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Zirconium getter activation?

Tomps

Member
2015-08-08 8:39 am
How do I use a zirconium getter tube like 6S19P?

The getter is located at the top of the tube and is a thin suspended disk type. There's no flash on the glass.

Picture here. That's a major reseller, that sells them exactly like the ones i have.

Are these tube's plug and play like barium getters?
Is the getter active like this? Or do i need to activate the getter in some way?

An inactive getter can result in a much shortened life, i imagine?
 
The zirconium, like the barium, is heated to orange heat in a thin (almost-but-not-quite evacuated) hydrogen atmosphere. This strips the surface of oxides.

In the case of barium, it also evaporates a bunch of it off, to 'plate' (kind of like sputtering, but different) onto the comparatively cool glass wall.

With zirconium, the oxide tunnels into the underlying metal, leaving a LOT of metal exposed and activated. The pressure tho' of yellow-heated zirconium is so low that it hardly plates onto the glass at all.
Under a sensitive spectroscope, one can see the zirconium plating.

But that's crazy high-physics stuff.
To us ordinary mortals, it just looks like clear glass.
Worry not, the getter is gettering. Zirconium or barium.

⋅-=≡ GoatGuy ✓ ≡=-⋅
 

Tomps

Member
2015-08-08 8:39 am
If a tube dies, do you Barium?

Padumtsssssss :p

@GoatGuy; Thanks a lot!

Found some extra info about these on Jac's website:
This tube features absolutely latest technology. It had gold grids, and a Zirconium top getter. At high temperature, the Zirconium getter gets active, and keeps the tube fresh as on the first day it was made. These getters are better than Barium getters, but can only be used in tubes with a very hot spot inside, to mount it on. This tube is made to run on high power. No need for de-rating. Also the glow picture is amazingly nice, since the cathode can be seen from the sides.
 

Sorento

Member
2008-03-12 9:59 pm
According to "Kohl 1960 Materials and Techniques for Electron Tubes" pp. 592-593:
"Zirconium is an effective getter for O2, N2, CO, CO2 ... these gases are rapidly absorbed at 800 oC, ... H2 at 300 oC ..."

Kohl continues: "The gettering properties of Titanium / Zirconium alloys have been described by Stout and Gibbons. An alloy containing 87% Zr was found most suited for gettering, as it will dissolve its surface oxide film below 200 oC and thus be active in sorbing H2 in addition to O2, N2 and CO2."

The high temperatures reported for pure Zr to be effective explains why it is normally found sputtered on plate electrodes e.g. in hot running transmitting tubes.

The small getter cup visible inside the 6С19П tube may actually contain that Zr/Ta alloy.