the visible range of the color spectrum. Additional details on fluorescent lamp operation can be found in [3].