[time-nuts] Helium and MEMS oscillators don;t mix well

Poul-Henning Kamp phk at phk.freebsd.dk
Thu Nov 1 18:27:21 EDT 2018

In message <04055a33-5f2b-8aff-f9b0-526c9478d3b8 at earthlink.net>, jimlux writes:

>> 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.

We're talking across each other here, I was referring to the PRS
anecdote from Karl.

I'll absolutely belive that you can screw up certain kinds of MEMS
devices when you dump 90 kg of Helium into a building.

>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.

That's not my experience, most ${GAS}-level detectors are based on
some kind of chemical reactivty (or spectroscopy if they are _really_
expensive) and they tend to just ignore helium and other noble gasses.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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Never attribute to malice what can adequately be explained by incompetence.

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