[time-nuts] Re: hydrogen rich environment and oscillators

[Alex Pummer]

Look for Knutdsen effect:
Knudsen diffusion, or Knudsen flux, *occurs when the mean pore diameter 
of the porous medium is smaller than the mean free path of the gas 
particles*. This type of diffusion occurs in low permeability porous 
media, which have small pore radii, and at low gas pressures, when the 
mean free path becomes large.
73
KJ6UHN

On 12/12/2022 2:09 PM, Lux, Jim via time-nuts wrote:
> On 12/12/22 11:21 AM, Zen via time-nuts wrote:
>> This is true and was proven by experimentation. But I believe it was a
>> Helium atmosphere not Hydrogen. The He poisoned the MEMS oscillator 
>> in both
>> phones and watches. Fault time was about 30 minutes recovery time was 
>> about
>> 3 days. Concentrations were small enough that and employee filling party
>> balloons at a store had a dead I phone for a while.
>
> Yes, but H2, while a bit bigger than He, is still pretty diffusable 
> (if that's the right word).
>
> And, I believe the iPhone event was a very tiny MEMS resonator in a 
> vacuum.
>
> I've been poking through the literature and reports, but it does not 
> appear to be a "well studied problem".
>
>
> The challenge is that with Cubesats and the like making more use of 
> COTS components and techniques, there's not a lot of history to go 
> back to.  Space qualified parts get leak tested with He, etc. so their 
> hermeticity is generally good.  The same is not necessarily true of 
> other devices.
>
>
>
>
>
>>
>> Eric
>>
>> -----Original Message-----
>> From: Poul-Henning Kamp via time-nuts <time-nuts at lists.febo.com>
>> Sent: Monday, December 12, 2022 10:10 AM
>> To: Discussion of precise time and frequency measurement
>> <time-nuts at lists.febo.com>
>> Cc: Poul-Henning Kamp <phk at phk.freebsd.dk>
>> Subject: [time-nuts] Re: hydrogen rich environment and oscillators
>>
>> --------
>> Lux, Jim via time-nuts writes:
>>
>>> Does anyone have any information on what happens to hermetic TCXOs
>>> when they're in a hydrogen rich atmosphere?
>> What kind of hydrogen concentration are we talking about ?
>>
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