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Minimum Humidity for long term storage of computer equipment?

L

Lostgallifreyan

Jan 1, 1970
0
Good point, Aluminum Electrolytic capacitors may not work after 10 years.

I think they'll hold up quite well. Not sure about depolarising, but I've
found a lot of gear works fine after twenty years or more of storage in a
cool dry cupboard, even with electrolytics in. I bet those computers were
built with high quality caps too. If you avoid changes of heat and
pressure, you'll avoid the most degrading effects on them.

What will help is if you power up the machines every five years and let
them run for a week or two, and like someone else said, batteries are a
dreadful risk, so remove all of them during storage.
 
L

Lostgallifreyan

Jan 1, 1970
0
How can I get nitrogen least expensively?

Probably welders gas cannisters. They'll be cheap because they're made for
a very wide market. They might not be ultra dry but you'll be using
dessicant. They will be fairly pure though, because any oxygen is really
bad for welding, the gas must be very inert.
 
P

Peter Olcott

Jan 1, 1970
0
Lostgallifreyan said:
I think they'll hold up quite well. Not sure about depolarising, but I've
found a lot of gear works fine after twenty years or more of storage in a
cool dry cupboard, even with electrolytics in. I bet those computers were
built with high quality caps too. If you avoid changes of heat and
pressure, you'll avoid the most degrading effects on them.

What will help is if you power up the machines every five years and let
them run for a week or two, and like someone else said, batteries are a
dreadful risk, so remove all of them during storage.

Even the Lithuim Coin Cells?
 
L

Lostgallifreyan

Jan 1, 1970
0
Even the Lithuim Coin Cells?

Yes, because their content is HIGHLY corrosive, and in a confined space is
risky as hell if they outgas for any reason.

They'll be backing up the BIOS config, so you will want something that can
read that and back it up to file, and restore it at will. The interweb is
most bountiful, but you'll have to test carefully to see if those machines
have a BIOS that can be read by whatever tool you find. You could also note
the settings on paper, I bet those BIOS's don't have many things to
remember.
 
In sci.electronics.design Peter Olcott said:
I want to store the computers because there has only been one
computer made that I can use in direct sunlight, fit inside my
pocket, with a large enough screen and keyboard that I can do
C++ programming. HP 200LX. They quit making these ten years ago,
and no one has made anything like them since. I bought four of them
so that I will never run out.

This ..?
http://www.daniel-hertrich.de/200lx/

Anyway the only thing I can think is hard to aquire is the screen and keyboard.
The rest should be even easier to make these days. Should you want to make a
duplicate ;)

Other than that I think hermeticly sealed plastic or welded steelbox filled
with nitrogen. Then store it inside some space that has large
mass to even out temperature.
 
P

Peter Olcott

Jan 1, 1970
0
Lostgallifreyan said:
Yes, because their content is HIGHLY corrosive, and in a confined space is
risky as hell if they outgas for any reason.

They'll be backing up the BIOS config, so you will want something that can
read that and back it up to file, and restore it at will. The interweb is
most bountiful, but you'll have to test carefully to see if those machines
have a BIOS that can be read by whatever tool you find. You could also note
the settings on paper, I bet those BIOS's don't have many things to
remember.

These handheld units always prompt you for all the bios settings whenever both
of the batteries are removed. The bios setting are really trivial, owner name
and such.
 
P

Peter Olcott

Jan 1, 1970
0
This ..?
http://www.daniel-hertrich.de/200lx/

Anyway the only thing I can think is hard to aquire is the screen and
keyboard.
The rest should be even easier to make these days. Should you want to make a
duplicate ;)

Other than that I think hermeticly sealed plastic or welded steelbox filled
with nitrogen. Then store it inside some space that has large
mass to even out temperature.

I have the maximum sized drawer (10" * 10" * 22") in my bank vault. The unit
itself is the size of a checkbook, and one inch thick. I can use my foodsaver
machine to hermetically seal the 2 mil bags. After I fill the bags with nitrogen
won't it take awhile to reach all of the air inside the computer? I was thinking
something like fill seal, wait overnight poke a small hole and refill and
reseal. I am hoping that I can rent a very small tank of nitrogen.
 
L

Lostgallifreyan

Jan 1, 1970
0
I have the maximum sized drawer (10" * 10" * 22") in my bank vault.
The unit itself is the size of a checkbook, and one inch thick. I can
use my foodsaver machine to hermetically seal the 2 mil bags. After I
fill the bags with nitrogen won't it take awhile to reach all of the
air inside the computer? I was thinking something like fill seal, wait
overnight poke a small hole and refill and reseal. I am hoping that I
can rent a very small tank of nitrogen.

I thought of that and forgot to add it to any of my posts... If you can get
a small tube to match to a hole somewhere in the case, get the gas in
through that to displace the air, because if you use a food pack sealer
you'll otherwise trap a higher proportion of air than clean nitrogen when
the bag contratcs round the case.

It might be harder to handle that method anyway, and a loose wrap is
better for maintaining atmosperic pressure. I'd just use decent clear
polythene bags (ideal material, used in ultra stable capacitor dielectrics,
as it happens). I'd bunch the open end round the gas tube with the computer
inside, with a rubber band to keep the bag neck closed, and have another
short bit of tube in the neck to let air out. I'd navigate the main tube
end so it flushed the computer through a case hole, and run it for a couple
of minutes, lightly squeezing the bag like a bagpipe to make the gas
flush more efficient. This way it won't matter if the gas expands enough to
cool below ambient heat and cause condensation, it will settle on the
outside of the bag, not the inside. :) Then I'd pull both tubes out quickly
so the rubber band tightened to part-seal the bag. I'd bunch the open end
and twist it tight, then use a cigaretter lighter or candle to melt the end
like I was sealing a nylon rope end. No fumes will get into the machine,
the few that could get down the twisted polythene would be stopped by the
rubber band. Then I'd pack it loosely into a cardboard box after gently
squeezing for a few tens of seconds to make sure that it wasn't deflating
though a leak.

Seriously, sometimes a well-thought crude method wil get you far better
results. By the time you'd got your gas-filled package ready for that food
sealer, you'd maybe have lost half your bagged nitrogen through a big open
gap and replaced it with air. A bit of dexterity will do more than a
machine will do, and at far less cost.


Btw, what kind of cost are these machines? I saw a few pages online, but
few that mention money.
 
P

Peter Olcott

Jan 1, 1970
0
Lostgallifreyan said:
I thought of that and forgot to add it to any of my posts... If you can get
a small tube to match to a hole somewhere in the case, get the gas in
through that to displace the air, because if you use a food pack sealer
you'll otherwise trap a higher proportion of air than clean nitrogen when
the bag contratcs round the case.

It might be harder to handle that method anyway, and a loose wrap is
better for maintaining atmosperic pressure. I'd just use decent clear
polythene bags (ideal material, used in ultra stable capacitor dielectrics,
as it happens). I'd bunch the open end round the gas tube with the computer
inside, with a rubber band to keep the bag neck closed, and have another
short bit of tube in the neck to let air out. I'd navigate the main tube
end so it flushed the computer through a case hole, and run it for a couple
of minutes, lightly squeezing the bag like a bagpipe to make the gas
flush more efficient. This way it won't matter if the gas expands enough to
cool below ambient heat and cause condensation, it will settle on the
outside of the bag, not the inside. :) Then I'd pull both tubes out quickly
so the rubber band tightened to part-seal the bag. I'd bunch the open end
and twist it tight, then use a cigaretter lighter or candle to melt the end
like I was sealing a nylon rope end. No fumes will get into the machine,
the few that could get down the twisted polythene would be stopped by the
rubber band. Then I'd pack it loosely into a cardboard box after gently
squeezing for a few tens of seconds to make sure that it wasn't deflating
though a leak.

Seriously, sometimes a well-thought crude method wil get you far better
results. By the time you'd got your gas-filled package ready for that food
sealer, you'd maybe have lost half your bagged nitrogen through a big open
gap and replaced it with air. A bit of dexterity will do more than a
machine will do, and at far less cost.


Btw, what kind of cost are these machines? I saw a few pages online, but
few that mention money.

I got a brand new discontinued model 345 for $20.
You can get these on Ebay for about $50.
Wal-Mart has a newer model for $75.00

I can adapt my ideas to yours and get a neater seal using the hermetic sealer of
the foodsaver. Now the trick is to get some nitrogen for $10.

I would seal both ends of the bag with plenty of air in the bag.
I could use a hole punch to make a neat round hole just below the seal, before I
Seal it.
From this hole, I flush the bag and the unit with a tube feeding nitrogen, the
air comes out of the same hole that the nitrogen is being fed. Using the same
squeezing method that you mentioned, I continue to do this until the bag is
flushed. While still filling the bag, I pull the tube out and seal the tiny
hole (0.25 inch diameter) with scotch tape. Then I reseal the bag hermetically,
just below this hole.

Both of these methods would seem to reach about a maximum of 95% purity, would
this be enough?
 
L

Lostgallifreyan

Jan 1, 1970
0
I got a brand new discontinued model 345 for $20.
You can get these on Ebay for about $50.
Wal-Mart has a newer model for $75.00

I can adapt my ideas to yours and get a neater seal using the hermetic
sealer of the foodsaver. Now the trick is to get some nitrogen for
$10.

I would seal both ends of the bag with plenty of air in the bag.
I could use a hole punch to make a neat round hole just below the
seal, before I Seal it.
From this hole, I flush the bag and the unit with a tube feeding
nitrogen, the air comes out of the same hole that the nitrogen is
being fed. Using the same squeezing method that you mentioned, I
continue to do this until the bag is flushed. While still filling the
bag, I pull the tube out and seal the tiny hole (0.25 inch diameter)
with scotch tape. Then I reseal the bag hermetically, just below this
hole.

Both of these methods would seem to reach about a maximum of 95%
purity, would this be enough?

Yes :)
 
M

Michael Kennedy

Jan 1, 1970
0
Some paintball shops have nitrogen instead of CO2. It isn't usually very
expensive.

- Mike
 
J

Jasen Betts

Jan 1, 1970
0
Is there a minimum level of relative humidity, below which computer equipment is
damaged?

I bought some antique handheld computers. I want to keep them in pristine
condition for a very long time, fifty years or more. I want to know the ideal
environmental conditions to store these computers. I am probably going to store
these in a bank vault. I can greatly reduce the relative humidity using a
commercial desiccant such as drierite.

Thanks for your help.

you'll need to do something to slow or mitigate leeching of the plasticisers
from the plastic parts (they'll turn brittle). being antiques they won't
have lithium-ion batteries, that's good because storing them long-term could
be a problem.

If these devices have disk drives, cooling fans etc... their lubrication
could be an issue too.

sealing them in a metal container with an inert atmosphere would probably be
better than vacuum pack in a polyethylene bag.

charge leakage in proms could be an issue too, and there's not much that can
be done about that. if they have mask roms instead you're safe .

if they have internal batteries maintaining power to some part of the system
that could be an issue....

basically you have to look at every part and consider what 50 years on the
shelf would do to it.

Bye.
Jasen
 
I

Industrial Electrician

Jan 1, 1970
0
Do *NOT* use CO2 instead on Nitrogen! Any residual moisture will react
with the CO2 and form carbolic acid.

I would also worry about your "vaccuum sealing" plastic. Will it outgass
and stain the surface? Will it stick after many years? At a bare minimum
I would wrap the items in archival-quality acid-free tissue paper before
shrinking the plastic around them. Better yet would be to put the tissue-
wrapped item inside a polyplopylene storage container (tupperware style).
Do it right and it will also protect against moderate banging around.

Be aware that this newgroup contains a mix of wise/experienced people
and morons who will lead you astray. Talk with someone who stores
antique books. The techniques that protect those will work on your
electronic items, with the exception of humidity; I think they like
more than what is best for your application.
 
J

Jasen Betts

Jan 1, 1970
0
What about reducing the relative humidity to zero?

if you're using a dessicant that could draw moisture out of the capacitors
afaik electronics doesn't benefit much from low humidity, that's more an
issue with paper.
I can't go to this extreme, what is the next cheaper option?

All you need for that extreme is to borrow a canning machine
and hire a tank of nitrogen

Plastic wrap leaks, aluminised plastic wrap leaks significantly less. but it
still leaks.

The inside of a pringles tube isn't aluminised to make it look good.

a soldered metal canister is probably the ideal.
 
J

Jasen Betts

Jan 1, 1970
0
The only thing that I would not know how do, after your excellent explanation
would be to find the most cost-effective source of nitrogen gas. It would be
nice If I could buy a couple of cubic feet at Wal-Mart for $2.99.

I saw a sign outside a tyre place advertising nitrogen, go there with a few
dozen baloons, or your spare tyre...
Also would nitrogen gas be reactive with CaSO4, CoCl2 ?
(That is the composition of my "drierite" desiccant).

CoCl2 is highly toxic. are you sure ?

the air is 75% nitrogen. 100% nitrogen is unlikely to react in a way that
75% doesn't

another option is argon gas from a place that welds aluminium. argon won't
react with anything.

Bye.
Jasen
 
P

Peter Olcott

Jan 1, 1970
0
Jasen Betts said:
you'll need to do something to slow or mitigate leeching of the plasticisers
from the plastic parts (they'll turn brittle). being antiques they won't
have lithium-ion batteries, that's good because storing them long-term could
be a problem.

If these devices have disk drives, cooling fans etc... their lubrication
could be an issue too.
They are using flash RAM.
sealing them in a metal container with an inert atmosphere would probably be
better than vacuum pack in a polyethylene bag.

What about sealing them in a 2 mil plastic bag in nitrogen?
charge leakage in proms could be an issue too, and there's not much that can
be done about that. if they have mask roms instead you're safe .

I think that it is regular ROM. Someone said somthing about capacitors.
 
P

Peter Olcott

Jan 1, 1970
0
Industrial Electrician said:
Do *NOT* use CO2 instead on Nitrogen! Any residual moisture will react with
the CO2 and form carbolic acid.

I would also worry about your "vaccuum sealing" plastic. Will it outgass
and stain the surface?
I can't tell what you are saying here.
 
P

Peter Olcott

Jan 1, 1970
0
Jasen Betts said:
if you're using a dessicant that could draw moisture out of the capacitors
afaik electronics doesn't benefit much from low humidity, that's more an
issue with paper.
Would this zero relative humidity damage any of the parts?
All you need for that extreme is to borrow a canning machine
and hire a tank of nitrogen

Plastic wrap leaks, aluminised plastic wrap leaks significantly less. but it
still leaks.

Would I be able to continually test for leaks in a regular plastic bag? I can
easily check on these items annually.
 
P

Peter Olcott

Jan 1, 1970
0
Jasen Betts said:
I saw a sign outside a tyre place advertising nitrogen, go there with a few
dozen baloons, or your spare tyre...



CoCl2 is highly toxic. are you sure ?
That is not a C-Twelve its CL2. I am sure its right on the jar.
 
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