[RASMB] cleaning the lens

[Les Hicks]

Hi Judith,

    I have had this happen very often with our XL-I, though usually only
when running at  low or high temperatures (I very rarely see it when running
at 20 - 25 deg. C).  Apparently Beckman thinks it is oil mist from either
vacuum pump or diffusion pump oil.  The service rep for our area recommended
removing the lens cover (I assume it's the lens cover you're referring to)
and cleaning it thoroughly with alcohol and then deionized H20 using lens
tissue or other such non abrasive tissue to ensure you don't scratch the
lens cover.  I use Nitrogen to blow all the lint off of it before
reinstalling in the centrifuge.  To prevent it from happening again he
suggested applying a VERY small amount of Spinkote on the threads of the
lens cover to help form a seal when it is screwed back in place.  The
interesting point in all of this is that the misting always occurs on the
bottom surface of the lens cover and not the upper surface.  I found that
the Spinkote helps a bit, but that I still occasionally get the misting.
The last time I cleaned it I tried applying vacuum grease (again a VERY
small amount) on the threads and so far the problem hasn't re-occurred, but
I'll need to perform a few more runs before I can determine whether it is
going to be a long term solution.

Best of luck,

Les Hicks

--------------------------------------------------------------------
Les Hicks
PENCE / Dept. of Biochemistry
Rm 3-34 Medical Sciences Bldg.
University of Alberta
Edmonton, Alberta, Canada
T6G 2H7

Phone : 780-492-3412
Cell     : 780-717-0515
FAX    : 780-492-0095
email   : hicks at ualberta.ca
--------------------------------------------------------------------





----- Original Message -----
From: "Mary Judith Kornblatt" <judithk at vax2.concordia.ca>
To: <rasmb at server1.bbri.org>
Sent: Tuesday, April 23, 2002 8:27 AM
Subject: [RASMB] cleaning the lens


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> We appear to have moisture of some sort on the underside of the lens for
the
> interference optics. Can this be cleaned in-house?  Judith Kornblatt
> jack a kornblatt
> enzyme research group
> concordia university
> 1455 de maisonneuve ouest
> montreal, qc, canada h3g 1m8
> tel 1 514 848 3404, fax 1 514 848 2881
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