Verschillende vormen van Getters en wat is hun doel? (Techniek Radio/TV)

door 402N , Rotterdam, 03.10.2009, 22:28 (5529 dagen geleden) @ Philip
Bewerkt door 402N, 03.10.2009, 22:45

Niet precies een antwoord op de verschillende vormen, maar toch:

http://en.wikipedia.org/wiki/Getter

Nog even een stukje tekst:

More myths debunked: those Nasty Old Spots (hey, another NOS!) inside the glass. "Burn Spots!" the Holy Grail Seekers scream, "Used Tubes...Junk!!" "NO", my voice of reason, drowned out in the techno-babble melee, implores, "getter spots!" Listen up: these are not burns like a light bulb hooked to high voltage makes. Instead, it is the result of electrically burning a metallic element inside the tube in the factory to remove the last traces of air from the tube and making a hard vacuum. The vaporized metal sputters itself on the glass, kind of like the sputtered aluminum layer inside your compact discs. This silver spot of metal coating acts to trap any residual gas that may leak in over the years. It does this by combining with the gas molecule and oxidizing. Only if the getter spot is white do you have to worry. That indicates the vacuum is lost and all of the getter has oxidized. Some getters don't always stay in one spot, they will sometimes chimney inside the elements if a bottom getter is used, making one or two silver spots on top of the tube. Side getters will sometimes darken a clear top tube, and may show "shadows" of the elements that blocked their path to the glass. Some getters may be black, sometimes with a rainbow iridescence. This just means the getter was deposited at a higher temperature, and the metal oxides are more "mixed up" on the glass. It will work just as well as a silver getter. Folks, listen, I hate to rain on your parade, but the getter spot on the glass has NO EFFECT on the sound the tube will produce. But getter spots are not Nasty Old Stuff!

Jaap