[RASMB] condensation

[Chad Brautigam]

Hi, Borries,

The condensation has been occurring during 20 deg. C runs.  We have  
rarely had problems with condensation using this temperature in the  
past.  Recently, before this problem came up, a user did a run at 37  
deg. C, and there was definitely condensation on the filter after  
that run.  I wasn't surprised by that, but I am surprised by the  
consistent fogging that we are now getting at 20 deg. C.

Would anyone like to comment on the cost of a turbomolecular pump?

Chad

On Jun 4, 2008, at 12:30 PM, Borries Demeler wrote:

>>
>> Dear All,
>>
>> We're having a serious problem with our XL-I.  The UV filter that is
>> positioned over the condenser lens is fogging with oil every time it
>> is used.  It is the underside of the filter that gets fogged.
>> Fogging, of course, completely negates our ability to use the
>> interference optics.  A Beckman service rep recently changed the
>> condenser lens and also replaced our vacuum pump.  Does anyone have
>> any notion of why this fogging is occurring and what the fix might
>> be?  Our service rep is trying hard to get this fixed, but he is new
>> to the analytical centrifuges.  Any help the community can offer
>> would be greatly appreciated.
>>
>> Chad
>
> Hi Chad,
>
> oil condensation seems to be a common problem with the XLA/I. In my  
> experience
> this problem is minimized when running at lower temperature, and  
> aggravated
> when running at temps higher than 25C. I think the only surefire  
> solution
> is to replace the pump with a turbomolecular pump. You may want to  
> check
> with Walter Stafford, I believe he has made such a retrofit to his  
> machine.
>
> Regards, -Borries
> _______________________________________________
> RASMB mailing list
> RASMB at rasmb.bbri.org
> http://rasmb.bbri.org/mailman/listinfo/rasmb

======================================
Chad A. Brautigam, Ph.D.
Assistant Professor
Department of Biochemistry
The University of Texas
Southwestern Medical Center at Dallas
Department of Biochemistry
5323 Harry Hines Blvd.
Dallas, TX 75390-8816
Office:  214-645-6384
Fax:  214-645-6353
Email:  chad.brautigam at utsouthwestern.edu



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.rasmb.org/pipermail/rasmb-rasmb.org/attachments/20080604/7f0355e0/attachment.htm>