BC
Bob Camp
Tue, Dec 13, 2022 1:57 PM
Hi
If you have a welded package TCXO, it’s a reasonable guess that it may have gone
through the normal “mil spec” leak test. Mil STD-202 method 112 test condition C
gives you all sorts of fun information. It also heads off in many directions.
As normally done on a crystal oscillator, you put the parts in a pressure vessel for
about an hour. It’s pressurized at around 50 PSI with 10% helium. Yes both the time
and pressure are past what method 112 calls out as the minimums.
After being soaked like this, they go into a mass spectrometer to look for helium
coming back out of the parts.
Pretty much any mil spec or space spec welded part would go through that test or
something very much like it. That’s true regardless of who made the part.
The only relevant point here is that if this sort of exposure killed the parts, it would
show up and folks would very much know about it.
Welded crystals going into precision oscillators get the same sort of leak check or
possibly something more in depth. There’s no guarantee on this so it’s not quite as
much a sure thing as the space or mil oscillators. Still, if this killed crystals you would
know about it.
Before anybody asks, yes, some parts do leak. I don’t remember any of them being
non-functional. However, you don’t test those parts much. They are headed to the
recycle bin.
Bob
On Dec 12, 2022, at 5:09 PM, Lux, Jim via time-nuts time-nuts@lists.febo.com 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@lists.febo.com
Sent: Monday, December 12, 2022 10:10 AM
To: Discussion of precise time and frequency measurement
time-nuts@lists.febo.com
Cc: Poul-Henning Kamp phk@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 ?
Hi
If you have a welded package TCXO, it’s a reasonable guess that it may have gone
through the normal “mil spec” leak test. Mil STD-202 method 112 test condition C
gives you all sorts of fun information. It also heads off in many directions.
As normally done on a crystal oscillator, you put the parts in a pressure vessel for
about an hour. It’s pressurized at around 50 PSI with 10% helium. Yes both the time
and pressure are past what method 112 calls out as the minimums.
After being soaked like this, they go into a mass spectrometer to look for helium
coming back out of the parts.
Pretty much any mil spec or space spec welded part would go through that test or
something very much like it. That’s true regardless of who made the part.
The only relevant point here is that if this sort of exposure killed the parts, it would
show up and folks would very much know about it.
Welded crystals going into precision oscillators get the same sort of leak check or
possibly something more in depth. There’s no guarantee on this so it’s not quite as
much a sure thing as the space or mil oscillators. Still, if this killed crystals you would
know about it.
Before anybody asks, yes, some parts do leak. I don’t remember any of them being
non-functional. However, you don’t test those parts much. They are headed to the
recycle bin.
Bob
> On Dec 12, 2022, at 5:09 PM, Lux, Jim via time-nuts <time-nuts@lists.febo.com> 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@lists.febo.com>
>> Sent: Monday, December 12, 2022 10:10 AM
>> To: Discussion of precise time and frequency measurement
>> <time-nuts@lists.febo.com>
>> Cc: Poul-Henning Kamp <phk@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 ?
>>
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe send an email to time-nuts-leave@lists.febo.com
LJ
Lux, Jim
Tue, Dec 13, 2022 3:01 PM
On 12/13/22 5:57 AM, Bob Camp wrote:
Hi
If you have a welded package TCXO, it’s a reasonable guess that it may have gone
through the normal “mil spec” leak test. Mil STD-202 method 112 test condition C
gives you all sorts of fun information. It also heads off in many directions.
As normally done on a crystal oscillator, you put the parts in a pressure vessel for
about an hour. It’s pressurized at around 50 PSI with 10% helium. Yes both the time
and pressure are past what method 112 calls out as the minimums.
After being soaked like this, they go into a mass spectrometer to look for helium
coming back out of the parts.
Pretty much any mil spec or space spec welded part would go through that test or
something very much like it. That’s true regardless of who made the part.
The only relevant point here is that if this sort of exposure killed the parts, it would
show up and folks would very much know about it.
Welded crystals going into precision oscillators get the same sort of leak check or
possibly something more in depth. There’s no guarantee on this so it’s not quite as
much a sure thing as the space or mil oscillators. Still, if this killed crystals you would
know about it.
Before anybody asks, yes, some parts do leak. I don’t remember any of them being
non-functional. However, you don’t test those parts much. They are headed to the
recycle bin.
Bob
OK. so welded packages (particularly those that are procured for space)
aren't likely to leak, they tested, etc. I'm sort of interested, though
in COTS cheap oscillators like these tiny $1 Abracon units. (I don't
know what they use on Arduinos and RPi, but it's something like this).
https://www.mouser.com/datasheet/2/3/ASEseries-38758.pdf
They're sort of silent on the datasheet about sealing, etc. And at
$1.38 each, do they actually leak test them?
On 12/13/22 5:57 AM, Bob Camp wrote:
> Hi
>
> If you have a welded package TCXO, it’s a reasonable guess that it may have gone
> through the normal “mil spec” leak test. Mil STD-202 method 112 test condition C
> gives you all sorts of fun information. It also heads off in many directions.
>
> As normally done on a crystal oscillator, you put the parts in a pressure vessel for
> about an hour. It’s pressurized at around 50 PSI with 10% helium. Yes both the time
> and pressure are past what method 112 calls out as the minimums.
>
> After being soaked like this, they go into a mass spectrometer to look for helium
> coming back out of the parts.
>
> Pretty much any mil spec or space spec welded part would go through that test or
> something very much like it. That’s true regardless of who made the part.
>
> The only relevant point here is that if this sort of exposure killed the parts, it would
> show up and folks would very much know about it.
>
> Welded crystals going into precision oscillators get the same sort of leak check or
> possibly something more in depth. There’s no guarantee on this so it’s not quite as
> much a sure thing as the space or mil oscillators. Still, if this killed crystals you would
> know about it.
>
> Before anybody asks, yes, some parts do leak. I don’t remember any of them being
> non-functional. However, you don’t test those parts much. They are headed to the
> recycle bin.
>
> Bob
OK. so welded packages (particularly those that are procured for space)
aren't likely to leak, they tested, etc. I'm sort of interested, though
in COTS cheap oscillators like these tiny $1 Abracon units. (I don't
know what they use on Arduinos and RPi, but it's something like this).
https://www.mouser.com/datasheet/2/3/ASEseries-38758.pdf
They're sort of silent on the datasheet about sealing, etc. And at
$1.38 each, do they actually leak test them?
BC
Bob Camp
Tue, Dec 13, 2022 5:09 PM
Hi
As price goes down, so must cost. If not, the outfit goes broke. Working
out just what gets “left out” on a $1 TCXO is almost impossible unless
you can go do an audit of the production line at the time the parts are
being made.
Next question would be: Are the parts evacuated before seal? I’d bet not.
They likely get some sort of inert gas fill and that’s about it. If so, you
already have gas in the package. There’s not a lot that a one gas
will do vs another as far as damping the crystal. Also, with a more or less
zero pressure differential, not much He or H is going to work it’s way into
the package. Yes, this assumes the parts are crystal based ….
It’s not all that hard to test this out. Get or rig a pressure container that
will take 50 to 100 PSI. Go over to the local gas store and get a small
bottle of He or H. Bomb the parts overnight at 50 to 100 PSI. Pull them
out and see if they still work …… If so, you have just done what is likely
the “100 year test” on the parts. If they don’t work, see if you have crushed
the parts ( = smashed the package flat …) and try again at a lower
pressure … :)
Bob
On Dec 13, 2022, at 10:01 AM, Lux, Jim jim@luxfamily.com wrote:
On 12/13/22 5:57 AM, Bob Camp wrote:
Hi
If you have a welded package TCXO, it’s a reasonable guess that it may have gone
through the normal “mil spec” leak test. Mil STD-202 method 112 test condition C
gives you all sorts of fun information. It also heads off in many directions.
As normally done on a crystal oscillator, you put the parts in a pressure vessel for
about an hour. It’s pressurized at around 50 PSI with 10% helium. Yes both the time
and pressure are past what method 112 calls out as the minimums.
After being soaked like this, they go into a mass spectrometer to look for helium
coming back out of the parts.
Pretty much any mil spec or space spec welded part would go through that test or
something very much like it. That’s true regardless of who made the part.
The only relevant point here is that if this sort of exposure killed the parts, it would
show up and folks would very much know about it.
Welded crystals going into precision oscillators get the same sort of leak check or
possibly something more in depth. There’s no guarantee on this so it’s not quite as
much a sure thing as the space or mil oscillators. Still, if this killed crystals you would
know about it.
Before anybody asks, yes, some parts do leak. I don’t remember any of them being
non-functional. However, you don’t test those parts much. They are headed to the
recycle bin.
Bob
OK. so welded packages (particularly those that are procured for space) aren't likely to leak, they tested, etc. I'm sort of interested, though in COTS cheap oscillators like these tiny $1 Abracon units. (I don't know what they use on Arduinos and RPi, but it's something like this).
https://www.mouser.com/datasheet/2/3/ASEseries-38758.pdf
They're sort of silent on the datasheet about sealing, etc. And at $1.38 each, do they actually leak test them?
Hi
As price goes down, so must cost. If not, the outfit goes broke. Working
out just what gets “left out” on a $1 TCXO is almost impossible unless
you can go do an audit of the production line at the time the parts are
being made.
Next question would be: Are the parts evacuated before seal? I’d bet not.
They likely get some sort of inert gas fill and that’s about it. If so, you
already *have* gas in the package. There’s not a lot that a one gas
will do vs another as far as damping the crystal. Also, with a more or less
zero pressure differential, not much He or H is going to work it’s way into
the package. Yes, this *assumes* the parts are crystal based ….
It’s not all that hard to test this out. Get or rig a pressure container that
will take 50 to 100 PSI. Go over to the local gas store and get a small
bottle of He or H. Bomb the parts overnight at 50 to 100 PSI. Pull them
out and see if they still work …… If so, you have just done what is likely
the “100 year test” on the parts. If they don’t work, see if you have crushed
the parts ( = smashed the package flat …) and try again at a lower
pressure … :)
Bob
> On Dec 13, 2022, at 10:01 AM, Lux, Jim <jim@luxfamily.com> wrote:
>
> On 12/13/22 5:57 AM, Bob Camp wrote:
>> Hi
>>
>> If you have a welded package TCXO, it’s a reasonable guess that it may have gone
>> through the normal “mil spec” leak test. Mil STD-202 method 112 test condition C
>> gives you all sorts of fun information. It also heads off in many directions.
>>
>> As normally done on a crystal oscillator, you put the parts in a pressure vessel for
>> about an hour. It’s pressurized at around 50 PSI with 10% helium. Yes both the time
>> and pressure are past what method 112 calls out as the minimums.
>>
>> After being soaked like this, they go into a mass spectrometer to look for helium
>> coming back out of the parts.
>>
>> Pretty much any mil spec or space spec welded part would go through that test or
>> something very much like it. That’s true regardless of who made the part.
>>
>> The only relevant point here is that if this sort of exposure killed the parts, it would
>> show up and folks would very much know about it.
>>
>> Welded crystals going into precision oscillators get the same sort of leak check or
>> possibly something more in depth. There’s no guarantee on this so it’s not quite as
>> much a sure thing as the space or mil oscillators. Still, if this killed crystals you would
>> know about it.
>>
>> Before anybody asks, yes, some parts do leak. I don’t remember any of them being
>> non-functional. However, you don’t test those parts much. They are headed to the
>> recycle bin.
>>
>> Bob
>
>
> OK. so welded packages (particularly those that are procured for space) aren't likely to leak, they tested, etc. I'm sort of interested, though in COTS cheap oscillators like these tiny $1 Abracon units. (I don't know what they use on Arduinos and RPi, but it's something like this).
>
> https://www.mouser.com/datasheet/2/3/ASEseries-38758.pdf
>
> They're sort of silent on the datasheet about sealing, etc. And at $1.38 each, do they actually leak test them?
>
>
>
>
>
LJ
Lux, Jim
Tue, Dec 13, 2022 5:56 PM
On 12/13/22 9:09 AM, Bob Camp wrote:
Hi
As price goes down, so must cost. If not, the outfit goes broke. Working
out just what gets “left out” on a $1 TCXO is almost impossible unless
you can go do an audit of the production line at the time the parts are
being made.
Next question would be: Are the parts evacuated before seal? I’d bet not.
They likely get some sort of inert gas fill and that’s about it. If so, you
already have gas in the package. There’s not a lot that a one gas
will do vs another as far as damping the crystal. Also, with a more or less
zero pressure differential, not much He or H is going to work it’s way into
the package. Yes, this assumes the parts are crystal based ….
That's kind of what I thought. I would think that if it's a MEMS
device, that the mfr would identify it as such. The Abracon part does
say "Crystal Oscillator" at the top of the data sheet.
It’s not all that hard to test this out. Get or rig a pressure container that
will take 50 to 100 PSI. Go over to the local gas store and get a small
bottle of He or H. Bomb the parts overnight at 50 to 100 PSI. Pull them
out and see if they still work …… If so, you have just done what is likely
the “100 year test” on the parts. If they don’t work, see if you have crushed
the parts ( = smashed the package flat …) and try again at a lower
pressure … :)
Good idea.
An excellent project for a summer intern.
Of course, at JPL, we'd be much more elaborate, budget permitting - CAT
scan the package before and after, set up a RGA or Mass Spec, Bring in
an optical fiber(s)) from the maser to compare the frequency of the
oscillator. Certify all the high pressure gas handling equipment. The
test process alone could cost more than buying 100,000 oscillators.
In my garage - the work of a weekend.
On Dec 13, 2022, at 10:01 AM, Lux, Jim jim@luxfamily.com wrote:
On 12/13/22 5:57 AM, Bob Camp wrote:
Hi
If you have a welded package TCXO, it’s a reasonable guess that it may have gone
through the normal “mil spec” leak test. Mil STD-202 method 112 test condition C
gives you all sorts of fun information. It also heads off in many directions.
As normally done on a crystal oscillator, you put the parts in a pressure vessel for
about an hour. It’s pressurized at around 50 PSI with 10% helium. Yes both the time
and pressure are past what method 112 calls out as the minimums.
After being soaked like this, they go into a mass spectrometer to look for helium
coming back out of the parts.
Pretty much any mil spec or space spec welded part would go through that test or
something very much like it. That’s true regardless of who made the part.
The only relevant point here is that if this sort of exposure killed the parts, it would
show up and folks would very much know about it.
Welded crystals going into precision oscillators get the same sort of leak check or
possibly something more in depth. There’s no guarantee on this so it’s not quite as
much a sure thing as the space or mil oscillators. Still, if this killed crystals you would
know about it.
Before anybody asks, yes, some parts do leak. I don’t remember any of them being
non-functional. However, you don’t test those parts much. They are headed to the
recycle bin.
Bob
OK. so welded packages (particularly those that are procured for space) aren't likely to leak, they tested, etc. I'm sort of interested, though in COTS cheap oscillators like these tiny $1 Abracon units. (I don't know what they use on Arduinos and RPi, but it's something like this).
https://www.mouser.com/datasheet/2/3/ASEseries-38758.pdf
They're sort of silent on the datasheet about sealing, etc. And at $1.38 each, do they actually leak test them?
On 12/13/22 9:09 AM, Bob Camp wrote:
> Hi
>
> As price goes down, so must cost. If not, the outfit goes broke. Working
> out just what gets “left out” on a $1 TCXO is almost impossible unless
> you can go do an audit of the production line at the time the parts are
> being made.
>
> Next question would be: Are the parts evacuated before seal? I’d bet not.
> They likely get some sort of inert gas fill and that’s about it. If so, you
> already *have* gas in the package. There’s not a lot that a one gas
> will do vs another as far as damping the crystal. Also, with a more or less
> zero pressure differential, not much He or H is going to work it’s way into
> the package. Yes, this *assumes* the parts are crystal based ….
That's kind of what I thought. I would think that if it's a MEMS
device, that the mfr would identify it as such. The Abracon part does
say "Crystal Oscillator" at the top of the data sheet.
>
> It’s not all that hard to test this out. Get or rig a pressure container that
> will take 50 to 100 PSI. Go over to the local gas store and get a small
> bottle of He or H. Bomb the parts overnight at 50 to 100 PSI. Pull them
> out and see if they still work …… If so, you have just done what is likely
> the “100 year test” on the parts. If they don’t work, see if you have crushed
> the parts ( = smashed the package flat …) and try again at a lower
> pressure … :)
Good idea.
An excellent project for a summer intern.
Of course, at JPL, we'd be much more elaborate, budget permitting - CAT
scan the package before and after, set up a RGA or Mass Spec, Bring in
an optical fiber(s)) from the maser to compare the frequency of the
oscillator. Certify all the high pressure gas handling equipment. The
test process alone could cost more than buying 100,000 oscillators.
In my garage - the work of a weekend.
>
> Bob
>
>> On Dec 13, 2022, at 10:01 AM, Lux, Jim <jim@luxfamily.com> wrote:
>>
>> On 12/13/22 5:57 AM, Bob Camp wrote:
>>> Hi
>>>
>>> If you have a welded package TCXO, it’s a reasonable guess that it may have gone
>>> through the normal “mil spec” leak test. Mil STD-202 method 112 test condition C
>>> gives you all sorts of fun information. It also heads off in many directions.
>>>
>>> As normally done on a crystal oscillator, you put the parts in a pressure vessel for
>>> about an hour. It’s pressurized at around 50 PSI with 10% helium. Yes both the time
>>> and pressure are past what method 112 calls out as the minimums.
>>>
>>> After being soaked like this, they go into a mass spectrometer to look for helium
>>> coming back out of the parts.
>>>
>>> Pretty much any mil spec or space spec welded part would go through that test or
>>> something very much like it. That’s true regardless of who made the part.
>>>
>>> The only relevant point here is that if this sort of exposure killed the parts, it would
>>> show up and folks would very much know about it.
>>>
>>> Welded crystals going into precision oscillators get the same sort of leak check or
>>> possibly something more in depth. There’s no guarantee on this so it’s not quite as
>>> much a sure thing as the space or mil oscillators. Still, if this killed crystals you would
>>> know about it.
>>>
>>> Before anybody asks, yes, some parts do leak. I don’t remember any of them being
>>> non-functional. However, you don’t test those parts much. They are headed to the
>>> recycle bin.
>>>
>>> Bob
>>
>> OK. so welded packages (particularly those that are procured for space) aren't likely to leak, they tested, etc. I'm sort of interested, though in COTS cheap oscillators like these tiny $1 Abracon units. (I don't know what they use on Arduinos and RPi, but it's something like this).
>>
>> https://www.mouser.com/datasheet/2/3/ASEseries-38758.pdf
>>
>> They're sort of silent on the datasheet about sealing, etc. And at $1.38 each, do they actually leak test them?
>>
>>
>>
>>
>>
>
EG
Eric Garner
Tue, Dec 13, 2022 6:17 PM
Of course, at JPL, we'd be much more elaborate, budget permitting - CAT
scan the package before and after, set up a RGA or Mass Spec, Bring in
an optical fiber(s)) from the maser to compare the frequency of the
oscillator. Certify all the high pressure gas handling equipment. The
test process alone could cost more than buying 100,000 oscillators.
if it's anything like where I work, If you don't test it that way, and
something happens you'll get yelled at for not doing due diligence. If you
do, and nothing happens you'll get yelled at for wasting money
eric
On Tue, Dec 13, 2022 at 10:04 AM Lux, Jim via time-nuts <
time-nuts@lists.febo.com> wrote:
On 12/13/22 9:09 AM, Bob Camp wrote:
Hi
As price goes down, so must cost. If not, the outfit goes broke. Working
out just what gets “left out” on a $1 TCXO is almost impossible unless
you can go do an audit of the production line at the time the parts are
being made.
Next question would be: Are the parts evacuated before seal? I’d bet not.
They likely get some sort of inert gas fill and that’s about it. If so,
already have gas in the package. There’s not a lot that a one gas
will do vs another as far as damping the crystal. Also, with a more or
zero pressure differential, not much He or H is going to work it’s way
the package. Yes, this assumes the parts are crystal based ….
That's kind of what I thought. I would think that if it's a MEMS
device, that the mfr would identify it as such. The Abracon part does
say "Crystal Oscillator" at the top of the data sheet.
It’s not all that hard to test this out. Get or rig a pressure container
will take 50 to 100 PSI. Go over to the local gas store and get a small
bottle of He or H. Bomb the parts overnight at 50 to 100 PSI. Pull them
out and see if they still work …… If so, you have just done what is
the “100 year test” on the parts. If they don’t work, see if you have
the parts ( = smashed the package flat …) and try again at a lower
pressure … :)
Good idea.
An excellent project for a summer intern.
Of course, at JPL, we'd be much more elaborate, budget permitting - CAT
scan the package before and after, set up a RGA or Mass Spec, Bring in
an optical fiber(s)) from the maser to compare the frequency of the
oscillator. Certify all the high pressure gas handling equipment. The
test process alone could cost more than buying 100,000 oscillators.
In my garage - the work of a weekend.
On Dec 13, 2022, at 10:01 AM, Lux, Jim jim@luxfamily.com wrote:
On 12/13/22 5:57 AM, Bob Camp wrote:
Hi
If you have a welded package TCXO, it’s a reasonable guess that it may
through the normal “mil spec” leak test. Mil STD-202 method 112 test
gives you all sorts of fun information. It also heads off in many
As normally done on a crystal oscillator, you put the parts in a
about an hour. It’s pressurized at around 50 PSI with 10% helium. Yes
and pressure are past what method 112 calls out as the minimums.
After being soaked like this, they go into a mass spectrometer to look
coming back out of the parts.
Pretty much any mil spec or space spec welded part would go through
something very much like it. That’s true regardless of who made the
The only relevant point here is that if this sort of exposure killed
show up and folks would very much know about it.
Welded crystals going into precision oscillators get the same sort of
possibly something more in depth. There’s no guarantee on this so it’s
much a sure thing as the space or mil oscillators. Still, if this
killed crystals you would
know about it.
Before anybody asks, yes, some parts do leak. I don’t remember any of
non-functional. However, you don’t test those parts much. They are
OK. so welded packages (particularly those that are procured for space)
aren't likely to leak, they tested, etc. I'm sort of interested, though in
COTS cheap oscillators like these tiny $1 Abracon units. (I don't know
what they use on Arduinos and RPi, but it's something like this).
$1.38 each, do they actually leak test them?
>
> Of course, at JPL, we'd be much more elaborate, budget permitting - CAT
> scan the package before and after, set up a RGA or Mass Spec, Bring in
> an optical fiber(s)) from the maser to compare the frequency of the
> oscillator. Certify all the high pressure gas handling equipment. The
> test process alone could cost more than buying 100,000 oscillators.
if it's anything like where I work, If you don't test it that way, and
something happens you'll get yelled at for not doing due diligence. If you
do, and nothing happens you'll get yelled at for wasting money
eric
On Tue, Dec 13, 2022 at 10:04 AM Lux, Jim via time-nuts <
time-nuts@lists.febo.com> wrote:
> On 12/13/22 9:09 AM, Bob Camp wrote:
> > Hi
> >
> > As price goes down, so must cost. If not, the outfit goes broke. Working
> > out just what gets “left out” on a $1 TCXO is almost impossible unless
> > you can go do an audit of the production line at the time the parts are
> > being made.
> >
> > Next question would be: Are the parts evacuated before seal? I’d bet not.
> > They likely get some sort of inert gas fill and that’s about it. If so,
> you
> > already *have* gas in the package. There’s not a lot that a one gas
> > will do vs another as far as damping the crystal. Also, with a more or
> less
> > zero pressure differential, not much He or H is going to work it’s way
> into
> > the package. Yes, this *assumes* the parts are crystal based ….
>
>
>
> That's kind of what I thought. I would think that if it's a MEMS
> device, that the mfr would identify it as such. The Abracon part does
> say "Crystal Oscillator" at the top of the data sheet.
>
>
> >
> > It’s not all that hard to test this out. Get or rig a pressure container
> that
> > will take 50 to 100 PSI. Go over to the local gas store and get a small
> > bottle of He or H. Bomb the parts overnight at 50 to 100 PSI. Pull them
> > out and see if they still work …… If so, you have just done what is
> likely
> > the “100 year test” on the parts. If they don’t work, see if you have
> crushed
> > the parts ( = smashed the package flat …) and try again at a lower
> > pressure … :)
>
> Good idea.
>
> An excellent project for a summer intern.
>
> Of course, at JPL, we'd be much more elaborate, budget permitting - CAT
> scan the package before and after, set up a RGA or Mass Spec, Bring in
> an optical fiber(s)) from the maser to compare the frequency of the
> oscillator. Certify all the high pressure gas handling equipment. The
> test process alone could cost more than buying 100,000 oscillators.
>
> In my garage - the work of a weekend.
>
>
>
>
> >
> > Bob
> >
> >> On Dec 13, 2022, at 10:01 AM, Lux, Jim <jim@luxfamily.com> wrote:
> >>
> >> On 12/13/22 5:57 AM, Bob Camp wrote:
> >>> Hi
> >>>
> >>> If you have a welded package TCXO, it’s a reasonable guess that it may
> have gone
> >>> through the normal “mil spec” leak test. Mil STD-202 method 112 test
> condition C
> >>> gives you all sorts of fun information. It also heads off in many
> directions.
> >>>
> >>> As normally done on a crystal oscillator, you put the parts in a
> pressure vessel for
> >>> about an hour. It’s pressurized at around 50 PSI with 10% helium. Yes
> both the time
> >>> and pressure are past what method 112 calls out as the minimums.
> >>>
> >>> After being soaked like this, they go into a mass spectrometer to look
> for helium
> >>> coming back out of the parts.
> >>>
> >>> Pretty much any mil spec or space spec welded part would go through
> that test or
> >>> something very much like it. That’s true regardless of who made the
> part.
> >>>
> >>> The only relevant point here is that if this sort of exposure killed
> the parts, it would
> >>> show up and folks would very much know about it.
> >>>
> >>> Welded crystals going into precision oscillators get the same sort of
> leak check or
> >>> possibly something more in depth. There’s no guarantee on this so it’s
> not quite as
> >>> much a sure thing as the space or mil oscillators. Still, if this
> killed crystals you would
> >>> know about it.
> >>>
> >>> Before anybody asks, yes, some parts do leak. I don’t remember any of
> them being
> >>> non-functional. However, you don’t test those parts much. They are
> headed to the
> >>> recycle bin.
> >>>
> >>> Bob
> >>
> >> OK. so welded packages (particularly those that are procured for space)
> aren't likely to leak, they tested, etc. I'm sort of interested, though in
> COTS cheap oscillators like these tiny $1 Abracon units. (I don't know
> what they use on Arduinos and RPi, but it's something like this).
> >>
> >> https://www.mouser.com/datasheet/2/3/ASEseries-38758.pdf
> >>
> >> They're sort of silent on the datasheet about sealing, etc. And at
> $1.38 each, do they actually leak test them?
> >>
> >>
> >>
> >>
> >>
> >
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe send an email to time-nuts-leave@lists.febo.com
--
--Eric
_________________________________________
Eric Garner
TV
Tom Van Baak
Tue, Dec 13, 2022 6:26 PM
In my garage - the work of a weekend.
After you stop at the industrial gas or party store to pick up bottles
of He and H, stop at a tire shop and have them remove both rear tires.
Throw half a dozen SMD oscillators inside each one, and re-fill one tire
with He and the other with H. Drive around for a day or two (or until
one or both tires go flat), remove the oscillators, and measure them.
This method not only tests He and H gas leakage but also mimics the
acceleration violence of launch and periods of gravity free-fall. No
chamber necessary. And you have to drive to pickup and return the
bottles anyway.
/tvb
> In my garage - the work of a weekend.
After you stop at the industrial gas or party store to pick up bottles
of He and H, stop at a tire shop and have them remove both rear tires.
Throw half a dozen SMD oscillators inside each one, and re-fill one tire
with He and the other with H. Drive around for a day or two (or until
one or both tires go flat), remove the oscillators, and measure them.
This method not only tests He and H gas leakage but also mimics the
acceleration violence of launch and periods of gravity free-fall. No
chamber necessary. And you have to drive to pickup and return the
bottles anyway.
/tvb
LJ
Lux, Jim
Tue, Dec 13, 2022 7:16 PM
On 12/13/22 10:26 AM, Tom Van Baak via time-nuts wrote:
In my garage - the work of a weekend.
After you stop at the industrial gas or party store to pick up bottles
of He and H, stop at a tire shop and have them remove both rear tires.
Throw half a dozen SMD oscillators inside each one, and re-fill one
tire with He and the other with H. Drive around for a day or two (or
until one or both tires go flat), remove the oscillators, and measure
them.
This method not only tests He and H gas leakage but also mimics the
acceleration violence of launch and periods of gravity free-fall. No
chamber necessary. And you have to drive to pickup and return the
bottles anyway.
You're assuming I don't happen to have a bottle of He or H2 at home (or
at a friend's house), and a pressure pot <grin>. These things are tiny..
I could probably electrolyze water to make enough H2 and use a spare air
cylinder with a weight to pressurize it.
But I like the idea of the field expedient vibe/shock test.
On 12/13/22 10:26 AM, Tom Van Baak via time-nuts wrote:
> > In my garage - the work of a weekend.
>
> After you stop at the industrial gas or party store to pick up bottles
> of He and H, stop at a tire shop and have them remove both rear tires.
> Throw half a dozen SMD oscillators inside each one, and re-fill one
> tire with He and the other with H. Drive around for a day or two (or
> until one or both tires go flat), remove the oscillators, and measure
> them.
>
> This method not only tests He and H gas leakage but also mimics the
> acceleration violence of launch and periods of gravity free-fall. No
> chamber necessary. And you have to drive to pickup and return the
> bottles anyway.
You're assuming I don't happen to have a bottle of He or H2 at home (or
at a friend's house), and a pressure pot <grin>. These things are tiny..
I could probably electrolyze water to make enough H2 and use a spare air
cylinder with a weight to pressurize it.
But I like the idea of the field expedient vibe/shock test.
BC
Bob Camp
Tue, Dec 13, 2022 7:48 PM
Hi
The MIL-STD 202 folks seemed to be quite happy with a 10% mix of He and whatever. My guess is
that you could fill the pressure chamber with your water sourced H2 and then blow it up to 50 PSI
with the shop compressor.
The obvious disadvantage of any process using H2 is fire / explosion. I’m not 100% sure this is the
approach I’d want to take …..
Bob
On Dec 13, 2022, at 2:16 PM, Lux, Jim via time-nuts time-nuts@lists.febo.com wrote:
On 12/13/22 10:26 AM, Tom Van Baak via time-nuts wrote:
In my garage - the work of a weekend.
After you stop at the industrial gas or party store to pick up bottles of He and H, stop at a tire shop and have them remove both rear tires. Throw half a dozen SMD oscillators inside each one, and re-fill one tire with He and the other with H. Drive around for a day or two (or until one or both tires go flat), remove the oscillators, and measure them.
This method not only tests He and H gas leakage but also mimics the acceleration violence of launch and periods of gravity free-fall. No chamber necessary. And you have to drive to pickup and return the bottles anyway.
You're assuming I don't happen to have a bottle of He or H2 at home (or at a friend's house), and a pressure pot <grin>. These things are tiny.. I could probably electrolyze water to make enough H2 and use a spare air cylinder with a weight to pressurize it.
But I like the idea of the field expedient vibe/shock test.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
Hi
The MIL-STD 202 folks seemed to be quite happy with a 10% mix of He and whatever. My guess is
that you could fill the pressure chamber with your water sourced H2 and then blow it up to 50 PSI
with the shop compressor.
The obvious disadvantage of any process using H2 is fire / explosion. I’m not 100% sure this is the
approach I’d want to take …..
Bob
> On Dec 13, 2022, at 2:16 PM, Lux, Jim via time-nuts <time-nuts@lists.febo.com> wrote:
>
> On 12/13/22 10:26 AM, Tom Van Baak via time-nuts wrote:
>> > In my garage - the work of a weekend.
>>
>> After you stop at the industrial gas or party store to pick up bottles of He and H, stop at a tire shop and have them remove both rear tires. Throw half a dozen SMD oscillators inside each one, and re-fill one tire with He and the other with H. Drive around for a day or two (or until one or both tires go flat), remove the oscillators, and measure them.
>>
>> This method not only tests He and H gas leakage but also mimics the acceleration violence of launch and periods of gravity free-fall. No chamber necessary. And you have to drive to pickup and return the bottles anyway.
>
>
> You're assuming I don't happen to have a bottle of He or H2 at home (or at a friend's house), and a pressure pot <grin>. These things are tiny.. I could probably electrolyze water to make enough H2 and use a spare air cylinder with a weight to pressurize it.
>
> But I like the idea of the field expedient vibe/shock test.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe send an email to time-nuts-leave@lists.febo.com
DG
Dr. Geophysics
Tue, Dec 13, 2022 8:36 PM
There has been a lot of work with respect to hydrogen sulfide interaction
with steel in the hydrocarbon area.
Hydrogen embrittlement might be a useful search term for your
investigation. A believe that the American Gas Institute (AGI) did a
couple of webinars about this topic. You can probably find them online.
They were quite informative.
Be extremely extremely extremely cautious working around hydrogen.
On Mon, Dec 12, 2022 at 10:04, Lux, Jim via time-nuts <
time-nuts@lists.febo.com> wrote:
OK, here's an interesting one for you all:
Does anyone have any information on what happens to hermetic TCXOs when
they're in a hydrogen rich atmosphere? There's stories about MRI machine
He rich environments killing Apple watches - I think, though, that was a
MEMS oscillator. The data shows a reduction in Q because the resonator's
not in a vacuum. And I'm aware of pressure sensors failing because they
rely on a vacuum for comparison. But I wouldn't necessarily think this
is the case with a quartz crystal. Or is it? H2 is somewhat more
reactive than He, too.
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
There has been a lot of work with respect to hydrogen sulfide interaction
with steel in the hydrocarbon area.
Hydrogen embrittlement might be a useful search term for your
investigation. A believe that the American Gas Institute (AGI) did a
couple of webinars about this topic. You can probably find them online.
They were quite informative.
Be extremely extremely extremely cautious working around hydrogen.
On Mon, Dec 12, 2022 at 10:04, Lux, Jim via time-nuts <
time-nuts@lists.febo.com> wrote:
> OK, here's an interesting one for you all:
>
> Does anyone have any information on what happens to hermetic TCXOs when
> they're in a hydrogen rich atmosphere? There's stories about MRI machine
> He rich environments killing Apple watches - I think, though, that was a
> MEMS oscillator. The data shows a reduction in Q because the resonator's
> not in a vacuum. And I'm aware of pressure sensors failing because they
> rely on a vacuum for comparison. But I wouldn't necessarily think this
> is the case with a quartz crystal. Or is it? H2 is somewhat more
> reactive than He, too.
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe send an email to time-nuts-leave@lists.febo.com
--
Dr. Geophysics
http://dr.geophysics.googlepages.com
LJ
Lux, Jim
Tue, Dec 13, 2022 9:10 PM
On 12/13/22 11:48 AM, Bob Camp wrote:
Hi
The MIL-STD 202 folks seemed to be quite happy with a 10% mix of He and whatever. My guess is
that you could fill the pressure chamber with your water sourced H2 and then blow it up to 50 PSI
with the shop compressor.
The obvious disadvantage of any process using H2 is fire / explosion. I’m not 100% sure this is the
approach I’d want to take …..
yeah, since the flammable range for H2 is pretty wide.
So do it in the back yard, not the garage or living room.
And if it's just a few cc of H2, I'd think the pressure pot would
contain any "momentary overpressure"
This does bring up an interesting idea for time-nut-ty experimentation.
Is there a cheap connector/feedthrough that can take 100 psi or so to be
able to make measurements "in-situ"? Hermetic RF connectors are
available (not cheap new, but perhaps surplus), but I've only used them
for 15 psi differential (e.g. atmosphere outside to vacuum inside). I've
also used non-resistor spark plugs as HV hermetic feed throughs (there's
some specific Champion number that has a particularly long reach).
Something like a D-sub with a dozen or so pins might be convenient,
especially if it's round (since round holes are easier to drill)
On 12/13/22 11:48 AM, Bob Camp wrote:
> Hi
>
> The MIL-STD 202 folks seemed to be quite happy with a 10% mix of He and whatever. My guess is
> that you could fill the pressure chamber with your water sourced H2 and then blow it up to 50 PSI
> with the shop compressor.
>
> The obvious disadvantage of any process using H2 is fire / explosion. I’m not 100% sure this is the
> approach I’d want to take …..
yeah, since the flammable range for H2 is pretty wide.
So do it in the back yard, not the garage or living room.
And if it's just a few cc of H2, I'd think the pressure pot would
contain any "momentary overpressure"
This does bring up an interesting idea for time-nut-ty experimentation.
Is there a cheap connector/feedthrough that can take 100 psi or so to be
able to make measurements "in-situ"? Hermetic RF connectors are
available (not cheap new, but perhaps surplus), but I've only used them
for 15 psi differential (e.g. atmosphere outside to vacuum inside). I've
also used non-resistor spark plugs as HV hermetic feed throughs (there's
some specific Champion number that has a particularly long reach).
Something like a D-sub with a dozen or so pins might be convenient,
especially if it's round (since round holes are easier to drill)
