A fluorescent light consists of long tubular globes and a light fixture. Fluorescent tubes have capped ends with two external pins. They are coated inside with phosphorus and filled with argon gas and a small amount of mercury. They are more energy efficient that normal incandescent globes and are often used in places where bright light is required. Office buildings and schools often use fluorescent lighting for these reasons and many people install fluorescent lighting on their porch, in their garages or in their kitchens to provide strong lighting for those areas. Fluorescent lights work in a different way to the standard incandescent bulb. Read this article to learn more about how they work.
How Do Fluorescent Lights Work?
Each type of light producing object such as normal incandescent globes and fluorescent light bulbs use a form if energy to excite the atoms contained in the globe. Put simply, fluorescent tubes use electricity to excite the mercury vapor inside the lamp. Inside each fluorescent tube is an inert gas such as argon, a tiny bit of mercury and phosphorus coated glass. When the tube is connected to a power supply (such as a light fixture) via its contact pins a current begins to flow through the electrodes inside the glass tube. This voltage causes the electrons in the gas to move from one end of the tube to the other. The movement of the electrons changes some of the liquid mercury into gas form. As the electrons move through the tube some of them will collide with the mercury gas atoms. The collision excites the atoms and makes the electrons jump into higher orbits. When they return to their normal state they release energy in the form of light photons and this is how the light is produced.
Mercury atoms release ultraviolet (UV) light which cannot be seen by the naked human eye, so the light has to be filtered in some way to allow visible light to be produced. This is why fluorescent tubes are coated with phosphorus. Phosphorus is a substance that gives off light when it absorbs UV light. When the phosphorus atoms hit one of the light photons given off by the mercury atoms the phosphorus atoms are excited in the same way. When they return to their original orbit they release energy in the form of light photons and the fluorescent tube produces light that we can see.
Did you know?
Mercury is hazardous to human health, which means that fluorescent bulbs should be disposed of safely.
The conversion of UV rays to visible light with phosphorus is known as fluorescence and this is where this type of light bulb gets its name.