[RASMB] Rucrrent Dirty Lamp & Maybe Slow to Pump Down

[John J. Correia]

Peter, Sometimes the gasket in the lamp is misseated. Or the lamp doesn't sit right in the housing. Do you have the window that is inserted above the lamp? It helps with avoiding cleaning. 
Certainly oil can be an issue if you don't have a turbo molecular pump. But start simple.

Sent from my iPhone

On Feb 16, 2012, at 5:22 PM, "Borries Demeler" <demeler at biochem.uthscsa.edu> wrote:

> Peter:
> Any chance you somehow get oil into the chamber? If you have a diffusion
> pump this may be the problem, and more likely if you run at higher
> temperature. Otherwise, are there other sources of dust/dirt in your
> environment that could excluded?
> 
> -borries
> 
> 
> 
> 
> On Thu, Feb 16, 2012 at 09:56:07PM +0000, Peter Edward Prevelige Jr wrote:
>> Hi All -
>> 
>> I am having trouble with my lamp getting dirty after only a couple of days. The instrument was just serviced. A new lamp and gasket  were installed because of a vacuum leak and afterward the lamp intensity and noise level looked great.
>> 
>> A couple of runs later the noise @280 was too high and when I checked the UV intensity it was down to maybe 4K at the 230 peak. Cleaned  & aligned the lamp and it was back up to 15K+ counts. Three days and 4 SedV runs and was back down to 4K. Cleaned and aligned it and it is back up to 17K counts.  My impression also is that it is slow to pump down but this is of course subjective.
>> 
>> It seems like it is getting dirty much too fast. Certainly we never had to clean it after every few runs. In any case, it seems to be getting dirty too fast for a good Sed EQ run in the far UV at any rate. Any suggestions on what to look for/do?
>> 
>> Thanks
>> 
>> Peter
>> 
>> 
>> 
>> 
>> Peter E. Prevelige Jr.
>> Professor
>> Dept. of Microbiology, BBRB 416/6
>> Univ. of Alabama @ Birmingham
>> 845 19th St. South
>> Birmingham AL. 35294-2170
>> Phone 205 975-5327
>> FAX 205 975-5479
>> prevelig at uab.edu<mailto:prevelig at uab.edu>
>> http://www.microbio.uab.edu/faculty/prevelige/prevelige-p.htm
>> 
> 
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