[RASMB] lamp intensity drop

[Peter Schuck]

This may not be related, but it reminds me on a problem we had on one 
machine about a year ago, where mysteriously during a velocity run the 
intensity at 255 nm (that's where we scanned) seemed to decrease and the 
scans became very noisy.  The first 20 - 30 scans were perfectly fine, 
and then all scans were extremely noisy.  When only a single scan was 
started afterwards (cold) to test the intensity, it seemed fine, but 
everytime during the velocity run it decreased again after a while.  Our 
service engineer was able to trace it down to what I seem to remember 
was a space somehow created by the lamp housing or a cover, that was in 
the light path but apparently didn't get evacuated and trapped O2 
forming ozone after a while.  (Sorry for the poor description, but I can 
find out exactly what it was if somebody has the same problem.)

Peter