Razvan Popescu said:

What wears out in a Rb lamp?

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These are my opinions.  I hate spam.

Hal
I am not sure the bulbs wear out. But on telco Rbs I have seen the Rb
plates out on the glass. Other time-nuts have seen the same.
When that happens the bulb darkens and lowers the transmission. Finally
with enough Rb missing the lamp fails to ignite.
Others and myself have heated the lamp to get the RB back into circulation
and they fire up and run quite well and seem to end up back in the midlife
region. Its really hard to say how good they are but they ignite and lock
and are stable.
Regards
Paul.

On Mon, Aug 28, 2023 at 4:49 PM Hal Murray via time-nuts <
time-nuts@lists.febo.com> wrote:

On 28.08.23 21:59, Hal Murray via time-nuts wrote:

There is a diffusion of the rubidium atoms into the glass envelope of
the lamp. When this is happening and it is visible if you open the case
you will see the dark glass it means the Rb atoms are unavailable to the
discharge. This will make the standard out of calibration.

There was some discussion here on the list that you can use a heat gun
to evaporate that Rb back.

Hi

To some extent, “lamp dies” is a generic excuse for the physics package dying. The issue
may or may not be this or that chunk of it. As noted in other posts, lamps do wear out / go
black from Rb defusing into the glass. There are other things that could happen.

Bob