Minimum Humidity for long term storage of computer equipment?

Apr 18, 2006 10 Replies

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.


Is the bank vault hermetically sealed? Or your packaging? If not, long term, they will return to ambient conditions.

...Jim Thompson

| James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | Old Latin teachers never die...they just decline

My vacuum packaging is hermetically sealed.

: My vacuum packaging is hermetically sealed.

Might be good if all of this sealing didn't generate Electrostatic Discharge also. Often, pressurized air/vacuum can generate ESD.

I don't know why it's important to keep the computer vs. storing the data instead. It's likely the capacitors will eventually depolarize over time if they're not powered up.

some things to think about....

b.

Good point, Aluminum Electrolytic capacitors may not work after 10 years.

"Ken Finney" wrote in news: snipped-for-privacy@news.boeing.com:

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?

"Peter Olcott" wrote in news:uxe1g.3566$8q.1546@dukeread08:

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.

equipment is

pristine

the ideal

to store

using a

Humidity is the least of your worries. In 50 years every electrolytic capacitor in those machines will have turned to mush - the machines will not be usuable. I don't know what the storage life of a EPROM or flash memory is, but I doubt that is 50 years, either. The commercial life of these machines was measured in months - they weren't really designed for long-term storage. Low temperature might help - keep them down at the low end of the commercial range, toward 0 C, to slow down the bit-rot and electrolytic decay.

Bill

What's the shelf life of modern electrolytics? (Assume room temperature)

What about high temperature or long life models?

What's the shelf life of tantalums?

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