[RASMB] Xl-I wavelength check question

[Borries Demeler]

> Many thanks to everyone for the responses.
> 
> I decided to use a cell housing containing two window assembly's, a =
> centerpiece, and screwring but no windows. This was put into rotor hole 4 =
> and I removed any extra weights from the counterbalance to bring the =
> masses of both within 3 g. The wavelength accuracy test was then quite =
> simple.
> 
> The peak at 230 nm has intensity of around 7500, and the peak at 530 nm =
> has intensity of around 2000. The Beckman manual says intensity under 6000 =
> for the 230 nm peak indicates the lamp requires cleaned, whilst Karel and =
> Virgil's excellent User Guide suggests that intensity should be 15000 or =
> greater. As I am in the process of upgrading some of the components, =
> including, hopefully, the PC, I will have the Beckman service engineer =
> clean the lamp anyway in the near future.
> 
> Thanks to all once again.
> 
> Mark
> 

Hi Mark,
I should mention that we have to clean our lamps quite regularly, depending
on use perhaps every 2-3 weeks. The procedure is simple enough, it would be
worthwhile to have the service person teach you how to do it yourself. 
Sometimes other optical components also require cleaning, but the lamp
is usually the biggest culprit. Lamps do vary in intensity at 230 nm, most
I have come across range between 12-30 kcounts when cleaned. The UV intensity
is lost first, I guess dirt absorbs in the UV stronger than in the vis.

Regards, -Borries