[ATM] Fwd: Re: Testing Tunnel

[Guy Brandenburg]

Dale meant to cc this to the entire list. Here goes.

Dale Eason <atmpob at yahoo.com> wrote: Date: Mon, 2 Apr 2007 09:20:01 -0700 (PDT)
From: Dale Eason <atmpob at yahoo.com>
Subject: Re: [ATM] Testing Tunnel
To: Guy Brandenburg <gfbrandenburg at yahoo.com>

 
--- Guy Brandenburg  wrote:

> Hmm. Thanks for the observations. I guess it will be
> necessary to isolate the testing stand from the
> mirror stand, rather than have them all on the same
> support.
> Vladimir G wants me to invite Dale E to come and
> give a demo/talk on interferometery. Sounds like a
> winner. Dale?
> Guy
> 

We have Dave Rowe to thank for all of this.  Maybe he
can come.  If not...

Try the virtual Dale
http://starryridge.com/mediawiki-1.9.1/index.php?title=Main_Page

I put together most of the FAQ.
I have helped at least two people build and operate
Bath interferometers using email.  Hopefully that will
be enough.  I love demoing gadgets however it is
unlikely that I would be able to come anytime soon.

As Vladimir stated the Bath interferometer is easy to
build and operate.  I think it is about the same as
making and using a Foucault platform with no prior
knowledge.  It does however need a digital camera.  I
have found that a Digital SLR is my best solution so
far.  One can not just look into the interferometer
and figure anything out like they can with a Foucault
test.  Vibration can be an issue.  Using it on an
upper story of a multiple story building may not be
feasible.

They are so cheap and easy to build it does not cost
too much to find out if it usable in your situation.
To do that one does not even need the camera.  A white
card in place of the camera will tell you all you need
to know.  So I tell people make it and try it with the
white card.  Then go to the next step of integrating a
camera which can be as simple as a Digital SLR on a
tripod with at least a 50mm lens.  For an F5 mirror a
135 mm lens on the Digital SLR is ideal.  There are
ways to use point and shoot digitalis as long as they
have manual override of focus and exposure but that is
a complication.


Dale Eason