RE: [APML]: dry air vs. nitrogen purge

[Ben Gomes-Casseres <ben@alliancerevolution.com>]

The Astro-Photography Mailing List
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Chuck et al,

Could you possibly give us a brief sketch of how the N2 purge is done? I 
have been wanting to do it, but have not felt that I knew enough about it 
yet to go ahead and drill a hole in my OM-1...where to drill?...what size 
hole and tubing?...how to regulate flow?....what flow rate?...These are 
some of the questions I have, but there may be others.

Since this is "invasive" surgery on the equipment, I'd love to hear from 
you and others on the "do's" and (especially) the "don'ts"!

FYI, my application will be an OM-1 at prime focus of a 4" refractor which 
is used either with or without a field reducer.

Thanks in advance,

Ben Gomes-Casseres
ben@alliancerevolution.com


-----Original Message-----
From:   Chuck Vaughn [SMTP:aa6g@aa6g.org]
Sent:   Saturday, September 26, 1998 12:32 AM
To:     astro-photo@nightsky.com
Subject:        Re: [APML]: dry air vs. nitrogen purge

The Astro-Photography Mailing List
------------------------------------

Fred,
>
>   Chuck in a recent post you wrote about using a nitrogen purge
>   to suppress moisture effects.
>   Would ambient air run through a drying filter be just as good or
>   you also concerned about the presence of oxygen?

I think dry air would be okay since I don't have a problem on dry
nights with no purge. I don't know how good those drying filters
are.

Chuck <aa6g@aa6g.org>