Wikijunior:How Things Work/Fluorescent Lamp

Fluorescent lamps make light from hydrogen and phosphor.

Who invented it?
Many people did, including Thomas Edison, Georges Claude and Heinrich Geissler.

How does it get power?
When you plug the cord into a wall, it uses electrical current. When the current gets faster, it heats up, giving it a glow.

How does it work?
A fluorescent lamp consists of a tube containing a gas, Mercury, and special coating on the inside surface, Phosphor. A coil inside the tube is heated and emits electrons which collide with the atoms of Mercury inside the tube. The gas produces invisible ultraviolet rays which, when they meet the phosphor, which coats the tube, turns into visible light, which we see.

How dangerous is it?
Mercury is very poisonous and can kill. The lamp should not be used if damaged as it may leak mercury fumes. Instead if should be carefully disposed of. Often local authorities have special instructions for the disposal of fluorescent lamps to make sure the mercury does not spread into the environment or nearby water sourses.

What does it do?
They are a type of light and are used to make it easier to see in dark places. Light is produced when the phosphor lights up.

How has it changed the world?
Fluorescent Lamps use less electricity than traditional light bulbs, because they produce less heat. Incandescent light bulbs use a significant proportion of the energy producing heat, which is not very useful. Therefore, more energy is needed to make the same amount of light, because much is wasted.