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<DIV><FONT face=Arial size=2>Hi Karen and colleagues,</FONT></DIV>
<DIV><FONT face=Arial size=2>I can tell you only from my own experience
how I treat this problem. First of all I use only
sapphire windows,</FONT></DIV>
<DIV><FONT face=Arial size=2>since at the end they are cheaper
then many broken quartz windows. Why broken ? my cell-stuff is
very old so </FONT></DIV>
<DIV><FONT face=Arial size=2>Epoxy centerpieces (alum-filled and
charcoal-filled) swell slowly and became a bit convext on both flat
side , so I</FONT></DIV>
<DIV><FONT face=Arial size=2>even install (not too easy) in case of
the bad once <STRONG>DS-window gaskets</STRONG> between the window
and the centerpiece.</FONT></DIV>
<DIV><FONT face=Arial size=2>as it is obligatory for metallic
centerpieces!! </FONT></DIV>
<DIV><FONT face=Arial size=2>Sure that in case of metllic centerpiece the
torque strength is more crucial since lack of elasticity
you <STRONG>break easier </STRONG></FONT></DIV>
<DIV><FONT face=Arial size=2><STRONG>the window</STRONG> just during
closing the cell (not the centerpiece as you wrote ,Karen ! )
so 130 torque -units should be enough. A probleme may
be the temperature, I torque the cell at
the (coldest) temperature the run is planed , independend if I
fill the cell at room temp.( if the sample allows it). The idea is to
prevent shrinking later of the centerpiece....and leaking. A bit
tolerance for higher temp. is still given with 130
t.</FONT></DIV>
<DIV><FONT face=Arial size=2>The Epoxy once "suffer" more tolerance, so
120 -140 is OK.</FONT></DIV>
<DIV><FONT face=Arial size=2>With time usually one gets the feeling witout
looking on the torque dial especially using Epoxy once ,
according the</FONT></DIV>
<DIV><FONT face=Arial size=2>flexibility.</FONT></DIV>
<DIV><FONT face=Arial size=2> I don't believe that the torque
instrument is a so precise instrument and unic by all users
!!!</FONT></DIV>
<DIV><FONT face=Arial size=2>It may happen (I believe at most of you) that
the screw-ring -gasket do not lie properly on top of the upper window-
holder (catched in the winding or an alien element is between) breaks
, and as response you may read a high torque </FONT></DIV>
<DIV><FONT face=Arial size=2>dial but in realty <STRONG>the centerpiece is not
pressed</STRONG> to the windows.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Just returning to <STRONG>centerpiece
break</STRONG> during a run , usually happens with
quartz widows. First you have a leak</FONT></DIV>
<DIV><FONT face=Arial size=2>in one sector (may be evaporation true
the filling screw), the filling hight liquid remain much higher
as in the other sector, then the midle strap breaks and also</FONT></DIV>
<DIV><FONT face=Arial size=2>mostly the quartz window. (Saphire even
at max.speed never break.)</FONT></DIV>
<DIV><FONT face=Arial
size=2>
yours...ariel</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>!</FONT></DIV>
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