Why doesn't a fluorescent lamp implode and shatter ?

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In summary, fluorescent lamps are able to withstand the pressure difference between the outside and inside due to their curved shape, which makes them stronger than flat windows. However, if the lamp shape were rectangular, it would likely shatter unless the glass was very thick. This principle of using curved surfaces for vacuum vessels is seen in various other devices such as CRTs and radio valves.
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Hurricane939
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Accoring to Wikipedia, the pressure inside a fluorescent lamp is 0.3% of the atmospheric pressure, so the pressure difference between the outside and the inside of the lamp is almost equal to the atmospheric pressure which is 1 bar or 14.7 psi.

Now according to this and this, glass shatters at an overpressure of about 1 psi, and sometimes even less than that.

So why doesn't the difference in pressure between the outside and the inside of a fluorescent lamp cause the glass to shatter ?
 
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  • #2
The article is referring to windows, which are flat. Arches (tubes)are much stronger.
 
  • #3
russ_watters said:
The article is referring to windows, which are flat. Arches (tubes)are much stronger.
So if the lamp shape was rectangular for example, would it shatter ?
 
  • #4
Hurricane939 said:
So if the lamp shape was rectangular for example, would it shatter ?
Yes; unless the glass was very thick. The principle of using curved surfaces for vacuum vessels is pretty universal. CRTs, radio valves, dewar flasks . . . . .
 

1. Why doesn't a fluorescent lamp implode and shatter?

A fluorescent lamp contains a gas mixture, typically argon and mercury vapor, that is sealed within the glass tube. When an electric current passes through the gas, it excites the mercury atoms, causing them to emit ultraviolet light. This UV light then strikes the phosphor coating on the inside of the tube, causing it to emit visible light. The gas inside the tube is under low pressure, and the tube is designed to withstand the pressure from the gas. Therefore, it is unlikely for the lamp to implode and shatter.

2. Can a fluorescent lamp implode and shatter if it is damaged or broken?

While it is not common for a fluorescent lamp to implode and shatter, it is possible if the tube is damaged or broken. If the tube is cracked or punctured, the gas inside can escape, causing a rapid decrease in pressure and potentially causing the lamp to implode. It is important to handle fluorescent lamps carefully to avoid any damage that could lead to implosion and shattering.

3. Are there any safety measures in place to prevent fluorescent lamps from imploding and shattering?

Yes, fluorescent lamps are designed with safety measures to prevent implosion and shattering. The glass tube is made of a thick, durable material that can withstand the pressure of the gas inside. Additionally, the ends of the tube are sealed with protective caps that help to contain the gas and prevent any implosion or shattering.

4. Can high temperatures cause a fluorescent lamp to implode and shatter?

High temperatures can increase the pressure inside the lamp and potentially cause implosion and shattering. However, fluorescent lamps are designed to operate within a certain temperature range, typically between 10-50 degrees Celsius. As long as the lamp is not exposed to extreme temperatures outside of this range, it is unlikely for it to implode and shatter.

5. What should I do if I see a fluorescent lamp starting to implode and shatter?

If you notice a fluorescent lamp starting to implode and shatter, it is important to turn it off immediately and handle it with caution. The lamp should be disposed of properly, and any broken pieces should be cleaned up and disposed of in a sealed container. It is also recommended to wear gloves and protective eyewear when handling a damaged fluorescent lamp to avoid any potential injury.

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