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<DIV><FONT face=Arial size=2><SPAN class=510510913-29042010>Dear
colleagues,</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=510510913-29042010></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=510510913-29042010>we recently
encounter problems with the interference optical system on our XLI (upgraded to
Proteome Lab version) in that the fringe pattern looks very dark (please see
attached screenshots). Beckman field service recommended to us to clean the
lenses in the laser housing of the monochomator arm (which we did paying
attention to reinstall the lens in the correct orientation) and to
clean/exchange the filter above the condensor lens. While intermittantly the
brightness/contrast of the fringe pattern improved, we are back to "very dark"
after trying to further clean things up. What remains also is a concentric
interference pattern superimposed to the expected fringes, which you can see on
the left side of the fringe patttern in the second screen shot. This ghost
pattern is also visible when we look at the scallop position or an empty cell
hole.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN class=510510913-29042010>Any suggestion as to
how we can get our machine back to normal would be greatly
apprecieated.</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=510510913-29042010></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN class=510510913-29042010>Best
regards,</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=510510913-29042010></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN
class=510510913-29042010>Arne</SPAN></FONT></DIV>
<DIV><FONT face=Arial size=2><SPAN
class=510510913-29042010></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN
class=510510913-29042010></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN
class=510510913-29042010></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN
class=510510913-29042010></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2><SPAN
class=510510913-29042010></SPAN></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV align=left>
<DIV align=left><FONT face=Arial size=2>Dr. Arne Rufer</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>F. Hoffmann-La Roche AG</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>PROBMO Optical Spectroscopy</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>065/207</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>CH-4070 Basel</FONT></DIV>
<DIV align=left><FONT face=Arial size=2>Tel: 0041-(0)61-6882126</FONT></DIV>
<DIV align=left><FONT face=Arial size=2><A
href="mailto:arne.rufer@roche.com">arne.rufer@roche.com</A></FONT></DIV></DIV>
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