2024-04-12
The difference between fluorescent lights and neon lights
The difference between fluorescent lights and neon lights
Rainbow light is a kind of lamp commonly used in advertising signs. These signs are made of long, narrow glass tubes, often bent into various shapes. For example, neon tubes can spell out words. The tubes can also glow in different colors.
A fluorescent lamp, on the other hand, is usually a long, straight tube that emits white light. There are plenty of fluorescent lights in offices, shops and homes.
The concept of neon is simple -- a glass tube containing a low-pressure inert gas, such as neon, argon or krypton, and metal electrodes at either end of the tube. When a high pressure is applied to the electrode, the neon gas ionizes and electrons flow through the gas. These electrons excite the neon atoms, causing them to emit the light we can see. When excited in this way, neon will glow red, while other gases will glow in other colors.
Fluorescent lamps work in a similar way, but with an extra step. Inside the fluorescent lamp, there is a low pressure mercury vapor. When ionized, mercury vapor emits ultraviolet light. The human eye is not sensitive to UV light (although human skin is sensitive to it - see how sunburn and tanning are formed), so fluorescent lamps are coated with fluorescent substances inside. A fluorescent substance is a substance that accepts energy in one form (for example, the energy of a high-speed electron in a picture tube - see how a television works) and emits it in the form of visible light. In fluorescent lamps, the fluorescent material receives the energy of ultraviolet photons and emits visible photons.
Therefore, the light we see from the fluorescent tube is the light emitted by the fluorescent substance coated on the inner surface of the tube (the fluorescent substance fluoresces when excited, hence the name). The light of neon tubes is colored light emitted directly by neon gas.
A fluorescent lamp, on the other hand, is usually a long, straight tube that emits white light. There are plenty of fluorescent lights in offices, shops and homes.
The concept of neon is simple -- a glass tube containing a low-pressure inert gas, such as neon, argon or krypton, and metal electrodes at either end of the tube. When a high pressure is applied to the electrode, the neon gas ionizes and electrons flow through the gas. These electrons excite the neon atoms, causing them to emit the light we can see. When excited in this way, neon will glow red, while other gases will glow in other colors.
Fluorescent lamps work in a similar way, but with an extra step. Inside the fluorescent lamp, there is a low pressure mercury vapor. When ionized, mercury vapor emits ultraviolet light. The human eye is not sensitive to UV light (although human skin is sensitive to it - see how sunburn and tanning are formed), so fluorescent lamps are coated with fluorescent substances inside. A fluorescent substance is a substance that accepts energy in one form (for example, the energy of a high-speed electron in a picture tube - see how a television works) and emits it in the form of visible light. In fluorescent lamps, the fluorescent material receives the energy of ultraviolet photons and emits visible photons.
Therefore, the light we see from the fluorescent tube is the light emitted by the fluorescent substance coated on the inner surface of the tube (the fluorescent substance fluoresces when excited, hence the name). The light of neon tubes is colored light emitted directly by neon gas.
