dont getter what it is

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
Outer Globe arc source metal hallide type lamp, at the top of the lamp there is that little button of stuff in a pan. What it called and what is its purpose? Bonus question, what is this outer globe filled with and what is the AU of it?
 

n1ist

Well-Known Member
Joined
Jun 30, 2005
Location
Malden MA
It's the getter. When building the lamp, they pump it down to remove as much of the air as possible, fill it, and seal it. Then they heat the getter (either by passing a current thru it or inductively) and it chemically combines with any remaining hydrogen. It's the same thing responsible for the shiny coating on the inside of radio tubes.
 

ship

Senior Team Emeritus
Premium Member
Joined
Mar 29, 2003
Location
Illinois
very good. I'll post a photo later. What does it mean if this explodes within the lamp?