[time-nuts] Helium and MEMS oscillators don;t mix well
jimlux
jimlux at earthlink.net
Thu Nov 1 16:22:54 UTC 2018
On 11/1/18 8:52 AM, Poul-Henning Kamp wrote:
> --------
> In message <B084B24B-DD81-48A2-87AE-D43D74133C59 at n1k.org>, Bob kb8tq writes:
>
>> A lot of Radon and *really* poor ventilation….
>
> Yup.
>
> But a LOT of Radon is not without interesting "side-effects", such as
> much easier ionization due to the alpha radiation.
>
> To get to relevant He levels via the Radon route, we are talking
> deep unventilated mineshaft kind of concentrations...
>
> Hydrogen is a lot more plausible in my view.
>
>
Yeah, but in concentrations typical in the "room", I doubt you'd see the
effect. The experimenters put the phone in a bag full of helium and it
took hours. I would expect the same in hydrogen.
That's a lot different than a <1% concentration. I assure you, that if
there was a helium leak/vent/boil off that made the room concentration
1%, the room oxygen sensor would be alarming (having dropped to 20%) and
people would be running for the doors.
I'd be betting more on some RFI/EMI issue from the RF fields or the
magnetic fields, both of which are quite strong in an MRI facility.
However, in true time-nuts fashion, I'm going to rummage around for some
older SiTime oscillators on an eval board at work, and we can do a
*real* test.
I got some samples from them a few years ago, so all I have to do is
find that tiny plastic bag with the tiny 2x2mm parts in it.
Then I have to find some spare hydrogen and helium..
After all, we really need to evaluate it in an atmosphere of Argon and
CO2, (Mars gas) - I'll see if we've got some around - we were doing RF
breakdown tests in simulated Martian atmosphere <grin> (BTW, the
Martian atmosphere is unique in that it probably has the lowest "minimum
sparking voltage" in the universe)
More information about the Time-nuts_lists.febo.com
mailing list