Fluorescent lamp is also called fluorescent lamp, its working principle: fluorescent tube is simply a closed gas discharge tube. The main gas in the tube is argon (argon) gas (additionally containing neon neon or krypton krypton) at about 0.3% of atmospheric pressure. Also contains a few drops of mercury - to form trace amounts of mercury vapor. Mercury atoms account for about one thousandth of all gas atoms.
The fluorescent tube is the mercury atom that relies on the lamp tube, releasing the ultraviolet light from the process of gas discharge (the main wavelength is 2537 Å = 2537 x 10-10 m). About 60% of the energy consumed can be converted to ultraviolet light. The other energy is converted to heat.
The fluorescent lamp absorbs ultraviolet light from the fluorescent substance on the inner surface of the lamp to release visible light. Different fluorescent substances will emit different visible light. The efficiency of converting UV light to visible light is about 40%. So the efficiency of the fluorescent lamp is about 60% × 40% = 24% - about twice the same power tungsten wire lamp.