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Hi Karl,<br>
The XLA/I is far better at resisting vibrations (especially high
frequency vibrations like you are describing) than the Model E was, and
you will probably be OK. However, I would not tempt fate by putting the
machine in an area where the vibrations are so bad if you have a
choice. If you have no choice, then you might run a simple test to see
if the vibrations are coupling to the rotor stability. To do this make
a sharp meniscus (either a synthetic boundary cell or a "missing rib"
cell) and monitor the position of the meniscus over time using the
interferometer, and do so at various rotor speeds. Look for both
vibration (periods < 2-3 seconds) and precession (period > 10
seconds). Be sure the cells are balanced... misbalancing the cells is
more likely to cause precession than vibrations. Rotor instability is
speed dependent, with concerns below ~3000 rpm (the meniscus test gets
problematic because of the "slump" of the fluid), with the 8-10 krpm
range also being more subject to trouble (just like the Model E...
there is a node there for the XLI).<br>
When properly focused, you will be able to detect vibrations/precession
to ~10 microns. If you do not see shifts greater than the resolution of
the interferometer, you are doing fine. If the precession is greater
than 10 microns, double check that the cells are balanced, rerun the
test, and if it is still bad, you may need to dampen the vibrations.
That could be the subject of another e-mail.<br>
Best wishes,<br>
Tom <br>
<br>
<a class="moz-txt-link-abbreviated" href="mailto:Karl.Maluf@uchsc.edu">Karl.Maluf@uchsc.edu</a> wrote:<br>
<blockquote
cite="mid678D70FC0009964F88F92D73D987F93101F2D86A@hscex4.uchsc.edu"
type="cite">
<meta http-equiv="Content-Type" content="text/html; ">
<div>Dear All,</div>
<div> </div>
<div>We recently purchased an XLA, and are trying to find space for
it. The problem we have is that the floor we are on vibrates a
little. For example, if you look at a liquid solution, you can see it
vibrate, and sometimes, you can actually feel the vibrations. So the
question is whether these vibrations could affect the XLA? Is the XLA
sufficiently heavy to invalidate this concern? Any advice would be
appreciated.</div>
<div> </div>
<div>Thanks,</div>
<div>Karl Maluf</div>
<div>UCHSC, Denver CO.</div>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Department of Biochemistry and Molecular Biology
University of New Hampshire
Durham, NH 03824-3544
Phone: 603-862-2459
FAX: 603-862-0031
E-mail: <a class="moz-txt-link-abbreviated" href="mailto:Tom.Laue@unh.edu">Tom.Laue@unh.edu</a>
<a class="moz-txt-link-abbreviated" href="http://www.bitc.unh.edu">www.bitc.unh.edu</a>
<a class="moz-txt-link-abbreviated" href="http://www.camis.unh.edu">www.camis.unh.edu</a></pre>
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