Thursday, February 23, 2006

Halogen Filament

Sample: A metal filament from a halogen bulb.
Source: My desk lamp.

"Halogen" bulbs operate on the same basic principle as your conventional incandescent bulbs. Electricity flows through a tungsten filament, heating it and causing it to glow. Halogen bulbs, however, run at a much higher temperature (hence all the warnings about touching them, kepping flammables away, etc.) In fact, these bulbs are hot enough to slowly evaporate away their filaments. The halogen moniker comes from the presence of a tiny amount of iodine vapor present in the otherwise near-vaccuum of the bulb. Tungsten evaporated from the filament reacts with the iodine, which assists in redepositing back on the filament, extending the life of the bulb.

The 200x image here is another one of my personal favorites. Science as art.

Filament, 10x.

Filament, 60x.

Filament, 200x.


Post a Comment

Links to this post:

Create a Link

<< Home